JP3164871B2 - Audio data transmission / reception circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a high-efficiency coding apparatus for a broadcasting station. In particular, it relates to means for compressing and expanding audio data.

[0002]

2. Description of the Related Art When transferring two-channel data, in the conventional example, the data is transferred alternately with respect to time for each channel data or stored in a memory for each channel for packet transmission.

[0003]

In such a conventional example, there is a disadvantage that the transmission voice data is largely destroyed by a burst error in the transmission system.

An object of the present invention is to provide an audio data transmission / reception circuit having means for suppressing such a drawback and reducing the error probability of audio data due to a burst error in a transmission system.

[0005]

Means for Solving the Problems The present invention, in the audio data transmission and reception circuit having a transmitting means for transmitting the 2-channel audio data together with data including video data, before <br/> Symbol transmission means, the channel corresponding Conversion means for converting an analog signal related to audio data into a parallel digital signal, data length changing means for adaptively compressing the digital signal converted by the conversion means, provided for each channel; and A format conversion circuit for converting the structure of the two-channel audio data compressed by each of the data length changing means into one parallel data, and a memory means for temporarily storing the data whose structure has been converted by the format conversion circuit. And the data for one sample read from the memory means at the audio sampling frequency interval.
Characterized by comprising a framing circuit to be inserted into the data including the pre-Symbol image data.

[0006] Here, a receiving means for compressed 2-channel audio data receives audio data from the digital data including the inserted video data as one parallel data, the receiving means, the pre-Symbol image data comprising means for storing audio data for one sample from the digital data prior Symbol memory means to extract a voice sampling frequency interval containing prior Symbol framing circuit, the one sample of the audio data read out from the memory means 2 channels
Comprising means for structural transformation Le parallel data before Symbol format conversion circuit includes means for adaptively data decompression parallel data of each channel are structured converted by the format converter before Symbol data length changing means, characterized in including Mukoto means for converting parallel data decompressed by the data length changing means to an analog signal before Symbol converter
And

[0007]

[Function] Compresses digital audio data of two channels,
Format conversion to generate one parallel data,
Audio data is inserted into other digital data in units of one sample in synchronization with the audio sampling frequency and transmitted. As a result, the error probability of audio data due to a burst error in the transmission system is reduced, and the quality of the decoded audio signal is improved.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of this embodiment. In this embodiment, as shown in FIG. 1, conversion means provided for each channel as transmission means for transmitting audio data of two channels together with data including video data, and converting an analog signal relating to the audio data into a digital signal. And analog-digital / digital-analog conversion circuits 1 and 3 which are provided for channels.
Data compression / decompression circuits 2 and 4 which are data length changing means for adaptively compressing the digital signal converted by the conversion means, and the two-channel data compressed by each of the data length changing means are converted into one data. Parallel data
Format conversion circuit 5 which allocates the upper bits and the lower bits of the data and converts the structure into one parallel data
And a FIFO 6 which is a memory means for temporarily storing the data subjected to the structure conversion by the format conversion circuit 5, and the data of one sample read from the memory means at the audio sampling frequency interval in the data including the video data. And a framing circuit 18 to be inserted.
As receiving means for receiving audio data from digital data including video data in which compressed audio data is inserted as one parallel data, audio data for one sample from the digital data including the video data is output at audio sampling frequency intervals. includes extracting and the means for storing in said memory means in the framing circuit 18, a one sample of the audio data read out from the memory means 2 channels
The format conversion circuit 5 includes a means for converting the structure of the digital data into parallel data, and the data length changing means includes means for adaptively expanding the digital data whose structure has been converted by the format conversion circuit 5. The converting means includes means for converting the digital signal expanded by the length changing means into an analog signal.

Next, the operation of this embodiment will be described. FIG.
FIG. 7 is a diagram showing a change in a data structure executed in this embodiment. The two-channel analog-digital / digital-analog conversion circuits 1 and 3 convert the audio band analog signals 7 and 11 into digital signals 9 and 13 at a sampling frequency Fs, and convert the digital signals 10 and 14 into analog signals 8 and 13 at a sampling frequency Fs. This is a circuit for converting to 12. The two-channel data compression / expansion circuits 2 and 4 are circuits that adaptively compress input data by a factor of two and expand the data by a factor of two. At the time of encoding, the data compression / decompression circuits 2 and 4 output 2 / Fs
The compressed audio data of two channels is output at the speed of, and is input to the format conversion circuit 5. FIG. 2A shows the data structure at this time. For example, when the analog conversion output is an 8-bit parallel signal, both the channel 1 and the channel 2 are compressed to 1/2 by the data compression / decompression circuits 2 and 4. The compressed data is packed in the order of lower 4 bits and upper 4 bits for each channel. The format conversion circuit 5 converts the channel 1 (N−1,
N-2) and channel 2 (N-1, N-2) by 2 / Fs
Receiving at intervals, as shown in FIG. 2 (B), N-2 the data of the upper channel 1 of the parallel data, arrange in the order of N-1, N-2 data channel 2 to the lower,
Format conversion is performed in the order of N-1. By this conversion, the sampling data of channel 1 and channel 2 at the same time, for example, N-2 becomes one parallel data and is input to FIFO 6 at an interval of 1 / Fs.
Output data 17 from the FIFO 6 is input to the framing circuit 18 at 1 / Fs intervals. Framing circuit 18
The framing of the other data 19 such as video data and the data of the FIFO 6 as shown in FIG. The transmission speed at this time is higher than Fs. At the time of decoding, the sequence is reversed.

[0010]

As described above, according to the present invention, two-channel compressed audio data is format-converted into parallel data, and the data is inserted into digital data such as video in synchronism with the sampling frequency of the audio for each sample. Therefore, the transmission probability is reduced, thereby reducing the error probability of audio data due to a burst error in the transmission system and increasing the quality of the decoded audio signal.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a data structure diagram showing the operation of the embodiment of the present invention.

[Explanation of symbols]

1, 3 analog-digital / digital-analog conversion circuit (ADDA) 2, 4 data compression / expansion circuit (ADPCM) 5 format conversion circuit 6 FIFO 18 framing circuit

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Okamura 2-2-1 Jinnan, Shibuya-ku, Tokyo Japan Broadcasting Corporation (56) References JP-A-1-228333 (JP, A) International Publication 90/10993 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B 14/00-14/06 H04N 5/91-5/93 H04N 5/94-5/95

Claims (1)

(57) [Claims] 1. Two channels together with data including video data
Transmission means for transmitting channel audio dataAnd two channels
Digital video data with video data inserted
Receiving means for receiving voice data from data;Sound with
In the voice data transmitting and receiving circuit,Previous The transmission means is provided for each channel, and
Analog signals related toparallelConvert to digital signal
Conversion means for converting the data,
Adaptively compresses digital signals converted by conversion means
Data length changing means and the data length changing means
Compressed in eachTwo channels of audio data are stored in onePa
A format conversion circuit for converting the structure into the parallel data,
The data whose structure has been converted by this format conversion circuit
Memory means for storing the time, and a sound sample from the memory means.
One sample of data read at the pulling frequency interval
ToPreviousFrames to be inserted into data including video data
And a switching circuit, The receiving means is a digital data containing the video data.
The audio data for one sample from the audio sampling frequency
Means for extracting at several intervals and storing in the memory means is
Read from this memory means included in framing circuit
1 sample of audio data in two channels in parallel
Means for converting the structure into data, the format conversion circuit
Included in the format conversion circuit
Adaptively expands parallel data of channel
Means for changing the data length.
Converts parallel data expanded by means to analog signal
Means included in the conversion means Audio data
Data transmission and reception circuit.