HK1079368B

HK1079368B - Audio data code conversion transmission method and code conversion reception method, device and system

Info

Publication number: HK1079368B
Application number: HK05111300.7A
Authority: HK
Inventors: 小泽一范; 出井洋明; 幡生敦史
Original assignee: 日本电气株式会社
Priority date: 2002-04-26
Filing date: 2003-04-23
Publication date: 2009-07-03

Description

Audio data code conversion transmitting method and code conversion receiving method, equipment and system

Technical Field

The present invention relates to an audio encoding data transmission technique, and more particularly, to a transcoding and transmission method for transmitting audio encoding data and a transcoding and reception method for receiving encoded and converted audio data; and also relates to a system and an audio transcoding and transmitting device, a transcoding and receiving device, and also to a program for audio transcoding and transmission/audio transcoding and receiving processes to be executed by a computer.

Background

Recently, a method of transmitting high compression rate encoded data according to a Modified Discrete Cosine Transform (MDCT), which is capable of efficiently transmitting audio data, has been widely used. In the method, an audio signal is divided into a plurality of frames, and MDCT is performed on the frames, the number of quantization bits is allocated to MDCT factors according to a psychology audio model, and the MDCT factors are quantized and transmitted. Therefore, by efficiently compressing and encoding data, audio data can be transmitted using a small number of pass bands.

MPEG (moving picture experts group) -4AAC (advanced audio coding) and the like are typical examples thereof.

Disclosure of Invention

However, in the conventional audio transmission method, when a long burst of transmission data error or transmission packet loss occurs and cannot be recovered even with the use of an error detection code, the receiver cannot correctly decode the audio data in the error frame. One possible countermeasure taken by the receiver is to employ an error cancellation method in which the audio signal in the previous frame, in which the data has been correctly decoded, is used instead of the erroneous audio signal. However, in this case, the sound quality will inevitably be reduced. When the coding efficiency is improved by intra-frame prediction of MDCT factors, a problem occurs in that, once deterioration of sound quality occurs, subsequent frames are affected.

In the multicast/broadcast information transmission, the receiver cannot transmit information about transmission data errors or transmission data packets having been lost to the transmitter. When the receiver feeds back error information to the transmitter, the feedback information occupies a frequency band.

The present invention has been developed in order to solve the above-described problems, and its primary object is to provide an audio data transcoding and transmitting method, a receiving method, a device, a system, and a program capable of suppressing severe deterioration of a decoded audio signal caused by erroneous transmission of audio encoded data and suppressing deterioration of the decoded audio signal received by a receiver to an audibility level.

It is a second object of the present invention to provide an audio data transcoding and transmitting method, receiving method, apparatus, system, and program which allow a user to set a tradeoff between a passband available for transmitting audio data and sound quality.

A third object of the present invention is to provide an audio data transcoding and transmitting method, a receiving method, an apparatus, and a program capable of preventing an increase in the complexity of operations required for decoding compressed audio coded data.

A fourth object of the present invention is to provide a method, apparatus, system, and program for achieving the first object without requiring the receiver to transmit feedback information to the transmitter.

An apparatus according to the present invention which achieves at least one of the above objects is a transcoding and transmitting apparatus which inputs audio coded data, converts it and outputs it to a transmission line. The apparatus includes a plurality of audio transcoding and transmitting means for outputting an input audio encoded data stream and audio encoded data obtained by decoding and re-encoding the input audio encoded data, or outputting a plurality of pieces of audio encoded data obtained by re-encoding data obtained by decoding the input audio encoded data. The plurality of audio transcoding and transmitting devices output all or selected portions of the audio encoded data and/or re-encoded audio encoded data and output the plurality of audio encoded data from the plurality of audio transcoding and transmitting devices onto one or more transmission lines. In the present invention, a transcoding and receiving apparatus for receiving audio coded data transmitted from a transcoding and transmitting apparatus onto a transmission line includes means for selecting the transmission line for receiving data from one or more transmission lines, and means for receiving audio coded data from the selected transmission line and recombining the audio coded data based on the correctly received coded data.

The transcoding and transmitting apparatus according to an aspect of the present invention comprises:

(a) a first audio transcoding and transmitting means for inputting compressed audio coded data and outputting all frames of the input audio coded data or partial frames of the input audio coded data;

(b) second to nth (N is a predetermined integer equal to or greater than 2) audio code conversion and transmission means for decoding all or part of input audio coded data and encoding data obtained by decoding the data, and outputting all or part of frames of the obtained coded data; and

(c) transmitting means for transmitting outputs of the first to Nth audio transcoding and transmitting means to first to Mth (M is a predetermined integer equal to or greater than 1) transmission lines.

The transcoding and transmitting apparatus according to another aspect of the present invention comprises:

(a) a first audio transcoding and transmitting means for inputting compressed audio coded data packet data and outputting all or a part of the input audio coded data packets;

(b) second to nth (N is a predetermined integer greater than 2) audio transcoding and transmitting means for decoding input audio coded packet data or data obtained by decoding the data and outputting all or part of the obtained packet data; and

The transcoding and receiving apparatus according to still another aspect of the present invention comprises:

(e) selection means for selecting a transmission line for receiving encoded data from first to Mth transmission lines (M is a predetermined integer equal to or greater than 1); and

(f) and a receiving means for receiving the encoded data from the transmission line selected by the selecting means and extracting the encoded data received without the occurrence of a transmission error or loss, and recombining the encoded data based on the extracted encoded data and outputting the result.

(f) receiving means for receiving the encoded data from the transmission line selected by the selecting means and extracting encoded data packet data received without occurrence of a transmission error or loss, and recombining the encoded data according to the extracted encoded data packet data and outputting the result.

The transcoding and transmitting method according to another aspect of the present invention includes:

(a) the method comprises the following steps: the first audio code conversion and transmission device inputs the compressed audio code data and outputs all frames (or data packets) or partial frames (or data packets) of the input audio code data;

(b) the method comprises the following steps: second to nth (N is a predetermined integer equal to or greater than 2) audio code conversion and transmission devices decode all input audio coded data or a part of the input audio coded data, and encode data obtained by decoding the data, and output all frames (or packets) or a part of frames (or packets) of the obtained coded data; and

(c) the method comprises the following steps: the outputs of the first to Nth audio transcoding and transmitting devices are transmitted to first to Mth transmission lines (M is an integer equal to or greater than 1).

The transcoding and receiving method according to still another aspect of the present invention includes:

(d) the method comprises the following steps: selecting a transmission line for receiving audio-encoded data from first to Mth transmission lines (M is a predetermined integer equal to or greater than 1); and

(e) the method comprises the following steps: receiving the encoded data from the transmission line selected by the selection means, and extracting the audio encoded data (packet) received without transmission error or loss, and recombining the audio encoded data based on the extracted encoded data (packet data) and outputting the result.

A computer program according to another aspect of the present invention for instructing a computer to form a partial audio data transcoding and transmitting apparatus and have first audio transcoding and transmitting means and second to nth (N is a predetermined integer equal to or greater than 2) audio transcoding and transmitting means so as to perform transcoding and transmitting processing on audio coded data, includes:

(a) processing of inputting compressed audio coded data and outputting all or part of frames of the input audio coded data;

(b) a process of decoding all or part of the input audio coded data and encoding data obtained by decoding the data, and outputting all or part of the obtained frames of the encoded data by the second to nth (N is a predetermined integer equal to or greater than 2) audio transcoding and transmitting means; and

(c) and a process of transmitting the outputs of the first to Nth audio transcoding and transmitting apparatuses to first to Mth transmission lines (M is an integer equal to or greater than 1).

A computer program according to another aspect of the present invention for instructing a computer to form an audio data transcoding and receiving apparatus to perform a transcoding process on audio encoded data, includes:

(d) a process of selecting transmission lines to receive encoded data from at least one of M (M is a predetermined integer equal to or greater than 1) transmission lines; and

(e) a process of receiving encoded data from a selected transmission line and extracting audio encoded data (packet data) received without transmission error or loss, and recombining the audio encoded data according to the extracted encoded data (packet data) and outputting the result.

In the present invention, in order to prevent sound quality from being extremely deteriorated due to transmission errors of compressed audio encoded data, a transcoding and transmitting apparatus receives the encoded data from an audio encoding apparatus, converts the data into a format that protects the data from loss or errors occurring in a transmission line, and transmits the data to the transcoding and receiving apparatus.

In the present invention, the transcoding and transmitting apparatus includes first to nth audio transcoding and transmitting devices which compress and encode audio data into N coded data pieces and transmit the data to first to nth transmission lines. The transcoding and receiving apparatus selects encoded data of a lowest compression ratio and high sound quality among the encoded data correctly received from the M transmission lines, and decodes the selected data.

In the present invention, the transmission of the N coded data pieces obtained by the first to nth audio transcoding and transmitting apparatuses is scheduled at a predetermined or adaptively variable period.

In the present invention, an transcoding and receiving apparatus selects encoded data of a lowest compression ratio and high sound quality from among encoded data in the form of a correctly received frame or packet unit, the encoded data being from at least one of M transmission lines, and decodes the selected data.

In addition, according to the present invention, compression ratios of the first to nth audio transcoding and transmitting apparatuses may be selected according to available pass bands in the first to mth transmission lines. The second to nth audio transcoding and transmitting apparatuses may encode data at a compression ratio equal to or greater than that of the first audio transcoding and transmitting apparatus, or may arbitrarily set a compression ratio.

In the present invention, in order to prevent an increase in the computational complexity of a receiving side in transmitting a plurality of coded data pieces, a transcoding and transmitting apparatus generates the same coded data frame, and a receiver selects at least one frame or packet of data from the received plurality of coded data pieces, and decodes the selected data.

To be more practical, in the audio data conversion and transmission system according to the first aspect of the present invention, for N greater than or equal to 2 and M greater than or equal to 1, the transcoding and transmission apparatus includes: a) a first audio transcoding and transmitting means for inputting the compressed encoded data and transmitting the entire frame or a part of the frame adaptively selected according to the characteristics of the input audio or according to a predetermined rule using a predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting means for decoding input encoded data and compressing and transmitting the encoded data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting means, and transmitting all frames of the obtained encoded data or transmitting partial frames adaptively selected according to characteristics of the input audio data or according to a predetermined rule for a predetermined or adaptively variable period using transmitting means of transmitting means different from the first audio transcoding and transmitting means; and C) a selection means for selecting a compression ratio for the encoding of the first to Nth audio transcoding and transmission means according to an available frequency band of each of the first to Mth transmission lines and transmitting it to the first to Mth transmission lines.

The transcoding and receiving apparatus includes: d) selection means for selecting at least one transmission line from the M transmission lines, and receiving the N pieces of encoded data from the selected transmission line, and extracting the encoded data received without transmission error or loss and selecting audio encoded data from the encoded data in the same frame according to a compression ratio, and outputting the selected data.

In the audio data conversion and transmission system according to the second aspect of the present invention, for an integer N equal to or greater than 2 and an integer M equal to or greater than 1, it includes: a first audio transcoding and transmitting means for inputting compressed packet data and transmitting all the packet data or transmitting a part of the packet data adaptively selected according to the characteristics of the input audio data or according to a predetermined rule using a predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting means for decoding input encoded data packet data and compressing and encoding the data into the data packet data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting means, and transmitting all the obtained data packet data or data packet data adaptively selected according to the characteristics of the input audio data or according to a predetermined rule at a predetermined or adaptively variable period using transmitting means identical to or different from the transmitting means of the first audio transcoding and transmitting means; and C) a selection means for selecting a compression ratio for the encoding of at least one of the first to Nth audio transcoding and transmission means according to the available frequency band of each of the first to Mth transmission lines and transmitting it to the first to Mth transmission lines.

The packet converting and receiving apparatus includes: and a selection means for selecting at least one transmission line from the M transmission lines, receiving the N coded data pieces from the selected transmission line, and selecting a coded data packet received without transmission error or loss from the packet data in the same frame according to a compression ratio, and outputting the selected data.

In the audio data conversion and transmission system according to the third aspect of the present invention, the transcoding and transmission apparatus includes, for N greater than or equal to 2 and M greater than or equal to 1:

d) a first audio transcoding and transmitting means for inputting compressed encoded data, and compressing and transcoding all frames of the audio data or a part of the frames selected according to the characteristics of the audio data or according to a predetermined rule at a compression ratio equal to or higher than that of the input audio data, and transmitting the obtained encoded data using a predetermined transmitting means; e) (N-1) units of second to nth audio transcoding and transmitting means for encoding all frames encoded by the first audio transcoding and transmitting means or a part of frames selected according to the characteristics of input audio data or according to a predetermined rule at a compression ratio equal to or higher than that of the first audio transcoding and transmitting means and transmitting encoded data obtained within a predetermined or adaptively variable period using transmitting means different from the transmitting means of the first audio transcoding and transmitting means; and f) a selection means for selecting a compression ratio for the encoding of at least one of the first to Nth audio transcoding and transmission means according to the available frequency band of each of the first to Mth transmission lines and transmitting it to the first to Mth transmission lines.

The transcoding and receiving apparatus includes: g) and a selection means for selecting at least one transmission line from the M transmission lines, receiving the N encoded data pieces from the selected transmission line, and extracting the encoded data received without transmission error or loss and selecting audio encoded data from the encoded data in the same frame according to a compression ratio, and outputting the selected data.

In the audio data conversion and transmission system according to the fourth aspect of the present invention, for N greater than or equal to 2 and M greater than or equal to 1, the transcoding and transmission apparatus includes:

a) first audio transcoding and transmitting means for decoding input encoded data packet data and compressing and transmitting the encoded data at a compression ratio equal to or higher than that of the input audio data and transmitting the obtained one or more encoded data packet data pieces using predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting means for encoding all packet data encoded by the audio transcoding and transmitting means or packet data adaptively selected according to characteristics of input audio data or according to a predetermined rule into a packet at a compression ratio equal to or higher than that of the first audio transcoding and transmitting means and transmitting the encoded datagram data obtained at a predetermined or adaptively variable period using transmitting means identical to or different from the transmitting means of the first audio transcoding and transmitting means; and c) selecting means for selecting a compression ratio for the encoding of at least one of the first to Nth audio transcoding and transmitting means according to the available frequency band of each of the first to Mth transmission lines and transmitting it to the first to Mth transmission lines.

The transcoding and receiving apparatus includes: d) and a selection means for selecting at least one transmission line from the M transmission lines, receiving the N encoded data pieces from the selected transmission line, and selecting an encoded data packet of the lowest compression ratio from among packet data in the same frame received without transmission error or loss, and outputting the selected data.

In the audio data conversion and transmission system according to the fifth aspect of the present invention, the transcoding and transmission apparatus includes, for N greater than or equal to 2 and M greater than or equal to 1:

a) first audio transcoding and transmitting means for inputting encoded data packet data and transmitting all or part of the frames/packets using predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting means for copying packets of all packet data encoded by the first audio encoding means or packets of packet data selected for self-use according to characteristics of input audio data or according to a predetermined rule, and transmitting the packet data obtained at a predetermined or adaptively variable period of time using transmitting means identical to or different from the transmitting means of the first audio transcoding and transmitting means; and c) transmitting means for transmitting outputs of the first to Nth audio transcoding and transmitting means to the first to Mth transmission lines.

The packet converting and receiving apparatus includes: d) and a selection device for selecting at least one transmission line from the M transmission lines, receiving the N encoded data pieces from the selected transmission line, selecting an encoded data packet received without transmission error or loss from the packet data of the same frame, and outputting the selected data.

In the audio data conversion and transmission system according to the sixth aspect of the present invention, the transcoding and transmission apparatus includes, for N greater than or equal to 2 and M greater than or equal to 1:

a) first audio transcoding and transmitting means for decoding input compressed encoded data and decoding the input encoded data and compressing and encoding the data at a compression ratio equal to or higher than that of the input encoded data and transmitting all frames or frames adaptively selected according to the characteristics of the input audio data or according to a predetermined rule using predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting apparatuses for decoding input encoded data and compressing and transmitting the encoded data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting apparatus, and transmitting all frames of the obtained encoded data or transmitting frames adaptively selected at predetermined or adaptively variable periods according to characteristics of the input audio data or according to a predetermined rule using a transmitting apparatus identical to or different from the transmitting apparatus of the first audio transcoding and transmitting apparatus; and c) a selection means for selecting a compression ratio for encoding of at least one of the first to Nth audio transcoding and transmitting means according to an available frequency band of each of the first to Mth transmission lines and transmitting the selection result to the first to Mth transmission lines.

The transcoding and receiving apparatus includes: d) and a selection means for selecting at least one transmission line from the M transmission lines, receiving the N encoded data pieces from the selected transmission line, and extracting the encoded data received without transmission error or loss and selecting audio encoded data of the lowest compression ratio from the encoded data of the same frame, and outputting the selected data.

In the audio data conversion and transmission system according to the seventh aspect of the present invention, the transcoding and transmission apparatus includes, for an integer N greater than or equal to 2 and an integer M greater than or equal to 1: a) a first audio transcoding and transmitting means for inputting compressed encoded data packet data, and decoding the input encoded data packet data, and compressing and encoding data at a compression ratio equal to or higher than that of the input encoded data, and transmitting all data packets or data packets adaptively selected according to the characteristics of the input audio data or according to a predetermined rule using a predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting apparatuses for decoding input encoded packet data and compressing and encoding the data into the packet data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting apparatus; and transmitting all the obtained packet data or a part of the packet data adaptively selected according to the characteristics of the input audio data or according to a predetermined rule using a transmitting means identical to or different from the transmitting means of the first audio transcoding and transmitting means for a predetermined or adaptively variable period of time; and c) selecting means for selecting a compression ratio for the encoding of at least one of the first to Nth audio transcoding and transmitting means according to the available frequency band of each of the first to Mth transmission lines and transmitting it to the first to Mth transmission lines.

Drawings

Fig. 1 shows an audio data transmission system according to first and second embodiments of the present invention.

Fig. 2 shows the structure of an audio transcoding and transmitting apparatus according to the first and second embodiments of the present invention.

Fig. 3 shows the construction of a transcoding and receiving apparatus according to the first to seventh embodiments of the present invention.

Fig. 4 illustrates an encoded data re-combination method performed by an audio transcoding and receiving apparatus according to a first embodiment of the present invention.

Fig. 5 shows an example of transmitting audio coded data packets according to the first to seventh embodiments of the present invention.

Fig. 6 illustrates an encoded data re-combination method performed by an audio transcoding and receiving apparatus according to a second embodiment of the present invention.

Fig. 7 shows a structure of an audio data transmission system according to a third embodiment of the present invention.

Fig. 8 shows a structure of an audio transcoding and transmitting apparatus according to a third embodiment of the present invention.

Fig. 9 illustrates an encoded data re-combination method performed by an audio transcoding and receiving apparatus according to a third embodiment of the present invention.

Fig. 10 illustrates an encoded data re-combination method performed by an audio transcoding and receiving apparatus according to a fourth embodiment of the present invention.

Fig. 11 shows a configuration of an audio data transcoding and transmitting system according to a fifth embodiment of the present invention.

Fig. 12 shows a structure of an audio transcoding and transmitting apparatus according to a seventh embodiment of the present invention.

Fig. 13 shows the structure of an audio transcoding and transmitting system according to the sixth and seventh embodiments of the present invention.

Fig. 14 shows the structures of audio transcoding and transmitting apparatuses according to sixth and seventh embodiments of the present invention.

Fig. 15 shows an example of a system configuration according to an eighth specific embodiment of the present invention.

Reference numeral 10 denotes a transcoding and transmitting apparatus.

Reference numeral 13 denotes a transmission line.

Reference numeral 20 denotes a transcoding and receiving apparatus.

Reference numeral 30 denotes a decoding apparatus.

Reference numeral 40 denotes an encoding apparatus.

Reference numeral 101 denotes an audio data receiving unit.

Reference numeral 102 denotes a first audio data transcoding and transmitting unit.

Reference numeral 103 denotes a first audio data decoding unit.

Reference numeral 104 denotes a second audio data transcoding and transmitting unit.

Reference numeral 105 denotes a third audio data transcoding and transmitting unit.

Reference numeral 106 denotes an nth audio data transcoding and transmitting unit.

Reference numeral 107 denotes a reception line selection unit.

Reference numeral 100 denotes a transcoding and transmitting apparatus.

Reference numeral 108 denotes a first encoded data receiving unit.

Reference numeral 109 denotes a second encoded data receiving unit.

Reference numeral 110 denotes a third encoded data receiving unit.

Reference numeral 111 denotes an nth coded data receiving unit.

Reference numeral 112 denotes an encoded data recombining unit.

Reference numeral 120 denotes a transcoding and receiving apparatus.

Reference numeral 200 denotes a first audio transcoding and transmitting unit.

Reference numeral 201 denotes a first transmission frame/packet selection unit.

Reference numeral 202 denotes a first error detection code plus frame/packet identification number appending unit.

Reference numeral 203 denotes a decoding unit.

Reference numeral 206 denotes a second compression and encoding unit.

Reference numeral 207 denotes a second encoded data packet generating unit.

Reference numeral 208 denotes a second error detection code plus frame/packet identification number appending unit.

Reference numeral 212 denotes a third compression and encoding unit.

Reference numeral 213 denotes a third coded packet generation unit.

Reference numeral 214 denotes a third error detection code plus frame/packet identification number appending unit.

Reference numeral 220 denotes a second audio data transcoding and transmitting unit.

Reference numeral 230 denotes a third audio transcoding and transmitting unit.

Reference numeral 300 denotes a reception line selection unit.

Reference numeral 301 denotes a first packet receiving buffer.

Reference numeral 302 denotes a second encoded data extracting unit.

Reference numeral 303 denotes a first error/packet loss detection unit.

Reference numeral 304 denotes a second packet receiving buffer.

Reference numeral 305 denotes a second encoded data extracting unit.

Reference numeral 306 denotes a second error/packet loss detection unit.

Reference numeral 307 denotes a third packet receiving buffer.

Reference numeral 308 denotes a third encoded data extracting unit.

Reference numeral 309 denotes a third error/packet loss detection unit.

Reference numeral 310 denotes an encoded data recombining unit.

Reference numeral 320 denotes a first encoded data receiving unit.

Reference numeral 330 denotes a second encoded data receiving unit.

Reference numeral 340 denotes a third encoded data receiving unit.

Reference numeral 501 denotes an audio transcoding apparatus.

Reference numerals 502, 503, 506, and 507 denote delay adding units.

Reference numerals 505 and 509 denote transmission lines.

Reference numeral 510 denotes a transmission line selection unit.

Reference numeral 511 denotes a separation unit.

Reference numeral 512 denotes an audio receiving and decoding apparatus.

Reference numeral 700 denotes a transcoding and transmitting apparatus.

Reference numeral 701 denotes an audio data receiving unit.

Reference numeral 702 denotes an audio data coding unit.

Reference numeral 703 denotes a first audio transcoding and transmitting unit.

Reference numeral 704 denotes a second audio transcoding and transmitting unit.

Reference numeral 705 denotes an nth audio data transcoding and transmitting unit.

Reference numeral 706 denotes a reception line selection unit.

Reference numeral 707 denotes a first encoded data receiving unit.

Reference numeral 708 denotes a second encoded data receiving unit.

Reference numeral 709 denotes an nth coded data receiving unit.

Reference numeral 710 denotes an encoded data recombining unit.

Reference numeral 720 denotes an audio transcoding and receiving apparatus.

Reference numeral 730 denotes a transmission line.

Reference numeral 800 denotes a first audio transcoding and transmitting unit.

Reference numeral 801 denotes a decoding unit.

Reference numeral 804 denotes a first compression and encoding unit.

Reference numeral 805 denotes a first encoded data packet generation unit.

Reference numeral 806 denotes a first error detection code plus frame/packet identification number appending unit.

Reference numeral 810 denotes a second compression and encoding unit.

Reference numeral 811 denotes a second coded packet generation unit.

Reference numeral 812 denotes a second error detection code plus frame/packet identification number appending unit.

Reference numeral 1201 denotes an audio data receiving unit.

Reference numeral 1202 denotes a first audio transcoding and transmitting unit.

Reference numeral 1203 denotes an audio data copying unit.

Reference numeral 1204 denotes a second audio transcoding and transmitting unit.

Reference numeral 1205 denotes an nth audio data transcoding and transmitting unit.

Reference numeral 1206 denotes a reception line selection unit.

Reference numeral 1207 denotes a first encoded data receiving unit.

Reference numeral 1208 denotes a second encoded data receiving unit.

Reference numeral 1209 denotes an nth coded data receiving unit.

Reference numeral 1210 denotes an encoded data recombining unit.

Reference numeral 1300 denotes a first audio transcoding and transmitting unit.

Reference numeral 1301 denotes a first transmission packet selection unit.

Reference numeral 1302 denotes a first error detection code plus frame/packet identification number appending unit.

Reference numeral 1303 denotes a packet replication unit.

Reference numeral 1304 denotes a second transmission packet selection unit.

Reference numeral 1305 denotes a second error detection code plus frame/packet identification number appending unit.

Reference numeral 1310 denotes a second audio transcoding and transmitting unit.

Reference numeral 1401 denotes an audio data receiving unit.

Reference numeral 1402 denotes an audio data decoding unit.

Reference numeral 1403 denotes a first audio transcoding and transmitting unit.

Reference numeral 1404 denotes a second audio transcoding and transmitting unit.

Reference numeral 1405 denotes an nth audio data transcoding and transmitting unit.

Reference numeral 1406 denotes a reception line selection unit.

Reference numeral 1407 denotes a first encoded data receiving unit.

Reference numeral 1408 denotes a second encoded data receiving unit.

Reference numeral 1409 denotes an nth encoded data receiving unit.

Reference numeral 1410 denotes an encoded data recombining unit.

Reference numeral 1500 denotes a first audio transcoding and transmitting unit.

Reference numeral 1501 denotes a decoding unit.

Reference numeral 1502 denotes a first transmission frame/packet encoding unit.

Reference numeral 1503 denotes a first error detection code plus frame/packet identification number appending unit.

Reference numeral 1504 denotes a second transmission frame/packet encoding unit.

Reference numeral 1505 denotes a first error detection code plus frame/packet identification number appending unit.

Reference numeral 1510 denotes a second audio transcoding and transmitting unit.

Detailed Description

Specific embodiments of the present invention will be described below. In a first embodiment of the present invention, a transcoding and transmitting apparatus, for an integer N greater than or equal to 2 and an integer M greater than or equal to 1, comprises: a) first audio transcoding and transmitting means (102 shown in fig. 1) for inputting the compressed encoded data and transmitting the entire frames or partial frames adaptively selected according to the characteristics of the input audio or according to a predetermined rule using predetermined transmitting means; b) (N-1) units (104, 105, and 106 shown in fig. 1) of second to nth audio transcoding and transmitting apparatuses for decoding input encoded data and compressing and transmitting the encoded data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting apparatus, and transmitting all frames of the obtained encoded data or partial frames adaptively selected according to the characteristics of the input audio data or according to a predetermined rule at a predetermined or adaptively variable period using a transmitting apparatus of a transmitting apparatus different from the first audio transcoding and transmitting apparatus; and C) a selection means for selecting a compression ratio for the encoding of at least one of the first to Nth audio transcoding and transmission means according to the available frequency band of each of the first to Mth transmission lines and transmitting it to the first to Mth transmission lines.

The transcoding and receiving apparatus includes: d) selecting means (107 shown in fig. 1) for selecting at least one transmission line from the M transmission lines, and means (112 shown in fig. 1) for receiving the N encoded data pieces from the selected transmission line, and extracting the encoded data received without transmission error or loss and the audio encoded data selected at the lowest compression ratio from the encoded data in the same frame, and outputting the selected data. The processing and functions of each device of the transcoding and transmitting apparatus and the transcoding and receiving apparatus can be realized by a computer executing a program for setting the transcoding and transmitting apparatus and the transcoding and receiving apparatus.

[ specific examples ]

In order to explain in detail the manner of carrying out the invention, a first embodiment of the invention will now be described with reference to the accompanying drawings.

General description of (1.A)

Fig. 1 shows a structure according to a first embodiment of the present invention. As shown in fig. 1, the first embodiment of the present invention includes an audio data transcoding and transmitting apparatus 100, an audio data transcoding and receiving apparatus 120, and a transmission line 130 transmitting encoded data. The integer N represents the number of coded data pieces transmitted by the transcoding and transmitting apparatus, and is equal to or greater than 2. The integer M represents the number of transmission lines 130 for transmitting the N coded data pieces, and is 1 or more.

The transcoding and transmitting apparatus 100 inputs audio data encoded by an audio encoding apparatus (not shown in the drawing) and encodes the input audio data into N encoded data pieces, and transmits the resultant data (e.g., first to nth audio encoded data) to first to mth transmission lines. As shown in FIG. 1, the unit 100 includes first through Nth audio transcoding and transmission units 102 and 106, which transmit data to first through Mth transmission lines.

As shown in fig. 1, the transcoding and transmitting apparatus 100 includes M transcoding and transmitting units 1-M with respect to first to mth transmission lines 130. The transcoding and transmitting units 1-M transmit the encoded data to the first to mth M transmission lines 130.

The transcoding and transmitting unit 1-M includes first to Nth audio transcoding and transmitting units 102, 104 and 106 and outputs first to Nth audio streams. Once the transcoding and transmitting unit 1 receives the audio encoded data, the transcoding and transmitting unit 2-M also inputs the audio encoded data. In other words, they are similar in structure to the transcoding and transmitting unit 1. For simplicity, fig. 1 shows only the structure of the transcoding and transmitting unit 1. Hereinafter, the transcoding and transmitting unit 1 will be explained, and thus, the description of the transcoding and transmitting unit 2-M will be omitted.

The audio data receiving unit 101 of the transcoding and transmitting unit 1 receives the audio encoded data. The audio coded data received by the audio data receiving unit 101 of the transcoding and transmitting unit 1 is also supplied to the transcoding and transmitting unit 2-M.

The first audio transcoding and transmitting unit 102 transmits all or a part of frames of input audio data to the transcoding and receiving apparatus 120.

The input audio data is decoded by the audio data decoding unit 103, and the second audio transcoding and transmitting unit 104 compresses and encodes the output of the audio data decoding unit 103 at a compression ratio equal to or higher than that of the first audio stream using a predetermined method, and transmits the encoded data to the transcoding and receiving apparatus 120.

When N is greater than or equal to 3, the third to nth audio transcoding and transmitting units 105 and 106 encode the output of the audio data decoding unit 103 at a compression ratio equal to or higher than that of the second audio transcoding and transmitting unit 104, and transmit the obtained encoded data to the transcoding and receiving apparatus 120. The first through nth audio streams are transmitted to the first through mth transmission lines 130.

The first through Nth audio data streams of the transcoding and transmitting units 1-M are transmitted to the first through Mth transmission lines 130. The compression ratio of the second to nth audio transcoding and transmitting units 104 and 106 may be selected according to the frequency band available for the audio data in each transmission line 130. Thus, the output of the first audio transcoding and transmitting unit 102 and the outputs of the second to Nth audio transcoding and transmitting units 104 and 106 are output to the first to Mth transmission lines 130, in which the compression rate has been controlled. In this particular embodiment, data may be transmitted according to the state of the transmission line or the role of the transmitter of the audio data.

Instead of providing a plurality of transcoding and transmitting units 1-M, the outputs of the first to nth audio transcoding and transmitting units of one transcoding and transmitting unit 1 may be distributed to the first to mth transmission lines 130. In addition, the output paths of the transcoding and transmitting units 1-M may be switched, and the connection of the first to mth transmission lines 130 may be switched.

In the transcoding and receiving apparatus 120, the receiving line selecting unit 107 selects at least one transmission line from the M transmission lines 130 used for transmitting data by the transcoding and transmitting apparatus 100, and receives and decodes N coded data pieces from the selected transmission line.

As shown in fig. 1, the transcoding and receiving apparatus 120 includes first to nth encoded data receiving units 108 and 111 and an encoded data re-combining unit 112. The encoded data receiving unit receives the encoded data transmitted by the first to nth audio transcoding and transmitting units 102 and 106.

The encoded data recombining unit 112 selects, for example, data having the lowest compression ratio from the maximum N encoded data pieces received without transmission errors or losses by the encoded data receiving unit 108-111, and outputs the selected data.

Therefore, according to the present embodiment, a transcoding and transmitting apparatus that transmits audio data encoded by an audio encoding apparatus (not shown in the drawings) includes a data receiving unit 101 for receiving data from the audio encoding apparatus, and converts the audio data into N encoded data pieces, and transmits each data piece to M transmission lines for a predetermined or adaptively variable period. Second to Nth audio transcoding and transmitting means (second to Nth audio transcoding and transmitting units) 104 and 106 encode the output of the audio data decoding unit 103 at a compression ratio equal to or higher than that of the first compression and encoding method. In the receiver, a reception line selection unit 107 selects a transmission line, and an encoded data recombining unit 112 selects encoded data of the lowest compression ratio and high sound quality among encoded data correctly received in the form of a frame or a packet unit, and decodes the selected data. As will be described in detail below.

(1.B) code conversion and transmission apparatus

Fig. 2 shows a detailed structure of an audio transcoding and transmitting apparatus according to a first embodiment of the present invention. For simplicity, the number of coded data pieces N output by the apparatus is set to 3, and the number of transmission lines M for transmitting coded data is set to 2. In fig. 2, a first audio transcoding transmitting unit 200 corresponds to the first audio transcoding and transmitting unit 102 shown in fig. 1, a second audio transcoding transmitting unit 220 corresponds to the second audio transcoding and transmitting unit 104 shown in fig. 1, a decoding unit 203 corresponds to the first audio data decoding unit 103 shown in fig. 1, and a third audio transcoding transmitting unit 230 corresponds to the third audio transcoding and transmitting unit 105 shown in fig. 1.

In the first audio transcoding and transmitting unit 200, the first transmission frame/packet selecting unit 201 adaptively selects a transmitted frame from the input audio frames according to the characteristics of the input audio data and the state of the transmission line. In the adaptive selection frame, the storage means stores in advance a frame for determining whether to select a frame according to the characteristics of audio data (e.g., parameters of an audio signal affecting the sound quality, presence/absence of sound, etc.) and the state of a transmission line (e.g., a state in which a transmission error occurs, etc.). The first transmission frame/packet selection unit 201 may refer to the rule and dynamically select a frame at any time according to the comparison result with the analysis result (or transmission state) of the audio data. When the transmission frame/packet selection unit according to another specific embodiment described below adaptively (dynamically) selects a frame/packet according to the rule, the frame/packet can be selected with reference to the rule. The rules according to which the frames/packets are selected may be dynamically variable.

The first error detection code plus frame/packet identification number appending unit 202 appends an error detection code and a frame/packet identification number to detect a transmission error and a packet loss in an output encoded data packet in the receiving apparatus, and outputs first audio encoded data.

In fig. 2, in the second audio transcoding transmitting unit 220, the decoding unit 203 decodes input audio encoded data.

The second compression and encoding unit 206 compresses and encodes the decoded data obtained by the decoding unit 203 in a predetermined method.

The second encoded packet generation unit 207 encodes the compressed data obtained by the second compression and encoding unit 206 into a variable bit string, and outputs the resultant data in the form of a predetermined packet unit.

The second error detection code plus frame/packet identification number appending unit 208 appends the error detection code and the frame/packet identification number to detect a transmission error and a packet loss of the encoded packet output by the second encoded packet generation unit 207 in the receiving apparatus, and outputs second audio encoded data.

In the third audio transcoding transmitting unit 230, the third compression encoding unit 212 encodes the audio data obtained by the decoding unit 203 at a compression ratio equal to or higher than that of the second compression and encoding unit 206.

The third encoded data packet generation unit 213 encodes the compressed data obtained by the third compression and encoding unit 212 into a variable bit string, and outputs the encoded data in the form of a predetermined data packet unit.

The third error detection code plus frame/packet identification number appending unit 214 appends the error detection code and the frame/packet identification number to detect a transmission error and a packet loss in the compressed packet output by the third encoded packet generation unit 213 by the receiving apparatus and outputs third audio encoded data, and a predetermined transmitting device transmits data in the packet unit.

In the present embodiment, M is set to 2 and N is set to 3. Accordingly, the first to third audio transcoding and transmitting data are transmitted to each of the two transmission lines.

In the present specific embodiment, the outputted second to nth encoded data and the outputted first encoded data may be separately transmitted for a period of time, or the second to nth encoded data may be multiplexed together with the first encoded data.

A first error detection code plus frame/packet identification number appending unit 202 is provided to append the error detection code and the frame/packet identification number to the first encoded data output by the first transmission frame/packet selection unit 201. However, if the information has been added to the input audio packet data, it may be omitted. The transcoding and receiving apparatus can be used if it can detect a transmission error and a packet loss of the transmission coded packet data in any other method. For example, if there is a mechanism to detect a transmission error in the transmission line of the first encoded packet, it is not necessary to add an error detection code by the first error detection code plus frame/packet identification number appending unit 202. In another example, if information for identifying a frame and a packet is contained in the encoded data output from the first transmission frame/packet selection unit 201, it is also not necessary to append the frame/packet identification number by the first error detection code plus frame/packet identification number appending unit 202.

Similarly, a second error detection code plus frame/packet identification number appending unit 208 is provided to append the error detection code and the frame/packet identification number to the second encoded data. However, any method in which the transcoding and receiving apparatus can detect a transmission error and a packet loss of the transmission encoded data may be used.

Similarly, a third error detection code plus frame/packet identification number appending unit 214 is provided to append an error detection code and a frame/packet identification number to the third encoded data, but any method capable of detecting a transmission error and a packet loss of the encoded data transmitted by the transcoding and receiving apparatus may be used.

In a more preferable practical example of the above-described embodiment, the audio transcoding and transmitting apparatus is connected to an internet communication network, and compresses an input audio signal into encoded data according to, for example, an MPEG-4 Advanced Audio Coding (AAC) system using a microphone or the like, and transmits the input data using a real-time transmission protocol (RTP)/User Datagram Protocol (UDP) and an Internet Protocol (IP).

In fig. 2, the second compression and encoding unit 206 and the third compression and encoding unit 212 perform compression processing using a Modified Discrete Cosine Transform (MDCT) and perform quantization. The third compression encoding unit 212 compresses the data such that the compression ratio of the third encoded data may be equal to or higher than that of the first encoded data in the method of quantizing the MDCT factors using a quantization parameter larger than that of the second compression and encoding unit 206 and the method of adaptively cutting the higher-order MDCT.

The coding unit 203 performs inverse quantization and inverse MDCT transform.

The second coded data packet generating unit 207 codes the quantized MDCT factors and the like output from the second compressing and encoding unit 206 according to the grammar prescribed by the MPEG-4 AAC.

Similarly, the third coded-data-packet generating unit 213 codes the quantized MDCT factors and the like output from the third compressing and encoding unit 212 according to the grammar specified by the MPEG-4 AAC.

The first error-detecting code plus frame/packet identification number appending unit 202, the second error-detecting code plus frame/packet identification number appending unit 208, and the third error-detecting code plus frame/packet identification number appending unit 214 generate a UDP datagram including a checksum (check-sum) for detecting an error, and transmit it to the transcoding and receiving apparatus connected to the internet.

(1.C) code conversion and reception device

Fig. 3 shows a detailed structure of the transcoding and receiving apparatus 120 according to the first embodiment of the present invention shown in fig. 1. In fig. 3, the transcoding and receiving apparatus includes a receiving line selecting unit 300, first to third encoded data receiving units 320 and 340, and an encoded data re-combining unit 310.

The receiving line selecting unit 300 selects a transmission line for the transcoding and receiving apparatus to receive the audio data.

In the first coded data receiving unit 320, the first packet receiving buffer 301 receives the first coded data packet data transmitted by the transcoding and transmitting apparatus. The first encoded data extracting unit 302 extracts audio encoded data from the packet data received by the first packet receiving buffer 301. When the first encoded packet data is transmitted, the first error/packet loss detection unit 303 detects the generated bit error and/or packet loss.

In the second encoded data receiving unit 330, the second packet receiving buffer 304 receives the second encoded packet data transmitted by the transcoding and transmitting apparatus. The second encoded data extraction unit 305 extracts audio encoded data from the packet data received by the second packet reception buffer 304. The second error/packet loss detection unit 306 detects a bit error and/or a packet loss generated when the second encoded data packet data is transmitted.

In the third encoded data receiving unit 340, the third packet receiving buffer 307 receives the third encoded data packet data transmitted by the transcoding and transmitting apparatus. The third encoded data extraction unit 308 extracts audio encoded data from the packet data received by the third packet reception buffer 307. The third error/packet loss detection unit 309 detects a bit error and/or a packet loss generated when the third encoded data packet data is transmitted.

The coded data recombining unit 310 recombines two coded data pieces transmitted by the transcoding and transmitting apparatus into one coded data piece according to the result of the detection of errors and/or packet losses by the first error/packet loss detecting unit 303, the second error/packet loss detecting unit 306, and the third error/packet loss detecting unit 309.

The encoded data recombining step performed by the encoded data recombining unit 310 in the present embodiment will be described below with reference to a flowchart shown in fig. 4. In the series of steps shown in fig. 4, the encoded data re-combination process for the nth frame is performed over a given integer N.

In step S401, when all encoded data in the nth frame will arrive at the first packet reception buffer 301 and the second packet reception buffer 304, control is delayed until a time obtained by adding the maximum delay time, and then control proceeds to step S402.

In step S402, it is determined whether there is any packet loss or bit error in the nth frame data in the first packet reception buffer 301, based on the detection results of the first error/packet loss detection unit 303 detecting errors and packet loss. If the first packet reception buffer 301 has received all the data of the nth frame and no data error has been detected, control proceeds to step S403. Otherwise, control passes to step S404.

When control proceeds to S403, the encoded data of the nth frame output by the first encoded data extraction unit 302 is output, thereby terminating the encoded data re-combination process.

When control proceeds to step S404, it is determined whether there is a packet loss or a bit error in the nth frame data according to the detection results of the errors and packet losses by the second error/packet loss detection unit 306. When the second packet reception buffer 304 receives all the data of the nth frame and any data error is not detected, then control proceeds to step S405. Otherwise, control passes to step S406.

When the control proceeds to step S406, it is determined whether there is a packet loss or a bit error in the nth frame data according to the detection result of the error and/or packet loss by the third error/packet loss detection unit 309. When the third packet reception buffer 307 receives all the data of the nth frame and any data error is not detected, then control proceeds to step S407. Otherwise, control passes to step S403.

In step S407, the encoded data in the nth frame output by the third encoded data extraction unit 308 as encoded data to be decoded is output, thereby terminating the encoded data re-combination processing.

The above is the encoded data re-combining step performed by the encoded data re-combining unit 310.

In this particular embodiment, any method of detecting a transmission error and/or a packet loss error in the first encoded data performed by the first error/packet loss detection unit 303 may be used. For example, according to this embodiment, detection can be performed using an error detection code and the number of frames/packets added by the transcoding and transmitting apparatus. When an error detection function is provided for the transmission line of the encoded data, the detection result thereof can also be used. When information indicating the encoded frame is included in the encoded data, the information included in the encoded data may be used.

Similarly, any method of detecting transmission errors and/or data packet losses in the second encoded data performed by the second error/data packet loss detection unit 306 may be used.

Also, any method of detecting a transmission error and/or a packet loss in the third encoded data, which is performed by the third error/packet loss detection unit 309, may also be used.

In the encoded data re-combining step performed by the encoded data re-combining unit 310, when the packet transmission delay is suppressed within a predetermined range, the method of waiting for reception of the encoded data of the nth frame in step S401 may be replaced by any method as long as data loss can be detected.

In the encoded data re-combining step performed by the encoded data re-combining unit 310, in step S406, when a transmission error or a packet loss is detected in the encoded data received in the third received packet buffer, that is, when a transmission error or a packet loss has occurred in all of the first to third encoded data, the encoded data re-combining unit 310 may take any other measures.

In this specific embodiment, control proceeds to step S403, and first encoded data, which is encoded data to be decoded, is output. However, it is possible to stop outputting the nth frame, and take the audio data in the (N-1) th frame that was just output before as the nth frame, and so on, for example.

In a preferred example of the embodiment of the present invention, the transcoding and receiving apparatus is connected to an internet communication network, and receives the transmitted packet data from the transcoding and transmitting apparatus at another point connected to the internet communication network using RTP/UDP/IP protocol, and converts audio encoded data contained in the received UDP datagram and outputs the result to the decoder. The audio encoded data conforms to the MPEG-4AAC system. The first error/packet loss detection unit 303, the second error/packet loss detection unit 306, and the third error/packet loss detection unit 309 can detect a transmission error by calculating a checksum included in the UDP datagram.

Further, since the transcoding and receiving apparatus only has to decode three pieces of received encoded data, it is possible to suppress an increase in necessary computational complexity as compared with the conventional audio encoding apparatus.

(1, D) Transmission method of data packet data

According to the present invention, the first to second coded packet data may be transmitted from the transcoding and transmitting apparatus to the transcoding and receiving apparatus in any method. However, in order to improve the effect of the present invention, a method that can minimize the relationship between a bit error and a packet loss occurring in the first encoded packet data obtained by encoding the same frame and a bit error and a packet loss occurring in the second encoded packet data is preferable. Fig. 5 shows a preferred manner of transmitting encoded data packet data.

In fig. 5, reference numeral 501 denotes the audio transcoding apparatus which has been described with reference to fig. 1 and 2. Delay appending units 502 and 503 append predetermined or adaptively variable delay times to the second and third encoded data packet data output by the audio transcoding device 501. The multiplexing unit 504 multiplexes the first encoded data output by the audio transcoding device 501 and the second encoded data output by the delay adding unit 502, and multiplexes the third encoded data output by the delay adding unit 503, and transmits the result to the transmission line. The transmission line 505 transmits the data multiplexed by the delay appending unit 503 from the transmitting apparatus to the receiving apparatus. Similarly, multiplexer 508 and transmission line 509 transmit data to the second transmission line.

In the delay adding units 502 and 503, delay times added to the second and third encoded data depend on a maximum burst time of a bit error and a packet loss occurring in the transmission line 505. The delay value depends on factors to be considered, such as bit rate, amount of buffering, etc. Therefore, even when a burst error occurs in the transmission line 505, the probability that the first to third encoded data are affected by the error can be small. Therefore, it is possible to alleviate a serious deterioration in sound quality due to the loss of frame-encoded data. The long burst time due to the packet loss depends on actual measurement or the like, and the delay set by the delay adding unit is set according to the buffer amount of the receiving apparatus and the transmission rate (bit rate) of the transmission line.

Similarly, the delay times applied to the second and third encoded data by the delay adding units 506 and 507 depend on the maximum burst time of a bit error and a packet loss occurring in the transmission line 509. Therefore, even if a burst error occurs in the transmission line 509, the first to third encoded data obtained by encoding data in the same frame have a small probability of being affected by the error. Therefore, it is possible to suppress occurrence of serious deterioration in sound quality due to loss of frame-encoded data. The delay adding unit, or the delay adding unit and the multiplexing unit may be provided in the audio transcoding apparatus 501.

(1, E) advantages

According to the first embodiment, the audio transcoding and transmitting apparatus converts the same audio data into N (N ═ 3 in this example) coded data pieces, and transmits the resulting data at a predetermined or adaptively variable period. The first audio transcoding and transmitting unit outputs an input audio data frame adaptively selected according to characteristics of audio data or according to a predetermined rule. The second audio transcoding and transmitting unit decodes the input audio data and outputs decoded data encoded at a compression ratio equal to or higher than that of the input data. The third audio transcoding and transmitting unit encodes the frame encoded by the second audio transcoding and transmitting unit.

The transcoding and receiving apparatus receives data from at least one of the M element transmission lines, selects encoded data of a low compression ratio and a high sound quality frame by frame from the encoded data correctly received, and outputs the selected data.

As a result, even when an unreliable transmission line in which a high burst transmission error and packet loss often occur is used, the probability of erroneously transmitting N pieces of encoded data can be reduced, and occurrence of severe deterioration in decoded sound quality can be prevented after transmission.

Further, by increasing the compression ratio of the second to third encoded data, it is possible to suppress the increase of the passband during transmission of the encoded data.

In addition, the first to third encoded data can be transmitted to a plurality of transmission lines having different frequency bands according to available frequency bands, and the influence of transmission line errors can be mitigated.

According to this embodiment, although the transcoding and transmitting apparatus and the transcoding and receiving apparatus are used in combination, they may be used independently. For the multiplex transmission, the order of the packets of the first to nth transcoded data may be scrambled by an interleaving method or the like.

[ second mode for carrying out the invention ]

In a second embodiment of the present invention, for an integer N equal to or greater than 2 and an integer M equal to or greater than 1, the transcoding and transmitting apparatus includes: a) first audio transcoding and transmitting means for inputting compressed packet data and transmitting all the packets or transmitting a part of the packets adaptively selected using predetermined transmitting means according to the characteristics of the input audio data or according to a predetermined rule; b) (N-1) units of second to nth audio transcoding and transmitting means for decoding input encoded packet data and compressing and encoding data into the packet data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting means, and transmitting all the obtained packet data or packet data adaptively selected at a predetermined or adaptively variable period according to characteristics of the input audio data or according to a predetermined rule using transmitting means identical to or different from the transmitting means of the first audio transcoding and transmitting means; and C) a selection means for selecting a compression ratio for encoding of at least one of the first to Nth audio transcoding and transmission means and transmitting it to the first to Mth transmission lines.

The packet converting and receiving apparatus includes: and a selection means for selecting at least one transmission line from the M transmission lines, receiving the N coded data pieces from the selected transmission line, and selecting a coded data packet received without transmission error or loss from the packet data in the same frame according to a compression ratio, and outputting the selected data. The processing and functions of each device of the transcoding and transmitting apparatus and the transcoding and receiving apparatus can be realized by a computer executing a program for setting the transcoding and transmitting apparatus and the transcoding and receiving apparatus.

[ second embodiment ]

To describe in detail the second mode of carrying out the invention, a second embodiment of the invention will be described below.

(2.A) overview

The construction and operation of this embodiment are substantially the same as the first embodiment. As shown in fig. 1, the embodiment of the present invention includes an audio data transcoding and transmitting apparatus 100, a transcoding and receiving apparatus 120, and a transmission line 130 transmitting encoded data. The integer N represents the number of coded data pieces transmitted by the transcoding and transmitting apparatus, and is equal to or greater than 2. The integer M represents the number of transmission lines 130 for transmitting the N coded data pieces, and is 1 or more.

The structure of the transcoding and transmitting apparatus 100 is basically the same as that of the transcoding and transmitting apparatus according to the first invention, but the operation of each unit constituting the apparatus is somewhat different. The different points thereof will be explained below.

The audio data in the input frame encoded by the first audio transcoding and transmitting unit (first audio encoding frame 1 transmitting unit) 102 is set with one or more packet data, and each packet data piece is encoded compressed data. The first audio stream transcoding and receiving apparatus 120 transmits all or a portion of the packets of the input audio data.

The second audio transcoding and transmitting unit (second audio encoding frame 1 transmitting unit) 104 decodes input audio data, compresses and encodes the decoded audio data at a compression ratio equal to or higher than that of the first audio stream, and transmits the encoded data to the transcoding and receiving apparatus 120.

The third to nth audio transcoding and transmitting units 105 and 106 encode the decoded audio data from the audio decoding unit 103 at a compression ratio equal to or higher than that of the second audio transcoding and transmitting unit and transmit the obtained encoded packet data to the transcoding and receiving apparatus. The operation of this embodiment is substantially the same as that of the first embodiment except that the above-described operation is dealt with. In the second embodiment, the compression ratio of the second to nth audio transcoding and transmitting units 104 and 106 may be selected according to the frequency band available for transmitting audio data in each transmission line 130. The outputs of the first through Nth audio transcoding and transmission units 102, 104 and 106 are output to the first through Mth transmission lines 130. In this particular embodiment, data may be transmitted based on the state of the transmission line or the action of the audio data transmitter.

The structure of the transcoding and receiving apparatus 120 is basically the same as that of the transcoding and receiving apparatus according to the first embodiment, but the operation of each unit constituting the apparatus is somewhat different. The different points thereof will be explained below.

The encoded data recombining unit 112 selects a packet of the lowest compression ratio from up to N pieces of encoded data packet data slices including compressed data in the same area of the same frame received without transmission error or loss by the same first to nth encoded data receiving units as the first embodiment. Data is selected from the packet units transmitted by the transcoding and transmitting device. The operation of this embodiment is substantially the same as that of the first embodiment except for the above-described operation.

(2.B) code conversion and transmission apparatus

The operation and structure of the transcoding and transmitting apparatus according to the present invention are basically the same as the transcoding and transmitting apparatus according to the first embodiment shown in fig. 2. Only the operations of the first encoded packet selecting unit 201, the second encoded packet generating unit 207, the third encoded packet generating unit 213, the first error detection code plus frame/packet identification number appending unit 202, the second error detection code plus frame/packet identification number appending unit 208, and the third error detection code plus frame/packet identification number appending unit 214 are different. The different points thereof will be explained below.

The first error-detecting code plus frame/packet identification number appending unit 202, the second error-detecting code plus frame/packet identification number appending unit 208, and the third error-detecting code plus frame/packet identification number appending unit 214 operate so that the same packet identification number can be assigned to encoded packet data in the same frame. The operation of the processing unit is the same as that of the first embodiment except for the above-described operation.

(2.C) code conversion and reception device

The structure and operation of the audio transcoding and receiving apparatus according to this embodiment are basically the same as those of the audio transcoding and receiving apparatus according to the first embodiment, and only the operation of the encoded data recombining unit 310 shown in fig. 3 is different. The different points thereof will be explained below.

The encoded data recombining step performed by the encoded data recombining unit 310 in the present embodiment will be described below with reference to a flowchart shown in fig. 6. In the series of steps shown in fig. 6, the encoded data re-combination process for the nth frame is performed over a given integer N.

In step S601, when all encoded data in the nth frame will arrive at the first packet reception buffer 301, the second packet reception buffer 304, and the third packet reception buffer 307, control is delayed until a time obtained by adding the maximum delay time, and then control proceeds to step S602.

In step S602, a variable a for storing the number of packets stores the minimum value of the number of packets of the nth frame, and a variable b stores the maximum value of the number of packets of the nth frame.

In step S603, the variable i for the number of stored packets is replaced with the variable value, and the process is repeated from step S604.

In step S604, it is determined whether or not the ith packet is present and whether or not there is a bit error in the first packet reception buffer 301, based on the detection results of the first error/packet loss detection unit 303 detecting an error and a packet loss. When the ith packet in the nth frame is received in the first packet reception buffer 301 and the data has no error, control proceeds to S605. Otherwise, control proceeds to step S606.

When control proceeds to step S605, the encoded data in the nth frame output by the first encoded data extraction unit 302 is output as encoded data to be decoded, and then control proceeds to step S610.

When the control proceeds to step S606, it is determined whether the ith packet and the second packet reception buffer 304 have a bit error according to the detection results of the second error/packet loss detection unit 306 detecting an error and a packet loss. When the second packet reception buffer 304 receives the ith packet of the nth frame and no data error is detected, control proceeds to step S607. Otherwise, control passes to step S608.

In step S607, the encoded data in the nth frame output by the second encoded data extraction unit 305 is output as encoded data to be decoded, and then control proceeds to step S610.

When the control proceeds to step S608, it is determined whether or not the ith packet is present and whether or not there is a bit error in the third packet reception buffer 307, based on the detection results of the third error/packet loss detection unit 309 detecting an error and a packet loss. When the third packet reception buffer 307 receives the ith packet in the nth frame and no data error is detected, control proceeds to S609. Otherwise, control proceeds to step S610.

In step S610, 1 is added to the variable i. In step S611, it is determined whether the value of the variable i exceeds the value of the variable b. If not, the process is repeated from step S604.

In step S610, when the variable i exceeds the variable b, a series of repeated processes ends, thereby terminating the N-th frame encoded data re-combination process.

In the above, the operation of the encoded data recombining unit 310 according to the present embodiment has been described. The method of waiting for reception of the encoded data of the nth frame in step S601 of the encoded data re-combining step performed by the encoded data re-combining unit 310 according to the present embodiment may be replaced by any method of detecting a packet loss using a transmission delay kept in a predetermined range.

(2.D) advantages

According to the second embodiment, the audio transcoding and transmitting apparatus encodes the same audio data into N (N ═ 3 in this example) encoded data pieces, and transmits the resulting data at a predetermined or adaptively variable period.

The second to third audio transcoding and transmitting apparatuses encode a region including the decoded audio data from the audio decoding unit.

The transcoding and receiving apparatus selects encoded data of a low compression ratio and high sound quality from the correctly received encoded data in the packet unit and then decodes the data.

As a result, even when an unreliable transmission line in which a high burst transmission error and packet loss frequently occur is used, the probability of erroneously transmitting 3 coded data pieces can be reduced, and occurrence of severe deterioration in decoded sound quality can be prevented after transmission.

In addition, the first to third encoded data can be transmitted to a plurality of transmission lines having different frequency bands according to available frequency bands, and the influence of transmission line errors can be mitigated. Since the transcoding and receiving apparatus only needs to decode one of the three received encoded data, it is possible to suppress an increase in necessary computational complexity compared to the conventional audio decoding apparatus.

According to this embodiment, although the transcoding and transmitting apparatus and the transcoding and receiving apparatus are used in combination, they may be used independently.

[ third mode for carrying out the invention ]

In a third embodiment of the present invention, for an integer N equal to or greater than 2 and an integer M equal to or greater than 1, the transcoding and transmitting device comprises: a) first audio transcoding and transmitting means for inputting the compressed encoded data, compressing and transcoding all frames of the decoded audio data or part of the frames selected according to the characteristics of the input audio data or according to a predetermined rule at a compression ratio equal to or higher than the compression ratio of the input audio data, and transmitting the obtained encoded data using predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting means for encoding all decoded frames output from the audio data decoding unit or partial frames selected according to the characteristics of input audio data or according to a predetermined rule at a compression ratio equal to or higher than that of the first audio transcoding and transmitting means and transmitting the obtained encoded data at a predetermined or adaptive variable period using transmitting means different from the transmitting means of the first audio transcoding and transmitting means; and c) selecting means for selecting a compression ratio for the encoding of at least one of the first to Nth audio transcoding and transmitting means according to the available frequency band of each of the first to Mth transmission lines and transmitting it to the first to Mth transmission lines.

The transcoding and receiving apparatus includes: d) and a selection means for selecting at least one transmission line from the M transmission lines, receiving the N encoded data pieces from the selected transmission line, and extracting the encoded data received without transmission error or loss and the audio encoded data selected at the lowest compression ratio from the encoded data of the same frame, and outputting the selected data. The processing and functions of each device of the transcoding and transmitting apparatus and the transcoding and receiving apparatus can be realized by a computer executing a program for setting the transcoding and transmitting apparatus and the transcoding and receiving apparatus.

[ third embodiment ]

In order to explain in detail the third mode of carrying out the invention, a third embodiment of the invention will be explained below with reference to the drawings.

(3.A) overview

Fig. 7 shows a structure according to a third embodiment of the present invention. As shown in fig. 7, the embodiment of the present invention includes a transcoding and transmitting apparatus for audio data (hereinafter, referred to as "audio transcoding and transmitting apparatus") 700, a transcoding and receiving apparatus (hereinafter, referred to as "audio transcoding and receiving apparatus") 720, and a transmission line 730 for transmitting encoded data. The integer N represents the number of coded data transmitted by the transcoding and transmitting apparatus 700, and is assumed to be 2 or more. The integer M represents the number of transmission lines used to transmit the N coded data pieces and is assumed to be 1 or more.

The audio transcoding and transmitting apparatus 700 decodes input audio data, compresses and encodes the obtained audio data at a compression ratio equal to or higher than that of the input data, and transmits the transcoded data to the audio transcoding and receiving apparatus 720. Input audio data is encoded into N encoded data pieces and transmitted as first to Nth audio encoded data to first to Mth transmission lines. As shown in fig. 7, the apparatus includes transcoding units 1-N, each of which includes N units (first to nth audio transcoding and transmitting units) 703, 704, 705 of first to nth audio transcoding and transmitting units.

The audio data receiving unit 701 receives audio data.

The audio data decoding unit 702 decodes input audio encoded data.

The first audio transcoding and transmitting unit 703 compresses and encodes the frame input to the transcoding and transmitting apparatus in a predetermined method, and transmits the obtained encoded data to the audio transcoding and receiving apparatus 720.

The second to nth audio transcoding and transmitting units 704 and 705 encode all or part of the decoded frames from the audio data decoding unit 702 at a compression ratio equal to or higher than that of the first audio transcoding and transmitting unit 703 and transmit the obtained encoded data to the transcoding and receiving apparatus 720. The first through nth audio streams are transmitted to the first through mth transmission lines 730. Each transmission line 730 can be controlled by selecting a compression ratio for the encoding of the first to nth audio transcoding and transmitting units 703 and 705 according to an available frequency band for transmitting audio data. The outputs of the controlled coding compression ratios of the first to nth audio transcoding and transmitting units 703 and 705 are output to the first to mth transmission lines, and data can be transmitted according to the state of the transmission lines or the effect of audio data transmission.

In the audio transcoding and receiving apparatus 720, the receiving line selecting unit 706 selects at least one transmission line from M transmission lines for the audio transcoding and transmitting apparatus to transmit data, receives N coded data pieces from the selected transmission line, and decodes the data.

As shown in fig. 7, the audio transcoding and receiving apparatus 720 includes first to nth encoded data receiving units 707 and 709 and an encoded data re-combining unit 710. The encoded data receiving unit 707-.

The encoded data recombining unit 710 selects data having the lowest compression ratio from the maximum N encoded data pieces received without transmission errors or losses by the encoded data receiving unit 707-709, and outputs the selected data.

(3.B) code conversion and transmission apparatus

Fig. 8 shows a detailed structure of an audio transcoding and transmitting apparatus according to a third embodiment of the present invention. For simplicity, the number N of coded data pieces output by the apparatus is assumed to be 2, and the number M of transmission lines for transmitting coded data is assumed to be 2. The apparatus corresponds to the structure shown in fig. 7 including a first audio transcoding and transmitting unit 703 and a second audio transcoding and transmitting unit 704.

In fig. 8, a first audio transcoding and transmitting unit 800 includes a coding unit 801 for coding input audio data; a first compressing and encoding unit 804 for compressing and encoding the data; a first encoded data packet generation unit 805 for encoding the compressed data obtained by the first compression and encoding unit 804 into a bit string of variable length and outputting the result in the form of a predetermined data packet unit; and a first error detection code frame/packet identification number appending unit 806 for appending an error detection code and a frame/packet identification number so as to detect a transmission error and a packet loss of the encoded packet data output by the first encoded packet generation unit 805 by the receiving apparatus. The first audio coded data packet is transmitted in a packet unit by a predetermined transmission device.

In fig. 8, the second audio transcoding and transmitting unit 820 (corresponding to the second audio transcoding and transmitting unit 704) includes a second compressing and encoding unit 810 for encoding data at a compression ratio equal to or higher than that of the first compressing and encoding unit 804; a second encoded data packet generation unit 811 for encoding the compressed data obtained by the second compression and encoding unit 810 into a bit string of variable length and outputting the result in the form of a predetermined data packet unit; and a second error detection code plus frame/packet identification number appending unit 812 for appending an error detection code and a frame/packet identification number so as to detect a transmission error and a packet loss of the compressed packet data output by the second encoded packet generation unit 811 by the receiving apparatus. The second audio coded data packet is transmitted in a packet unit by a predetermined transmission device.

In the present embodiment, M and N are assumed to be 2. Thus, the first and second audio transcoding and transmission packets are transmitted onto the two transmission lines.

In the present embodiment, the first error detection code plus frame/packet identification number appending unit 806 appends an error detection code and a frame/packet identification number to the first encoded packet data output by the first encoded packet generation unit 805. However, if the transcoding and receiving apparatus can detect a transmission error and a packet loss of the transmission coded packet data in any other method, they can be used. For example, when there is a mechanism to detect a transmission error in the transmission line of the first encoded packet, then it is not necessary to add an error detection code by the first error detection code plus frame/packet identification number appending unit 806. In another example, if there is information identifying a frame and a packet in the encoded data output from the first encoded data packet generation unit 805, it is not necessary to add a frame/packet identification number by the first error detection code frame/packet identification number addition unit 806.

Similarly, the second error detection code plus frame/packet identification number appending unit 812 adds an error detection code and a frame/packet identification number to the second encoded packet data. However, if the transcoding and receiving apparatus can detect a transmission error and a packet loss of the transmission coded packet data in any other method, they can be used.

The more preferable example of the present embodiment described above is the same as the preferable example of the first embodiment according to the present invention.

(3.C) code conversion and reception device

The audio transcoding and receiving apparatus (720 shown in fig. 7) according to the third embodiment of the present invention has the same structure as that shown in fig. 3. In fig. 3, the number M of transmission lines is 3, and M is 2 in the present embodiment. Therefore, the third encoded data receiving unit 340 (refer to fig. 3) of the transcoding and receiving apparatus does not exist in the current embodiment. Further, since M is 2, the operation steps of the encoded data recombining unit 310 are different from those shown in fig. 3.

The operation method performed by the encoded data recombining unit 310 in the present embodiment will be described below with reference to a flowchart shown in fig. 9. In the series of steps shown in fig. 9, the encoded data re-combination process for the nth frame is performed over a given integer N.

In step S901, when all encoded data in the nth frame will reach the first packet reception buffer 301 and the second packet reception buffer 304 (refer to fig. 3), control is delayed until a time obtained by adding the maximum delay time, and then control proceeds to step S902.

In step S902, it is determined whether there is any packet loss or bit error in the nth frame data in the first packet reception buffer 301, based on the detection results of the first error/packet loss detection unit 303 detecting errors and packet loss. If the first packet reception buffer 301 has received all the data of the nth frame and no data error is detected, control proceeds to step S903. Otherwise, control proceeds to step S904.

When control proceeds to step S903, the encoded data of the nth frame output by the first encoded data extraction unit 302 is sent to a variable length decoding unit (not shown in fig. 3; corresponding to the decoding device shown in fig. 15, for example) as encoded data to be decoded, thereby terminating the encoded data recombining process.

When control proceeds to step S904, it is determined whether there is a packet loss or a bit error in the nth frame data according to the detection results of the errors and packet losses by the second error/packet loss detection unit 306. When the second packet reception buffer 304 receives all the data of the nth frame and no data error is detected, control proceeds to step S905. Otherwise, control proceeds to step S903.

In step S905, the encoded data of the nth frame output from the second encoded data extraction unit 305 is transmitted to a variable length decoding unit (not shown in fig. 3; corresponding to, for example, the decoding apparatus shown in fig. 15) as encoded data to be decoded, thereby terminating the encoded data recombining process.

The operations of the other units according to the present specific embodiment and preferred example are the same as those according to the first embodiment.

(3.D) advantages

According to the third embodiment described above, the audio transcoding and transmitting apparatus decodes input audio data and encodes the same audio data into two coded data pieces and transmits them at predetermined or adaptively variable periods.

The second audio transcoding and transmitting device encodes the decoded audio data from the audio data decoding unit.

The transcoding and receiving apparatus selects encoded data of a low compression ratio and high sound quality from the encoded data correctly received in frame units and then outputs the selected data. As a result, even when an unreliable transmission line in which a high burst transmission error and packet loss frequently occur is used, the probability of erroneously transmitting 2 coded data pieces can be reduced, and occurrence of severe deterioration in decoded sound quality can be prevented after transmission.

Further, by increasing the compression ratio of the second encoded data, it is possible to suppress the increase of the passband during transmission of the second encoded data. In addition, the first to second encoded data can be transmitted to a plurality of transmission lines having different frequency bands according to the state of the transmission line and the function of the audio transmitter or the audio receiver, and the influence of transmission line errors can be mitigated.

In addition, since the transcoding and receiving apparatus can decode at least one of the two received decoded data pieces, it is possible to suppress an increase in necessary computational complexity as compared with the conventional audio decoding apparatus.

According to this embodiment, although the transcoding and transmitting apparatus and the transcoding and receiving apparatus are used in combination, they may be used independently. The first to nth transcoded data may be arranged using interleaving.

[ fourth mode for carrying out the invention ]

In a fourth embodiment of the present invention, for an integer N greater than or equal to 2 and an integer M greater than or equal to 1, the transcoding and transmitting apparatus comprises: a) first audio transcoding and transmitting means for decoding input encoded data packet data, compressing and transmitting the encoded data at a compression ratio equal to or higher than that of the input audio data, and transmitting the obtained one or more encoded data packet data pieces using predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting means for encoding all packet data from the audio data decoding unit or part of the packet data adaptively selected according to the characteristics of the input audio data or according to a predetermined rule into a packet including the same region as the packet data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting the obtained encoded packet data using transmitting means identical to or different from the transmitting means of the first audio transcoding and transmitting means for a predetermined or adaptively variable period; and c) selecting means for selecting a compression ratio for the encoding of at least one of the first to Nth audio transcoding and transmitting means according to the available frequency band of each of the first to Mth transmission lines and transmitting it to the first to Mth transmission lines.

The transcoding and receiving apparatus includes: d) and a selection means for selecting at least one transmission line from the M transmission lines, receiving the N encoded data pieces from the selected transmission line, and selecting an encoded data packet of the lowest compression ratio from among packet data in the same frame received without transmission error or loss, and outputting the selected data. The processing and functions of each device of the above-described transcoding and transmitting apparatus and transcoding and receiving apparatus can be realized by a computer executing a program that sets the above-described transcoding and transmitting apparatus and transcoding and receiving apparatus.

[ fourth embodiment ]

To explain in detail the fourth mode of carrying out the invention, a fourth embodiment of the invention will be explained below with reference to the drawings.

(4.A) overview

As shown in fig. 7, the structure and operation according to this embodiment are substantially the same as those according to the third embodiment, and include an audio transcoding and transmitting apparatus 700, a transcoding and receiving apparatus 720, and a transmission line 730 for transmitting encoded data. The integer N represents the number of coded data pieces transmitted by the transcoding and transmitting apparatus, and is equal to or greater than 2. The integer M represents the number of transmission lines 130 for transmitting the N coded data pieces, and is 1 or more.

The structure of the audio transcoding and transmitting apparatus is basically the same as that of the audio transcoding and transmitting apparatus according to the third embodiment, but the operation of each unit constituting the apparatus is somewhat different. The apparatus decodes input audio data, and compresses and encodes the obtained audio data at a compression ratio equal to or higher than that of the input audio data, and transmits the transcoded data to the audio transcoding and receiving apparatus 720. The encoded data of the input frame encoded by the first audio transcoding and transmitting unit 703 is set by one or more pieces of packet data. The second to nth audio transcoding and transmitting units 704 and 705 encode all or a part of the decoded packets from the audio data decoding unit 702 at a compression ratio equal to or higher than that of the first audio transcoding and transmitting unit 703 and transmit the obtained encoded packet data to the audio transcoding and receiving apparatus. The operation of this embodiment is substantially the same as that of the third embodiment except for the above-described operation.

The structure of the audio transcoding and receiving apparatus is basically the same as that of the audio transcoding and receiving apparatus according to the third embodiment, but the operation of each unit constituting the apparatus is somewhat different. These differences will be described below. The encoded data recombining unit 710 selects a packet of the lowest compression ratio as encoded data to be decoded from up to N pieces of encoded data packet data slices including compressed data in the same area of the same frame and encoded data received by the first to N-th encoded data receiving units 707, 708, and 709 without occurrence of a transmission error or data loss as in the third embodiment. This selection is performed on each packet data transmitted by the transcoding and transmitting device. The operation of this embodiment is substantially the same as that of the first embodiment except for the above-described operation. In this embodiment, the compression ratio for the first to nth audio transcoding and transmitting units 703 and 705 is selected according to the frequency band available for transmitting audio data in each transmission line 730. The outputs of the first to nth audio transcoding and transmitting units 703 and 705 are output to the first to mth transmission lines 730, and data can be transmitted according to the state of the transmission lines or the action of the audio data transmitter.

(4.B) code conversion and transmission apparatus

The structure and operation of the audio data transcoding and transmitting apparatus according to this embodiment are substantially the same as those of the audio data transcoding and transmitting apparatus according to the third embodiment shown in fig. 8, and only the operations of the following units shown in fig. 8 are different: a first encoded packet generating unit 805, a second encoded packet generating unit 811, a first error detection code plus frame/packet identification number appending unit 806, and a second error detection code plus frame/packet identification number appending unit 812. The different points thereof will be explained below.

That is, in the present embodiment, the first error-detecting code plus frame/packet identification number appending unit 806 and the second error-detecting code plus frame/packet identification number appending unit 812 operate so that the same packet identification number can be added to the encoded packet data in the same frame. The operation of this embodiment is substantially the same as that of the third embodiment except for the operation of the above-described units.

A more preferred practical example of this embodiment is similar to the preferred example according to the second embodiment.

(4.C) code conversion and reception device

The operation and structure of the audio transcoding and receiving apparatus according to the current embodiment are substantially the same as those of the audio transcoding and receiving apparatus according to the second embodiment shown in fig. 3. In fig. 3, the number M of transmission lines is 3, and M is 2 in the present embodiment. Therefore, the third encoded data receiving unit does not exist in the present specific embodiment. Further, since M is 2, the operation steps of the encoded data recombining unit 310 are different.

The operation method performed by the encoded data recombining unit 310 in the present embodiment will be described below with reference to a flowchart shown in fig. 10. In a series of steps shown in fig. 10, the encoded data re-combination process for the nth frame is performed over a given integer N.

In step S1001, when all encoded data in the nth frame will reach the first packet reception buffer 301 and the second packet reception buffer 304, control is delayed until a time obtained by adding the maximum delay time, and then control proceeds to step S1002.

In step S1002, the variable a storing the number of packets stores the number of packets of the nth frame, and the variable b stores the maximum value of the number of packets of the nth frame.

In step S1003, the variable i storing the number of packets is replaced with the value of the variable a, and the process is repeated from step S1004.

In step S1004, it is determined whether or not the ith packet of the nth frame is present and whether or not there is a bit error in the first packet reception buffer 301, based on the detection results of the first error/packet loss detection unit 303 detecting an error and a packet loss. When the ith packet in the nth frame is received in the first packet reception buffer 301 and it is determined in step S1004 that the data is not in error, control proceeds to S1005. Otherwise, control proceeds to step S1006.

When control proceeds to step S1005, the encoded data of the nth frame output from the first encoded data extraction unit 302 is transmitted to a variable length decoding unit (not shown in the figure; corresponding to, for example, the decoding device shown in fig. 15) as encoded data to be decoded, and then control proceeds to step S1008.

When the control proceeds to step S1006, it is determined whether or not the ith packet of the nth frame is present and whether or not there is a bit error in the second packet reception buffer 304, based on the detection results of the second error/packet loss detection unit 306 detecting an error and a packet loss.

When the second packet reception buffer 304 receives the ith packet of the nth frame and no data error is detected in step S1006, control proceeds to step S1007. Otherwise, control passes to step S1008.

In step S1007, the encoded data of the nth frame output from the second encoded data extraction unit 305 is sent to a variable length decoding unit (not shown in the figure; corresponding to, for example, a decoding device shown in fig. 15) as encoded data to be decoded, and then control proceeds to step S1008.

In step S1008, 1 is added to the variable i. In step S1009, it is determined whether the variable i exceeds the variable b. If not, the process is repeated from step S1004. When the variable i exceeds the variable b, a series of repeated processes is ended, thereby terminating the N-th frame encoded data recombining process.

The operation and preferred example of each unit other than the above-described unit according to the present specific example are the same as those according to the third specific embodiment.

(4.D) advantages

According to the fourth embodiment described above, the audio transcoding and transmitting apparatus decodes input audio data and encodes the same audio data into two coded data pieces and transmits them at predetermined or adaptively variable periods.

The second encoding transmission means encodes the decoded audio data from the audio data decoding unit. The transcoding and receiving apparatus selects encoded data of a low compression ratio and high sound quality from the correctly received encoded data in the packet unit and then outputs the selected data. As a result, even when an unreliable transmission line in which a high burst transmission error and packet loss frequently occur is used, the probability of erroneously transmitting 2 coded data pieces can be reduced, and occurrence of severe deterioration in decoded sound quality can be prevented after transmission.

According to this embodiment, although the transcoding and transmitting apparatus and the transcoding and receiving apparatus are used in combination, they may be used independently. The first to nth code conversion data may be interleaved in a time-division manner.

[ fifth mode for carrying out the invention ]

In a fifth embodiment of the present invention, for an integer N greater than or equal to 2 and an integer M greater than or equal to 1, the transcoding and transmitting apparatus comprises: a) a first audio transcoding and transmitting means for inputting encoded data packet data and transmitting all or part of the data packets using a predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting means for copying packets of received packet data or packet data adaptively selected according to characteristics of input audio data or according to a predetermined rule and transmitting the obtained packet data using transmitting means identical to or different from the transmitting means of the first audio transcoding and transmitting means for a predetermined or adaptively variable period; and c) transmitting means for transmitting outputs of the first to Nth audio transcoding and transmitting means to the first to Mth transmission lines.

The packet converting and receiving apparatus includes: d) and a selection device for selecting at least one transmission line from the M transmission lines, receiving the N encoded data pieces from the selected transmission line, selecting an encoded data packet received without transmission error or loss from the packet data, and outputting the selected data. The processing and functions of each device of the above-described transcoding and transmitting apparatus and transcoding and receiving apparatus can be realized by a computer executing a program constituting the above-described transcoding and transmitting apparatus and transcoding and receiving apparatus.

[ fifth embodiment ]

To explain in detail the fifth mode of carrying out the invention, a fifth embodiment of the invention will be explained below with reference to the drawings.

(5.A) overview

Fig. 11 shows a fifth embodiment of the present invention. As shown in fig. 11, this embodiment of the present invention includes an audio data transcoding and transmitting apparatus 1200, a transcoding and receiving apparatus 1220, and a transmission line 1230 for transmitting encoded data. The integer N represents the number of coded data pieces to be transmitted by the transcoding and transmitting apparatus, and is assumed to be 2 or more. The integer M represents the number of transmission lines 130 for transmitting the N coded data pieces, and is 1 or more. The transcoding and transmitting apparatus inputs audio packet data, selects all data or a part of the data, and transmits the data to first to Mth transmission lines.

As shown in fig. 11, the transcoding and transmitting apparatus 1200 has N units of first to nth audio transcoding and transmitting units 1202, 1204 and 1205 for transmitting data to M units of first to mth transmission lines 1230. The audio data receiving unit 1201 receives audio packet data. The first audio transcoding and transmitting unit 1202 transmits all or a part of the packets of the input audio packet data to the audio transcoding and receiving apparatus 1220.

The audio data copying unit 1203 copies all the packet data that has been received or copies a part of the packet data adaptively selected according to the characteristics of the input audio data or according to a predetermined rule, and outputs them to the second to nth audio transcoding transmitting units 1204, 1205.

The second audio transcoding and transmitting units 1204 and 1205 partially transmit the copied packet to the audio transcoding and receiving apparatus by selecting the same number of pieces of packet data or different number of pieces of packet data of the first audio packet data. The first through nth audio streams are transmitted to first through mth transmission lines.

In the audio transcoding and receiving apparatus 1220, the reception line selecting unit 1206 selects at least one transmission line from M transmission lines to which the audio transcoding and transmitting apparatus transmits data, receives N coded data pieces from the selected transmission line, and decodes the data.

As shown in FIG. 12, the transcoding and receiving apparatus 1200 includes first to Nth encoded data receiving units 1207-.

The encoded data recombining unit 1210 selects data from the maximum N encoded data pieces received without transmission error or loss by the encoded data receiving unit 1207-1209, and outputs the selected data.

(5.B) code conversion and transmission apparatus

Fig. 12 shows a detailed structure of an audio transcoding and transmitting apparatus according to a fifth embodiment of the present invention. For simplicity, the number N of coded data pieces output by the apparatus is set to 2, and the number M of transmission lines for transmitting coded data is set to 2. In fig. 12, the first audio transcoding transmitting unit 1300 includes: a first transmission packet selection unit 1301 for adaptively selecting a packet from the input audio packet data according to the characteristics of the audio signal and the state of the transmission line; and a first error detection code plus frame/packet identification number appending unit 1302 for appending an error detection code and a frame/packet identification number for detecting a transmission error and a packet loss of the outputted encoded data packet data and outputting the first encoded data.

In fig. 12, the second audio transcoding and transmitting unit 1310 includes a packet copying unit 1303 for copying the input audio coded packet data, a second packet selecting unit 1304, and a second error detection code plus frame/packet identification number appending unit 1305, wherein the second packet selecting unit 1304 selects a packet to be adaptively transmitted to a partial packet adaptively selected according to the characteristics of input audio data or according to a predetermined rule from among the reproduced audio packet data by an identification number equal to or different from the identification number selected by the first audio code and transmitting unit 1300, and the second error detection code adding frame/packet identification number appending unit 1305 is used to append an error detection code and a packet identification number used by the receiving apparatus for detecting a transmission error and a packet loss of the encoded data packet data output by the second packet selecting unit 1304. The unit outputs second encoded data.

In the present embodiment, M is set to 2, and N is also set to 2. Thus, the first and second audio transcoding and transmission data are transmitted to two transmission lines, respectively.

The operation of the other processing units is substantially the same as that of the fourth embodiment except for the operation of the above units. More preferred specific examples of the above-described specific embodiment are similar to the preferred examples according to the second specific embodiment.

The structure and operation of the audio transcoding and receiving apparatus are the same as according to the fourth embodiment.

(5.C) advantages

According to the fifth embodiment described above, the audio transcoding and transmitting apparatus converts the same audio data into two coded data pieces and transmits them for a predetermined or adaptively variable period. The first audio transcoding and transmitting unit outputs an adaptive selection of input audio data according to the characteristics of the input audio data or according to a predetermined rule, and transmits the data. The second audio transcoding and transmitting unit copies all packet data or copies a part of data adaptively selected according to the characteristics of input audio data or according to a predetermined rule, selects data having an identification number identical to or different from that of the input data, and then transmits the selected data.

The transcoding and receiving apparatus selects data in which no error or loss occurs from among coded data in a unit of a correctly received packet, selects high-quality data from among data received on two transmission lines, and outputs the selected data. As a result, even when an unreliable transmission line in which a high burst transmission error and packet loss frequently occur is used, the probability of erroneously transmitting 2 coded data pieces can be reduced, and occurrence of severe deterioration in decoded sound quality can be prevented after transmission.

Further, by reducing the number of choices of the second encoded data, it is possible to suppress the increase of the passband during transmission of the second encoded data. In addition, the first to second encoded data can be transmitted to a plurality of transmission lines having different frequency bands according to the state of the transmission line and the function of the audio transmitter or the audio receiver, and the influence of transmission line errors can be mitigated.

In addition, since the transcoding and receiving apparatus can decode at least one of the two received decoded data pieces, it is possible to suppress an increase in necessary computational complexity compared to the conventional audio decoding apparatus.

[ sixth mode for carrying out the invention ]

According to a sixth embodiment of the present invention, for an integer N greater than or equal to 2 and an integer M greater than or equal to 1, the transcoding and transmitting apparatus comprises: a) first audio transcoding and transmitting means for inputting compressed encoded data, and decoding the input encoded data, and compressing and encoding the data at a compression ratio equal to or higher than that of the input encoded data, and transmitting all frames or frames adaptively selected according to the characteristics of the input audio data or according to a predetermined rule using predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting means for decoding input encoded data and compressing and transmitting the encoded data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting means, and transmitting all frames of the obtained encoded data or transmitting partial frames adaptively selected according to the characteristics of the input audio data or according to a predetermined rule using transmitting means different from the transmitting means of the first audio transcoding and transmitting means; and c) a selection means for selecting a compression ratio for encoding of at least one of the first to Nth audio transcoding and transmitting means according to an available frequency band of each of the first to Mth transmission lines and transmitting the selection result to the first to Mth transmission lines.

The transcoding and receiving apparatus includes: d) and a selection means for selecting at least one transmission line from the M transmission lines, receiving the N encoded data pieces from the selected transmission line, and extracting the encoded data received without transmission error or loss and the audio encoded data selected at the lowest compression ratio from the encoded data of the same frame, and outputting the selected data. The processing and functions of each device of the above-described transcoding and transmitting apparatus and transcoding and receiving apparatus can be realized by a computer executing a program that sets the above-described transcoding and transmitting apparatus and transcoding and receiving apparatus.

[ sixth embodiment ]

To explain in detail the manner of carrying out the invention, a sixth embodiment of the invention will now be described with reference to the accompanying drawings.

Fig. 13 shows a sixth embodiment of the present invention. As shown in fig. 13, the embodiment of the present invention includes an audio data transcoding and transmitting apparatus 1400, a transcoding and receiving apparatus 1420, and a transmission line 1430 for transmitting encoded data. The integer N represents the number of coded data pieces to be transmitted by the transcoding and transmitting apparatus, and is assumed to be 2 or more. The integer M represents the number of transmission lines 130 for transmitting the N coded data pieces, and is 1 or more.

The audio transcoding and transmitting apparatus 1400 decodes the input encoded data and compresses and encodes the obtained audio data at a compression ratio equal to or higher than that of the input data using a predetermined method, and transmits it to the transcoding and receiving apparatus 1420. Input audio data is encoded into N encoded data pieces and transmitted as first to Nth audio encoded data to first to Mth transmission lines.

As shown in fig. 13, the audio transcoding and transmitting apparatus includes N units of first to nth audio transcoding and transmitting units (first to nth audio transcoding and transmitting units) 1403, 1404 and 1405.

The audio data receiving unit 1401 receives audio data.

The audio data decoding unit 1402 decodes input audio encoded data.

The first audio transcoding and transmitting unit 1403 compresses and encodes the output of the coding unit 1402 in a predetermined method, and transmits the obtained encoded data to the audio transcoding and receiving apparatus.

The second to nth audio transcoding and transmitting units 1404 and 1405 encode data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting unit 1403 and transmit the obtained encoded data to the audio transcoding and receiving apparatus. The first through nth audio streams are transmitted to first through mth transmission lines.

In the present embodiment, the compression ratio may be selected for the encoding of the first through nth audio transcoding transmission units 1403 and 1405 based on the frequency band available for each transmission line 1430 to transmit audio data. The outputs of the first through nth audio transcoding and transmitting units 1403 and 1405 are output to the first through mth transmission lines 1430, whereby data is transmitted according to the state of the transmission lines and the action of the audio data transmitter.

In the audio transcoding and receiving apparatus 1420, the receiving line selecting unit 1406 selects at least one transmission line from the M transmission lines used by the audio transcoding and transmitting apparatus to transmit data, receives N coded data pieces from the selected transmission line, and decodes the received data.

As shown in fig. 13, the audio transcoding and receiving apparatus 1420 includes first to nth encoded data receiving units 1407 and 1409 and an encoded data recombining unit 1410. The encoded data receiving unit receives the encoded data transmitted by the first to nth audio transcoding and transmitting units 1403 and 1405 of the transcoding transmitting apparatus 1400.

The encoded data recombining unit 1410 selects data having the lowest compression ratio from the maximum N encoded data pieces received without transmission errors or losses by the encoded data receiving unit 1407-1409, and outputs the selected data.

(6.B) code conversion and transmission apparatus

Fig. 14 shows a detailed structure of an audio transcoding and transmitting apparatus according to a sixth embodiment of the present invention. For simplicity, the number N of coded data pieces output by the apparatus is set to 2, and the number M of transmission lines for transmitting coded data is set to 2. In fig. 14, the apparatus includes a decoding unit 1501 for decoding input audio data, and the first audio transcoding and transmitting unit 1500 includes a first transmission frame/packet encoding unit 1502 for encoding the decoded audio data at a compression ratio equal to or higher than that of the input data and a first error detection code plus frame/packet identification number appending unit 1503 for detecting a transmission error and a packet loss in the encoded data output by the first transmission frame/packet encoding unit 1502 for the receiving apparatus and outputting the first audio encoded data, and transmits the data by a predetermined transmitting device.

In fig. 14, the second audio transcoding and transmitting unit 1510 includes a second transmission frame/packet encoding unit 1504 for encoding data at a compression rate equal to or higher than that of the first audio transcoding and transmitting unit 1500 and outputting the encoded data; a second error detection code plus frame/packet identification number appending unit 1505 for appending an error detection code and a frame/packet identification number used by the receiving apparatus for detecting a transmission error and a packet loss of the encoded data packet output by the second transmission frame/packet encoding unit 1504. And the second audio encoded data is output and transmitted by a predetermined transmission means.

In the present embodiment, M is set to 2, and N is also set to 2. Thus, the first and second audio transcoding and transmission data are transmitted to each of the two transmission lines, respectively. The operation of the other processing units is substantially the same as that of the third embodiment except for the operation of the above units.

More preferred specific examples of the above-described specific embodiment are similar to the preferred examples according to the first specific embodiment.

The structure and operation of the audio transcoding and receiving apparatus are the same as those according to the third embodiment.

(6.C) advantages

According to the third embodiment described above, the audio transcoding and transmitting apparatus decodes input audio data and encodes the same audio data into two encoded data pieces, and transmits the encoded data at a predetermined or adaptively variable period.

The transcoding and receiving apparatus selects encoded data of a low compression ratio and high sound quality from the encoded data in a correctly received frame unit and then outputs the selected data. As a result, even when an unreliable transmission line in which a high burst transmission error and packet loss frequently occur is used, the probability of erroneously transmitting 2 coded data pieces can be reduced, and occurrence of severe deterioration in decoded sound quality can be prevented after transmission.

Further, by increasing the compression ratio of the second encoded data, it is possible to suppress the increase of the passband during transmission of the second encoded data.

In addition, the first to second encoded data can be transmitted to a plurality of transmission lines having different frequency bands according to the state of the transmission line and the function of the audio transmitter or the audio receiver, and the influence of transmission line errors can be mitigated. In addition, since the transcoding and receiving apparatus can decode at least one of the two received decoded data pieces, it is possible to suppress an increase in necessary computational complexity compared to the conventional audio decoding apparatus.

[ seventh mode for carrying out the invention ]

In a seventh embodiment of the present invention, for an integer N greater than or equal to 2 and an integer M greater than or equal to 1, the transcoding and transmitting apparatus comprises: a) a first audio transcoding and transmitting means for inputting compressed encoded data packet data, and decoding the input encoded data packet data, and compressing and encoding data at a compression ratio equal to or higher than that of the input encoded data, and transmitting all data packets or partial data packets adaptively selected according to the characteristics of the input audio data or according to a predetermined rule using a predetermined transmitting means; b) (N-1) units of second to nth audio transcoding and transmitting means for decoding input encoded data packet data and compressing and encoding the data into the data packet data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting means, and transmitting all the obtained data packet data or part of the data packet data adaptively selected according to the characteristics of the input audio data or according to a predetermined rule for a predetermined or adaptively variable period of time using transmitting means identical to or different from the transmitting means of the first audio transcoding and transmitting means; and c) selecting means for selecting a compression ratio for the encoding of at least one of the first to Nth audio transcoding and transmitting means according to the available frequency band of each of the first to Mth transmission lines and transmitting it to the first to Mth transmission lines.

The transcoding and receiving apparatus includes: d) and a selection means for selecting at least one transmission line from the M transmission lines, receiving the N encoded data pieces from the selected transmission line, and selecting encoded data packet data of the lowest compression ratio from among data packets received without transmission error or loss, and outputting the selected data. The processing and functions of each device of the above-described transcoding and transmitting apparatus and transcoding and receiving apparatus can be realized by a computer executing a program that sets the above-described transcoding and transmitting apparatus and transcoding and receiving apparatus.

[ seventh embodiment ]

To describe in detail the seventh mode for carrying out the invention, a seventh embodiment of the invention will be described below with reference to the accompanying drawings.

(7.A) overview

The structure and operation of the present embodiment are substantially the same as those of the sixth embodiment. As shown in fig. 13, the embodiment of the present invention includes an audio data transcoding and transmitting apparatus 1400, a transcoding and receiving apparatus 1420, and a transmission line 1430 for transmitting encoded data. The integer N represents the number of coded data pieces to be transmitted by the transcoding and transmitting apparatus, and is assumed to be 2 or more. The integer M represents the number of transmission lines 130 for transmitting the N coded data pieces, and is 1 or more.

The structure of the audio transcoding and transmitting apparatus is basically the same as that of the audio transcoding and transmitting apparatus according to the sixth embodiment, but the operation of each unit constituting the apparatus is somewhat different. The different points thereof will be explained below.

Input audio data is decoded, and encoded data is compressed and encoded using a predetermined method at a compression ratio equal to or higher than that of the input audio data, and the transcoded data is transmitted to an audio transcoding and receiving apparatus.

The encoded data of the input frame encoded by the audio image transcoding processing unit is composed of one or more pieces of packet data.

The second to Nth audio transcoding and transmitting units encode all or part of the data packets from the audio data decoding unit at a compression ratio equal to or higher than that of the first audio transcoding and transmitting unit and transmit the obtained encoded data packet data to the audio transcoding and receiving apparatus. The operation of this embodiment is substantially the same as that of the sixth embodiment except as described above.

The structure of the audio transcoding and receiving apparatus is also basically the same as that of the audio transcoding and receiving apparatus according to the sixth embodiment, but the operation of each unit constituting the apparatus is somewhat different. The different points thereof will be explained below.

In fig. 13, the coded data re-combining unit 1410 selects a packet as the lowest compression ratio to be decoded from up to N pieces of coded data packet data pieces including compressed data of the same frame received by the first to nth coded data receiving units without transmission errors or losses, and transmits the selection result in the form of a packet unit by the transcoding and transmitting apparatus as in the sixth embodiment. The operation of this embodiment is substantially the same as that of the sixth embodiment except for the above-described operation.

(7.B) code conversion and transmission apparatus

The structure and operation of the audio data transcoding and transmitting apparatus according to this embodiment are substantially the same as those of the audio data transcoding and transmitting apparatus according to the sixth embodiment shown in fig. 14, and only the operations of the following units shown in fig. 14 are different: a first transmission frame/packet encoding unit 1502, a second transmission frame/packet encoding unit 1504, a first error detection code plus frame/packet identification number appending unit 1503, and a second error detection code plus frame/packet identification number appending unit 1505. The different points thereof will be explained below.

In the audio data transcoding and transmitting apparatus according to the current embodiment, the first transmission frame/packet encoding unit 1502 and the second transmission frame/packet encoding unit 1504 generate packet data such that the frame of the encoded packet data generated by the first transmission frame/packet encoding unit 1502 can be matched with the frame of the encoded packet data generated by the second transmission frame/packet encoding unit 1504. The operation of the remaining units is similar to that according to the sixth embodiment, except for the operation of the above-described units.

A more preferred practical example of this embodiment is similar to the preferred example according to the second embodiment. The structure and operation of the audio transcoding and receiving apparatus are the same as those of the audio transcoding and receiving apparatus according to the fourth embodiment.

(7.C) advantages

According to the seventh embodiment described above, the audio transcoding and transmitting apparatus decodes input audio data and encodes the same audio data into two coded data pieces and transmits them at predetermined or adaptively variable periods. The second encoding transmission device encodes the packet encoded by the first encoding transmission device.

The transcoding and receiving apparatus selects encoded data of a low compression ratio and high sound quality from the correctly received encoded data in the packet unit and then outputs the selected data. As a result, even when an unreliable transmission line in which a high burst transmission error and packet loss frequently occur is used, the probability of erroneously transmitting 2 coded data pieces can be reduced, and occurrence of severe deterioration in decoded sound quality can be prevented after transmission.

[ eighth mode for carrying out the invention ]

Another specific embodiment of the present invention will be described below. Fig. 15 shows a system configuration according to an eighth specific embodiment of the present invention. In fig. 15, the system includes an encoding apparatus 40 for outputting encoded data, an audio data transcoding and transmitting apparatus 10, transcoding and receiving apparatuses 201 to 20K for a plurality of (K) audio data, and a receiver connected to the transcoding and receiving apparatusesReceiving apparatus 20₁To 20_KA plurality of (K) decoding devices 30₁To 30_K. The encoding device 40 forms a kind of information providing a source for distributing encoded data, and a well-known server device is used as the device. As in the first to ninth embodiments described above, the transcoding and transmitting apparatus 10 according to the present invention includes a transcoding and transmitting apparatus (e.g., 100 shown in fig. 1).

As in the first to seventh embodiments described above, the plurality of audio data transcoding and receiving apparatuses 20 according to the present invention includes a transcoding and receiving apparatus (e.g., 120 shown in fig. 1). The decoding apparatus 30 is an apparatus (decoder) for decoding and displaying the video data from the transcoding and receiving apparatus 20. An off-the-shelf product may be used.

In the example shown in fig. 15, each of the transcoding and receiving apparatuses is assigned one of the transcoding and transmitting apparatus 10 and the transcoding and receiving apparatus 20₁To 20_KA transmission line 13 that transmits information therebetween. That is, M is assumed to be 1 among the M transmission lines 130 of the example of fig. 1, and a plurality of transcoding and receiving apparatuses are provided in fig. 1. The transcoding and transmitting device 10 has N audio transcoding and transmitting units (not shown in the figure) and outputs N pieces of data stream as described above for each of the embodiments.

As a more practical example of the present embodiment of the present invention, the transcoding and transmitting apparatus 10 is connected to an internet communication network (or intranet), and inputs the encoded data transmitted by the encoding apparatus 40 using UDP/IP protocol. For example, the processing of the audio transcoding and transmitting unit (not shown in the figure) of the transcoding and transmitting device 10 is performed corresponding to the real-time transport protocol (RTP). The transcoding and receiving device 20 may be a client connected to an internet communication network, for example.

In this embodiment, when the transmission line is in a wireless form, the transcoding (N data streams) output by the transcoding and transmitting device 10 is output through the UDP/IP protocol and physical layer and transmitted to the destination transcoding and receiving device 20 through a base station in the mobile packet communication system network, through a router, a gateway, and the like. In the transcoding and receiving apparatus 20, the data code converted by the transcoding and transmitting apparatus 10 between the encoding apparatus 40 and the decoding apparatus 30 is recombined into the encoded data corresponding to the original encoding by the encoding apparatus 40, and the obtained data is output. The decoding apparatus 30 outputs the audio data to an audio output apparatus (not shown in the figure) by performing decoding processing corresponding to the encoding by the encoding apparatus 40. The decoding device (decoder) 30 connected to the transcoding and receiving device 20 may be provided as a terminal incorporated into the transcoding and receiving device 20, or may be provided to one terminal (personal computer) connected to the terminal constituting the transcoding and receiving device for communication, or the like.

In this embodiment, the transcoding and receiving apparatus 20 outputs a control signal (request signal) to the transcoding and transmitting apparatus 10. The transcoding and transmitting apparatus 10 receives the control signal and transmits the encoded data to the transcoding and receiving apparatus 20. Fig. 15 shows that the control signal is different from the coded stream output by the transcoding and transmitting device 10.

Using the control signal transmitted from the transcoding and receiving apparatus 20 to the transcoding and transmitting apparatus 10, system information about the transcoding and receiving apparatus 20, such as an IP address, device information, a coding system available to the transcoding apparatus 30 (e.g., ITU-T recommended h.261 or h.263, visual MPEG-4 recommended by ISO/IEC) may be provided through the transcoding and transmitting apparatus 10 so that the transcoding and transmitting apparatus 10 receiving the request signal may perform transcoding applied to the transcoding and receiving apparatus 20 and the transcoding apparatus 30. It is clear that according to the invention the transmission line can be a cable.

In the configuration shown in fig. 15, the multiplexer may multiplex the coded data streams output from the transcoding and transmitting device 10 to the plurality (N) lines of the transmission line 13, respectively, at different periods of time provided by the delay adding unit shown in fig. 5, or cross the N data streams by the multiplexing unit and rearrange the transmission order by interleaving, thereby transmitting the multiplexed output through the transmission line at intervals. The delay adding unit and the multiplexer shown in fig. 5 can be provided in the transcoding and transmitting apparatus 10. In this case, the transcoding and receiving apparatus 20 includes the separating unit 511 shown in fig. 5, and multiplexed transmission packets received by the transmission line selected by the receiving transmission line selecting unit are separated into packets of each stream, and the encoded data is extracted and recombined. In this embodiment, the coded data of the coding apparatus 40 as the information provider is received by the transcoding and transmitting apparatus 10. The transcoding and transmitting apparatus 10 performs conversion for preventing data loss and data error and transmits data to the transcoding and receiving apparatus 20, so that encoded data can be efficiently transmitted through the transmission line 13. The decoding apparatus 30 performs decoding corresponding to the encoding method of the encoding apparatus 40.

While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. Those skilled in the art will recognize that changes or modifications can be made to the specific embodiments without departing from the scope and spirit of the invention.

Industrial applicability

As described above, according to the present invention, even when an unreliable transmission line in which a high burst transmission error and a packet loss frequently occur is used, the probability of erroneously transmitting N pieces of encoded data can be reduced, and occurrence of serious deterioration in the sound quality of decoding can be prevented after transmission. The reason will be explained below.

That is, according to the present invention, the transcoding and transmitting apparatus includes first to nth audio transcoding and transmitting devices on first to mth transmission lines with respect to an integer N equal to or greater than 2 and an integer M equal to or greater than 1, and transmits all or part of frames, or packets, of audio data, or after decoding, compresses and encodes the audio data into coded data pieces and transmits them at predetermined or adaptively variable periods. The second to Nth audio transcoding and transmitting apparatuses encode the input frame, and the transcoding and receiving apparatus selects encoded data of the lowest compression ratio and high sound quality from among encoded data in the form of frame or packet units correctly received through the M transmission lines, and then decodes the selected encoded data.

According to the present invention, the state of the transmission line or the transmission state according to the action of the audio data transmitter can be reflected in the transmission.

The reason is that, according to the present invention, by using the first to mth transmission lines, the compression ratios of the first to nth audio transcoding and transmitting apparatuses can be selected according to the frequency band available for transmitting audio data in each transmission line.

Further, according to the present invention, since the process of transmitting a plurality of encoded data can be reduced, the transmission rate is improved.

According to the present invention, since the second to nth audio transcoding and transmitting apparatuses encode data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting apparatus, transmission of the encoded data by the second to nth audio transcoding and transmitting apparatuses can be performed only on frames encoded by the first audio transcoding and transmitting apparatus.

Furthermore, according to the present invention, the increase in computational complexity required for the receiver can be reduced.

The reason is that the transcoding and transmitting apparatus generates encoded data including the same frame, and the transcoding and receiving apparatus selects and decodes only a single data piece in the form of a frame or a packet unit from among the received encoded data pieces. Therefore, the transcoding and receiving apparatus does not have to decode the received plurality of coded data slices.

Claims

1. An audio data transcoding and transmitting apparatus, comprising:

(a) the first audio code conversion and transmission device is used for inputting compressed audio coding data and outputting all input audio coding data or partial frames of the input audio coding data;

(b) second to nth audio transcoding and transmitting means for decoding all or part of input audio coded data, and encoding data obtained by decoding the data, and outputting all or part of the obtained frames of the coded data, where N is a predetermined integer equal to or greater than 2; and

(c) transmitting means for transmitting the outputs of the first to Nth audio transcoding and transmitting means onto first to Mth transmission lines, wherein M is an integer equal to or greater than 1.

2. An audio data transcoding and transmitting apparatus, comprising:

(a) a first audio transcoding and transmitting means for inputting the compressed audio coded packet data and outputting all or a part of the data packets of the input audio coded packet data;

(b) second to Nth audio transcoding and transmitting means for decoding input audio coded packet data, and coding data obtained by decoding the data, and outputting all or part of the obtained packet data, wherein N is a predetermined integer equal to or greater than 2; and

(c) transmitting means for transmitting the outputs of the first to Nth audio transcoding and transmitting means onto first to Mth transmission lines, wherein M is a predetermined integer equal to or greater than 1.

3. An audio data transcoding and transmitting apparatus, comprising:

(a) a first audio transcoding and transmitting means for inputting compressed audio coded data, and coding data obtained by decoding all or part of frames of the input audio coded data, and outputting the obtained coded data;

(b) second to nth audio transcoding and transmitting means for encoding all or part of frames obtained by decoding input audio encoded data, where N is a predetermined integer equal to or greater than 2, and outputting the obtained encoded data; and

4. An audio data transcoding and transmitting apparatus, comprising:

(a) a first audio transcoding and transmitting means for inputting compressed audio coded packet data, and encoding data obtained by decoding the input audio coded packet data, and outputting the obtained coded packet data;

(b) second to nth audio transcoding and transmitting means for encoding all or part of packet data obtained by decoding input audio coded packet data, where N is a predetermined integer equal to or greater than 2, and outputting the obtained coded packet data; and

5. An audio data transcoding and transmitting apparatus, comprising:

(a) a first audio transcoding and transmitting means for inputting the compressed audio coded data packet data and outputting all or part of the input audio coded data packet data:

(b) second to nth audio transcoding and transmitting means for copying all packet data or a part of packet data of the audio coded packet data input to the first audio transcoding and transmitting means and outputting the packet data obtained by the copying, N being a predetermined integer greater than or equal to 2; and

6. An audio data transcoding and transmitting apparatus, comprising:

(a) a first audio transcoding and transmitting means for inputting compressed audio coded data, and decoding the input audio coded data, and encoding data obtained by the decoding, and outputting all or part of the obtained frames;

(b) second to Nth audio transcoding and transmitting means for decoding input audio coded data, and coding data obtained by the decoding, and outputting all frames or partial frames of the obtained coded data, wherein N is a predetermined integer equal to or greater than 2; and

7. An audio data transcoding and transmitting apparatus, comprising:

(a) a first audio transcoding and transmitting means for inputting compressed audio coded packet data, decoding the input coded packet data, encoding the packet data obtained by the decoding, and outputting all or a part of the packets obtained by the encoding;

(b) second to nth audio transcoding and transmitting means for decoding input coded packet data, and coding the packet data obtained by the decoding, and outputting all or part of the packet data obtained by the coding, wherein N is a predetermined integer greater than or equal to 2; and

8. An audio data transcoding and transmitting apparatus, comprising:

(a) a first audio transcoding and transmitting means for inputting compressed audio coded data and outputting all or part of the frames of the input audio coded data;

(b) second to nth audio transcoding and transmitting means for decoding input audio coded data, and coding data obtained by the decoding and outputting all or part of frames of the coded data obtained by the coding, N being a predetermined integer equal to or greater than 2; and

(c) transmitting means for transmitting outputs of the first to Nth audio transcoding and transmitting means to first to Mth transmission lines, M being a predetermined integer equal to or greater than 1.

9. Audio data transcoding and transmitting device according to one of claims 1, 3, 6 and 8, characterized in that:

at least one of the first through nth audio transcoding and transmitting devices selects a partial frame according to characteristics of audio data or according to a predetermined rule.

10. Audio data transcoding and transmitting device according to one of claims 2, 4, 5 and 7, characterized in that:

at least one of the first through nth audio transcoding and transmitting devices selects a data packet according to characteristics of audio data or according to a predetermined rule.

11. Audio data transcoding and transmitting device according to one of claims 3, 4, 6 and 7, characterized in that:

the first audio transcoding and transmitting apparatus decodes input encoded data, and encodes data obtained by the decoding by compressing the data at a compression ratio equal to or higher than that of the input encoded data.

12. Audio data transcoding and transmitting device according to claim 1 or 2, characterized in that:

the second to Nth audio transcoding and transmitting apparatuses decode input encoded data and encode data obtained by the decoding by compressing the data at a compression ratio equal to or higher than that of the input encoded data.

13. Audio data transcoding and transmitting device according to one of claims 3, 4, 6 and 7, characterized in that:

the second to Nth audio transcoding and transmitting means decodes input encoded data and encodes data obtained by the decoding by compressing the data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting means.

14. Audio data transcoding and sending apparatus according to one of claims 1 to 8, characterized in that:

the apparatus also includes means for controlling each output of the second through nth audio transcoding and transmitting means and the output of the first audio transcoding and transmitting means using different times.

15. Audio data transcoding and sending apparatus according to one of claims 1 to 8, characterized in that:

the apparatus further comprises: a selection means for selecting a compression ratio for encoding of at least one of the first to Nth audio transcoding and transmitting means according to available frequency bands of the first to Mth transmission lines and transmitting the selected compression ratio to the first to Mth transmission lines.

16. Audio data transcoding and sending apparatus according to one of claims 1 to 8, characterized in that:

the second through nth audio transcoding and transmitting devices transmit data using a transmitting device the same as or different from the first audio transcoding and transmitting device for a predetermined or adaptively variable period of time.

17. Audio data transcoding and sending apparatus according to one of claims 1 to 8, characterized in that:

the apparatus further comprises first to Mth audio transcoding and transmitting units each comprising said first to Nth audio transcoding and transmitting means, wherein M is a predetermined integer greater than 1; and

the outputs of the first to Mth audio transcoding and transmitting units are transmitted to the first to Mth transmission lines, respectively.

18. Audio data transcoding and sending apparatus according to one of claims 1 to 8, characterized in that:

the apparatus further comprises first to Mth audio transcoding and transmitting units each comprising said first to Nth audio transcoding and transmitting means, wherein M is a predetermined integer greater than 1;

the apparatus further includes means for multiplexing and transmitting at different times outputs of the first to nth encoded data of the respective first to nth audio transcoding and transmitting means of the first to mth audio transcoding and transmitting units; and

the multiplexed outputs of the first to Mth audio transcoding and transmitting units are transmitted to the first to Mth transmission lines.

19. Audio data transcoding and transmitting device according to one of claims 1, 3, 6 and 8, characterized in that:

the apparatus further comprises common audio data decoding means for decoding input audio coded data and outputting it to a plurality of audio transcoding and transmitting means among the first to nth audio transcoding and transmitting means; and

each of the plurality of audio transcoding and transmitting apparatuses encodes data obtained by decoding input audio encoded data by encoding data output by the audio data decoding apparatus.

20. Audio data transcoding and transmitting device according to one of claims 2, 4 and 7, characterized in that:

the apparatus further comprises a common audio data decoding means for decoding input audio coded packet data and outputting it to a plurality of audio transcoding and transmitting means among the first to nth audio transcoding and transmitting means; and

each of the plurality of audio transcoding and transmitting means encodes data obtained by decoding the input audio encoded data packet data by encoding the data packet data output by the audio data decoding means.

21. An audio data transcoding and receiving apparatus, comprising:

selecting means for selecting a transmission line for receiving encoded data from among first to Mth transmission lines, where M is a predetermined integer equal to or greater than 1; and

receiving means for receiving encoded data from the transmission line selected by the selecting means and extracting the encoded data received without transmission error or loss, and recombining and outputting the encoded data based on the extracted encoded data.

22. An audio data transcoding and receiving apparatus, comprising:

receiving means for receiving encoded data from the transmission line selected by the selecting means and extracting encoded data packet data received without occurrence of a transmission error or loss, and recombining and outputting the encoded data packet data according to the extracted encoded data packet data.

23. Audio data transcoding and receiving device according to claim 21, characterized in that:

the apparatus further includes means for selecting one of the data slices according to a compression ratio of the encoded data in the same frame received from the selected transmission line.

24. Audio data transcoding and receiving device according to claim 22, characterized in that:

the apparatus further includes a controller for selecting one of the data slices according to a compression ratio of packet data in the same frame received from the selected transmission line.

25. An audio transcoding and transmitting system, comprising:

audio data transcoding and transmitting apparatus as claimed in any one of claims 1, 3, 6 and 8: and

audio data transcoding and receiving apparatus according to claim 21 or 23.

26. An audio transcoding and transmitting system, comprising:

audio data transcoding and transmitting apparatus as claimed in any one of claims 2, 4, 5 and 7; and

audio data transcoding and receiving device according to claim 22 or 24.

27. Audio data transcoding and transmitting system according to claim 25 or 26, characterized in that:

the delay is controlled so that the outputs of the first to nth audio transcoding and transmitting means of the audio data transcoding and transmitting apparatus can be transmitted at different times, the apparatus further includes means for multiplexing and outputting each data piece, and the multiplexed data is transmitted to a transmission line.

28. An audio data transcoding and transmitting system, comprising:

an encoding device for outputting encoded data;

audio data transcoding and transmitting apparatus as claimed in any one of claims 1, 3, 6 and 8:

one or more audio data transcoding and receiving devices according to claim 21 or 23; and

one or more decoding devices characterized by:

the coded data from the coding device is input by the audio data transcoding and transmitting device;

the one or more audio data transcoding and receiving devices input respective outputs of the audio data transcoding and transmitting devices; and

the decoding device inputs and decodes the encoded data from the corresponding audio data transcoding and receiving device.

29. An audio data transcoding and transmitting system, comprising:

an encoding device for outputting encoded data;

audio data transcoding and transmitting apparatus as claimed in any one of claims 2, 4, 5 and 7;

one or more audio data transcoding and receiving devices according to claim 22 or 24; and

one or more decoding devices characterized by:

30. Audio data transcoding and transmitting system according to claim 28 or 29, characterized in that:

31. A transcoding and transmitting method of audio encoding data for use by an audio transcoding and transmitting apparatus, comprising:

(a) a step of inputting compressed audio coding data by a first audio coding conversion and transmission device and outputting all frames or partial frames of the input audio coding data;

(b) a step of decoding all or part of the input audio coded data and encoding data obtained by decoding the data, and outputting all or part of the frames of the obtained coded data by the second to Nth audio transcoding and transmitting apparatus, wherein N is a predetermined integer equal to or greater than 2; and

(c) the apparatus transmits the outputs of the first to Nth audio transcoding and transmitting means to the first to Mth transmission lines, where M is a predetermined integer greater than 1.

32. A transcoding and transmitting method of audio encoding data for use by an audio transcoding and transmitting apparatus, comprising:

(a) a step of inputting the compressed audio coding data packet data by the first audio code conversion and transmission device and outputting all data packets or partial data packets of the input audio coding data;

(b) a step of decoding the input audio coded data packet data by the second to nth audio transcoding and transmitting means, where N is a predetermined integer equal to or greater than 2, and coding data obtained by decoding the data, and outputting all or part of the obtained data packet data; and

33. A transcoding and transmitting method of audio encoding data for use by an audio transcoding and transmitting apparatus, comprising:

(a) a step in which the first audio transcoding and transmitting means inputs compressed audio coded data, and encodes data obtained by decoding all or part of frames of the input audio coded data, and outputs the obtained coded data;

(b) a step of encoding data obtained by decoding all or part of frames of input audio encoded data by second to Nth audio transcoding and transmitting means, where N is a predetermined integer equal to or greater than 2, and outputting the encoded data obtained; and

34. A transcoding and transmitting method of audio encoding data for use by an audio transcoding and transmitting apparatus, comprising:

(a) a first audio transcoding and transmitting means inputting compressed audio coded packet data, and encoding data obtained by decoding the input audio coded packet data, and outputting the obtained coded packet data;

(b) a step of encoding all packet data or part of packet data obtained by decoding input audio encoded packet data by second to Nth audio transcoding and transmitting means and outputting the obtained encoded data, wherein N is a predetermined integer equal to or greater than 2; and

35. A transcoding and transmitting method of audio encoding data for use by an audio transcoding and transmitting apparatus, comprising:

(a) a step of inputting the compressed audio encoding data packet data by the first audio encoding conversion and transmission device and outputting all or part of the input audio encoding data packet data;

(b) a step of copying all or a part of packet data of the audio coded packet data input to the first audio transcoding and transmitting apparatus by second to nth audio transcoding and transmitting apparatuses, and outputting the packet data obtained by the copying, wherein N is a predetermined integer greater than or equal to 2; and

36. A transcoding and transmitting method of audio encoding data for use by an audio transcoding and transmitting apparatus, comprising:

(a) a step in which the first audio transcoding and transmitting means inputs compressed audio coded data, decodes the input audio coded data, and encodes data obtained by the decoding and outputs all or part of the obtained frames;

(b) a step of decoding input audio coded data by the second to Nth audio transcoding and transmitting apparatuses, and coding data obtained by the decoding, and outputting all or part of frames of the obtained coded data, wherein N is a predetermined integer equal to or greater than 2; and

37. A transcoding and transmitting method of audio encoding data for use by an audio transcoding and transmitting apparatus, comprising:

(a) a step in which the first audio transcoding and transmitting means inputs compressed audio coded packet data, decodes the input coded packet data, and encodes data obtained by the decoding, and outputs all or part of the coded packet obtained by the encoding;

(b) a step of decoding input coded data packet data by the second to nth audio transcoding and transmitting apparatuses, and coding the data packet obtained by the decoding, and outputting all or part of the data packet obtained by the coding, wherein N is a predetermined integer equal to or greater than 2; and

38. A transcoding and transmitting method of audio encoding data for use by an audio transcoding and transmitting apparatus, comprising:

(a) inputting compressed audio coding data by a first audio coding conversion and sending device, and outputting all frames or partial frames;

(b) a step of decoding input audio coded data by the second to Nth audio transcoding and transmitting apparatuses, and coding data obtained by the decoding, and outputting all or part of frames of the coded data obtained by the coding, wherein N is a predetermined integer equal to or greater than 2; and

39. Audio data transcoding and transmission method according to any of claims 31, 33, 36 and 38, characterized in that:

40. Audio data transcoding and transmission method according to any of claims 32, 34, 35 and 37, characterized in that:

41. The audio data transcoding and transmitting method according to any of claims 33-34 and 36-37, characterized by:

in the step (a), the first audio transcoding and transmitting apparatus decodes the input encoded data, and encodes the data obtained by the decoding by compressing the data at a compression ratio equal to or higher than that of the input encoded data.

42. The audio data transcoding and transmitting method according to claim 31 or 32, wherein:

in the step (b), the second to nth audio transcoding and transmitting apparatuses decode the input encoded data and encode the data obtained by the decoding by compressing the data at a compression ratio equal to or higher than that of the input encoded data.

43. Audio data transcoding and transmission method according to any of claims 33, 34, 36, 37 and 38, characterized in that:

in the step (b), the second to nth audio transcoding and transmitting apparatuses decode input encoded data and encode data obtained by the decoding by compressing the data at a compression ratio equal to or higher than that of the first audio transcoding and transmitting apparatus.

44. Audio data transcoding and transmission method according to one of claims 31 to 38, characterized in that:

outputting each output of the second to Nth audio transcoding and transmitting devices and the output of the first audio transcoding and transmitting device at different times.

45. Audio data transcoding and transmission method according to one of claims 31 to 38, characterized in that:

selecting a compression ratio for encoding of at least one of the first to Nth audio transcoding and transmitting apparatuses according to available frequency bands of the first to Mth transmission lines, and transmitting the selected compression ratio to the first to Mth transmission lines.

46. Audio data transcoding and transmission method according to one of claims 31 to 38, characterized in that:

47. The audio data transcoding and transmitting method according to any of claims 31 to 34 and 36 to 38, characterized in that:

in the first to nth audio transcoding and transmitting apparatuses, data obtained by decoding data by a common audio data decoding apparatus is provided for a plurality of audio transcoding and transmitting apparatuses for encoding data obtained by decoding input audio data.

48. An audio data transcoding and receiving method, comprising:

a step of selecting a transmission line for receiving encoded data from first to Mth transmission lines, where M is a predetermined integer equal to or greater than 1; and

a step of receiving encoded data from the selected transmission line, extracting audio encoded data received without occurrence of a transmission error or loss, and recombining and outputting the audio encoded data based on the extracted encoded data.

49. An audio data transcoding and receiving method, comprising:

a step of selecting a transmission line for receiving the encoded packet data from first to Mth transmission lines, wherein M is a predetermined integer equal to or greater than 1; and

a step of receiving audio coded data packet data from the selected transmission line, extracting coded data packet data received without transmission error or loss, and recombining and outputting audio coded data packet data according to the extracted coded data packet data.

50. The audio data transcoding and receiving method of claim 48, wherein:

one data piece is selected according to the compression ratio of the encoded data in the same frame received from the selected transmission line.

51. The audio data transcoding and receiving method of claim 49, wherein:

one of the data slices is selected according to a compression ratio of packet data in the same frame received from the selected transmission line.

52. The audio data code conversion and transceiving method is characterized in that:

audio encoded data transmitted in the audio data transcoding and transmitting method according to any one of claims 31, 33, 36 and 38 is received in the audio data transcoding and receiving method according to claim 48 or 50.

53. The audio data code conversion and transceiving method is characterized in that:

audio encoded data transmitted by the audio data transcoding and transmitting method according to any one of claims 32, 34, 35, and 37 is received by the audio data transcoding and receiving method according to claim 49 or 51.

54. An audio data transcoding and transmitting apparatus which inputs audio encoded data and outputs the data after performing transcoding, comprising:

a plurality of audio transcoding and transmitting apparatuses for outputting an input audio encoded data stream and an audio encoded data stream obtained by decoding and re-encoding the input audio encoded data, or outputting a plurality of audio encoded data streams obtained by re-encoding data obtained by decoding the input audio encoded data, characterized in that:

the plurality of audio transcoding and transmitting devices output all or part of the input audio encoded data and the re-encoded audio encoded data, or output all or part of the re-encoded audio encoded data; and

and transmitting the plurality of audio coding data pieces output by the plurality of audio coding conversion and transmission devices to one or more transmission lines.

55. Audio data transcoding and transmitting device according to claim 54, characterized in that:

one of the plurality of audio transcoding and transmitting devices encodes data at a compression ratio equal to or higher than that of the other audio transcoding and transmitting devices.

56. An audio transcoding and receiving apparatus for receiving audio coded data transmitted to a transmission line by the audio transcoding and transmitting apparatus according to claim 54, comprising:

means for selecting a transmission line from the one or more transmission lines to receive the data; and

means for receiving the audio encoded data from the selected transmission line and recombining the audio encoded data based on the correctly received encoded data.

57. An audio code transmission system comprising: one or more audio transcoding and transmitting devices according to claim 54 and one or more audio transcoding and receiving devices according to claim 56, characterized in that:

the audio code conversion and transmission equipment receives the coded data transmitted by the equipment for distributing the audio coded data and outputs the coded data which is converted and coded; and

and the audio code conversion and receiving equipment receives the coded data output by the audio code conversion and sending equipment.