JP2003348489A - Broadcast receiver - Google Patents

Abstract

(57) [Summary] To accurately synchronize a video signal and an audio signal. SOLUTION: Time information is added to a video signal before signal processing by a signal processing means 4, time information is extracted after signal processing by an elapsed time calculation means 6, and the time required for the signal processing is calculated. Only, the audio data decoded by the audio decoding means 3 is stored in the temporary storage means 7 and the output is delayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcast receiver for receiving a television broadcast, and more particularly to a broadcast receiver for decoding and outputting a digital signal.

[0002]

2. Description of the Related Art Digital television broadcasts, such as BS digital television broadcasts, have gained a reputation for multichannel and high image quality, and have been rapidly spreading in recent years.

FIG. 4 is a block diagram of a conventional broadcast receiver for receiving digital television broadcasts. Broadcast receiver 50
Is a tuner 51 for selecting and receiving a broadcast, a descrambler 52 for descrambling, and a demultiplexer 53 for demultiplexing a TS (transport stream) signal.
A video decoder 54 for decoding a compression-encoded video signal, an audio decoder 55 for decoding a compression-encoded audio signal, and a memory 5 for storing additional information and the like.
6 and a signal processing device 5 for processing the decoded video signal
7, CPU 58, memory 59, descrambler 5
And a card interface 60 for transmitting and receiving information to and from an IC card 60a in which information for descrambling is stored.

[0004] Further, the demultiplexer 53 refers to the PID (Packet IDentification) of the TS header and stores it in a TS header parser 53 a for allocating the packet to a PES (Packetized Elementary Stream) or section, and stores the video signal and the audio signal or the memory 59. PES parser 53b for distributing signals, section parser 53c for storing section signals in memory 59, video decoder interface 53d, audio decoder interface 53e, memory interface 53
f.

[0005] The operation of the conventional broadcast receiver 50 will be described below. RF (Radio Freq) received by an antenna not shown
uency) signal is supplied to the tuner 51. The tuner 51 outputs a TS signal as a result of channel selection, detection, and demodulation. The TS signal is input to the descrambler 52. Here, if the received digital television broadcast is scrambled such as a pay broadcast, the descrambler 52 stores the received digital television broadcast in the IC card 60a.
Descramble the scramble based on the information to decipher. The descrambled TS signal is input to the demultiplexer 53. Here, the TS header parser 53a
Is classified into PES data or section data with reference to the PID described in the header constituting
In the case of ES, it is input to the PES parser 53b, and in the case of a section, it is input to the section parser 53c. The PES parser 53b converts the PES packet into video, audio or
It is determined whether the packet is stored in the memory 56 and then executed.
d, input to the audio decoder interface 53e and the memory interface 53f. In the case of a section, section data is fetched by the section parser 53c and input to the memory 56 via the memory interface 53f. The video signal extracted by the demultiplexer 53 is decoded by a video decoder 54, and the audio signal is decoded by an audio decoder 55. The decoded video signal is further processed by the signal processing device 57. For example, resolution conversion to match the resolution of a display device (not shown), pixel interpolation, and the like are performed. Here, the processed video signal is output to a display device (not shown) and displayed. The decoded audio signal is output by an audio playback device (not shown) such as a speaker.

As described above, since a video signal is output to a display device (not shown) via a signal processing device 57 located downstream of the video decoder 54, the output of decoded video and audio is out of synchronization. was there.

In order to solve this problem, a conventional audio decoder 55 has a function of providing a temporary storage area such as a memory or a buffer before decoding, and having a function of delaying decoding in order to synchronize with output of a video signal. there were.

[0008]

However, in the conventional delay method, since the delay is performed before decoding, the delay is performed after mixing with another PCM (Pulse Code Modulation) sound such as an internal sound effect. There was a problem that it could not be done.

Also, in the delay before decoding, when there are a plurality of output ports, only the same delay time can be set, so that the delay time of the video signal and the audio signal cannot be set for each output port. there were.

Another problem is that the output delay of the audio signal cannot be set by automatically detecting the delay of the video signal which differs depending on the system. The present invention has been made in view of such a point, and an object of the present invention is to provide a broadcast receiver that can output a video signal and an audio signal in accurate synchronization.

[0011]

According to the present invention, in order to solve the above-mentioned problems, in a broadcast receiver for receiving a television broadcast, a video decoding means for decoding a compressed or encoded video signal, Audio decoding means for decoding a decoded audio signal; time information adding means for adding time information to the decoded video signal; and signal processing corresponding to a display device for the video signal to which the time information has been added. Signal processing means for detecting the time information, calculating the elapsed time by the signal processing, calculating the elapsed time, and temporarily storing the decoded audio signal according to the elapsed time. And a broadcast receiver.

According to the above arrangement, the time information added to the video signal decoded by the video decoding means is detected by the elapsed time calculation means after passing through the signal processing means, and the elapsed time of the processing by the signal processing means is obtained. Is calculated, and the voice decoded by the voice decoding unit is temporarily stored by the temporary storage unit and output according to the elapsed time.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a principle configuration diagram of a broadcast receiver according to an embodiment of the present invention.

FIG. 1 omits parts for receiving broadcasts. The broadcast receiver 1 corresponds to a video decoding unit 2 for decoding a compressed or encoded video signal, an audio decoding unit 3 for decoding a compressed or encoded audio signal, and a display device for decoding the decoded video signal. Thus, the signal processing means 4 for performing signal processing, the time information adding means 5 for adding time information to the video signal decoded before the signal processing,
It has an elapsed time calculation means 6 for calculating the time elapsed by the signal processing, and a temporary storage means 7 for temporarily storing the decoded audio signal.

The video decoding means 2 is connected to input the decoded video signal to the signal processing means 4.
Are connected to output a video signal to a display device (not shown). On the other hand, the audio decoding means 3 is connected so as to input the decoded audio signal to the temporary storage means 7, and the temporary storage means 7 is connected so as to output the audio signal to an audio output device (not shown). Time information adding means 5
Are arranged such that time information can be added to the video signal before the video signal decoded by the video decoding means 2 is input to the signal processing means 4. The elapsed time calculation means 6 is arranged so that time information can be detected from the video signal processed by the signal processing means 4, and is connected to the time information addition means 5 and can receive a signal from the time information addition means 5. And is connected to the temporary storage means 7 to store the signal
It is possible to send to.

Here, the signal processing means 4 performs resolution conversion so as to match the resolution of a display device (not shown), interpolation of pixels accompanying the resolution conversion, and the like. Hereinafter, the operation of the broadcast receiver 1 will be described.

When the compressed or encoded video signal and audio signal are input to the video decoding means 2 and the audio decoding means 3, respectively, decoding is performed. At this time, the synchronization between the video signal and the audio signal is maintained by a timing signal (not shown). The video signal decoded by the video decoding means 2 passes through the signal processing means 4, so that a delay occurs, and the video signal is not synchronized with the audio signal output from the audio decoding means 3. Therefore, in the broadcast receiver 1 according to the embodiment of the present invention, the time information adding means 5 adds time information to the video signal output from the video decoding means 2. For example, time information is added to a blanking period such as VBI (vertical blanking interval) or HBLK (horizontal blanking) of a video signal. After the signal processing unit 4 processes the video signal, the elapsed time calculation unit 6 detects the added time information from the video signal. Here, the elapsed time calculating means 6 refers to the time information added to the video signal from the time information adding means 5, compares the time information with the detected time information, and calculates the elapsed time required for the signal processing by the signal processing means 4. I do. The calculated elapsed time is input to the temporary storage unit 7, and the temporary storage unit 7 accumulates the audio signal decoded by the audio decoding unit 3 for the input elapsed time and outputs it to an audio output device (not shown).

As described above, the time information is added to the video signal before the signal processing by the signal processing means 4, the time information is taken out after the signal processing, and the time required for the signal processing is calculated. By accumulating the audio data decoded in step 3 in the temporary storage means 7 and delaying the output, the output video signal and audio signal can be accurately synchronized.

Hereinafter, embodiments of the present invention will be described in detail. FIG. 2 is a hardware configuration diagram of the broadcast receiver according to the embodiment of the present invention. The broadcast receiver 10 includes a tuner 11 for selecting and receiving a broadcast, a descrambler 12 for descrambling, a demultiplexer 13 for demultiplexing a TS signal, and a video decoder 14 for decoding a compression-encoded video signal. An audio decoder 30 for decoding a compression-encoded audio signal; a memory 30a associated with the audio decoder 30; a memory 15 for storing additional information and the like; and a signal processing device 16 for processing the decoded video signal A time stamp setting device 17, a time stamp detecting device 18, a CPU 19, a memory 20, and a card interface 21 for transmitting and receiving information to and from an IC card 21a in which information for descrambling by a descrambler 12 is stored. And

In FIG. 2, the video decoding means 2 of FIG. 1 is a video decoder 14, the audio decoding means 3 is an audio decoder 30, the signal processing means 4 is a signal processing device 16, and the time information adding means 5 is a time stamp setting device. 17, the elapsed time calculating means 6 corresponds to the time stamp detecting device 18, respectively. The part corresponding to the temporary storage means 7 in FIG. 1 will be described later.

The time stamp setting device 17 is provided between the video decoder 14 and the signal processing device 16 so as to be able to add time information (hereinafter referred to as a time stamp) to the decoded video signal. The time stamp detecting device 18 is installed so that the time stamp can be detected from the video signal processed by the signal processing device 16. The time stamp detecting device 18 includes a time stamp setting device 17 and an audio decoder 30.
Is connected to

The details of the audio decoder 30 will be described below. FIG. 3 is a configuration diagram of the audio decoder according to the embodiment of the present invention. Here, the configuration of the audio decoder 30 when there are two output ports is shown. These two output ports are, for example, an output for a television speaker and a digital VTR (VideoTape Recorder).
er). The video and audio signals are MPEG-2 (Moving Picture Experts Group-
2) It is assumed that the data is compressed and encoded in the format.

The audio decoder 30 generates an STC (synchronized reproduction) of video and audio generated by a PLL (phase synchronization circuit) 40, which is omitted in FIG. 2, by referring to a PCR (Program Clock Reference) of a TS packet. Syst
em Time Clock), a memory interface 32 that is an interface with a buffer or memory 20 (not shown), and a PES (Packetiz
ed Elementary Stream), the time management information P
TS (Presentation Time Stamp) and ES (Elementar
y Stream) and a PES decoder 33 for separating and extracting
An AV synchronization control unit 34 for controlling the synchronization with the video by comparing the time of the timer 31 with the PTS, a decoder 35 for decoding the audio signal of the MPEG-2 format, and a PCM (Pulse A sampling frequency conversion unit 36 for converting a sampling frequency of an audio signal in a Code Modulation format, a PCM mixing unit 37 for mixing a decoded audio signal with an external audio signal, and a PC
A PCM output buffer 38 which is a buffer for outputting an M-format audio signal. Further, the memory interface 32 includes delay control units 32a and 32b.

In FIG. 3, the delay control unit 32a,
32b and the memory 30a correspond to the temporary storage means 7 of FIG. The delay control unit 32a outputs the output 1 of the decoder 35.
On the side, it is connected in parallel between the PCM mixing unit 37 and the PCM output buffer. The delay controller 32b is connected in parallel between the PCM mixer 37 and the PCM output buffer on the output 2 side of the decoder 35. The delay control units 32a and 32b receive the delay control signal from the time stamp detection device 18 in FIG. 2, and transmit the audio signal to the memory 30a for a time corresponding to the processing delay in the signal processing device 16, and After a lapse of time, the audio signal is extracted from the memory 30a and input to the PCM output buffer 38.

The PES decoder 33 stores, in addition to the received PES and ES, the memory 2 shown in FIG.
AAC (Advanced Audio Codin)
g) Format audio signal is input.

The operation of the broadcast receiver 10 according to the present invention will be described below with reference to FIGS. An RF signal received by an antenna (not shown) is input to the tuner 11. The tuner 11 outputs a TS signal as a result of channel selection, detection, and demodulation. The TS signal is input to the descrambler 12. Here, the received digital television broadcast is
If the content is scrambled, such as a pay broadcast, the descrambler 12 descrambles the data based on the information for decryption stored in the IC card 21a. The descrambled TS signal is supplied to the demultiplexer 13.
Is input to The demultiplexer 13 separates section data such as a video signal, an audio signal, or program information from the TS signal. When the video signal separated from the TS by the demultiplexer 13 is input to the video decoder 14, the video signal is decoded. The time stamp is added to the video signal decoded by the video decoder 14 by the time stamp setting device 17 so that the VBI or HB
It is added to a blanking period such as LK. After that, the signal processing device 16 performs resolution conversion in accordance with the resolution of a display device (not shown) and pixel interpolation accompanying the resolution conversion. The video signal processed by the signal processing device 16 is output to a display device (not shown). Before that, the time stamp set by the time stamp setting device 17 is converted by the time stamp detecting device 18 into VBI or HB.
The signal is extracted from the LK and compared with a time stamp before being input to the signal processing device 16. Thereby, the delay time in the signal processing device 16 is automatically calculated. Next, information on the delay time calculated by the time stamp detection device 18 is output to the audio decoder 30 as a delay control signal.

When the delay control signal is received by the delay control unit 32a or 32b, the audio decoder 30 decodes the audio signal mixed by the PCM mixing unit 37,
The data is not immediately output to the PCM output buffer 38,
0a. That is, the audio signal is temporarily held for a time corresponding to the delay time in the signal processing device 16 included in the delay control signal. Here, the delay control units 32a, 3
In 2b, the time to be stored in the memory 30a can be set separately. When the time corresponding to the delay time elapses, the delay control units 32a and 32b store the audio signal temporarily stored in the memory 30a in the PCM output buffer 38.
To an audio playback device (not shown).

As described above, the time stamp is added to the video signal before the signal processing in the signal processing device 16, the time stamp is taken out after the signal processing, and the time required for the signal processing is calculated. Under the control of 32a or 32b, the audio signal decoded by the audio decoder 30 is stored in the memory 30a and the output is delayed, so that the output video signal and audio signal can be accurately synchronized.

Further, according to the above configuration, the audio signal mixed by the PCM mixing unit 37 is temporarily stored and delayed,
It can be reproduced in synchronization with the video signal. Also,
According to the above configuration, when a plurality of output ports exist in the audio decoder 30, a delay time can be set for each output port.

In the above description, the memory 30a for delay is provided independently, but the memory 20 may be used, or a buffer of the audio decoder 30 may be used as a temporary storage area.

In the above description, the audio decoder 30 is described as having two output ports. However, the number is not limited to one, and may be one or two or more.

[0032]

As described above, according to the present invention, the time information is added to the decoded video signal, the signal processing corresponding to the display device is performed, the time information is detected, and the progress of the signal processing is performed. The time is automatically calculated and the decoded audio signal is temporarily stored and output according to the elapsed time, so that the video signal and the audio signal can be accurately synchronized and output. It is possible.

Further, according to the present invention, the audio signal mixed with the PCM audio can be temporarily stored, delayed, and reproduced in synchronization with the video signal. Further, according to the present invention, when a plurality of output terminals are present in the audio decoding means, a delay time can be set for each output terminal.

[Brief description of the drawings]

FIG. 1 is a principle configuration diagram of a broadcast receiver according to an embodiment of the present invention.

FIG. 2 is a hardware configuration diagram of the broadcast receiver according to the embodiment of the present invention.

FIG. 3 is a configuration diagram of an audio decoder according to the embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional broadcast receiver for receiving digital television broadcast.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Broadcast receiver, 2 ... Video decoding means, 3 ... Audio decoding means, 4 ... Signal processing means, 5 ... Time information addition means, 6 ... Elapsed time calculation means, 7 ... Temporary storage means

Continuation of front page    (72) Inventor Hiroshi Adachi             6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Soni             ー Inc. F-term (reference) 5C026 DA00                 5C053 FA21 FA27 GB06 GB10 GB11                       GB38 JA07 JA22 KA01 LA06                 5C059 MA00 RB10 RC03 RC04 RC32                       RE03 UA05 UA34                 5C063 AA01 AB03 AB07 AC01 AC05                       CA12 CA16 CA20 CA38

Claims (3)

[Claims] 1. A broadcast receiver for receiving a television broadcast, comprising: a video decoding unit for decoding a compressed or encoded video signal; an audio decoding unit for decoding a compressed or encoded audio signal; Time information adding means for adding time information to the video signal, signal processing means for performing signal processing corresponding to a display device on the video signal to which the time information is added, and the time information after the signal processing Elapsed time calculating means for calculating the elapsed time elapsed by the signal processing by detecting the time information before the signal processing, and temporarily decoding the decoded audio signal according to the elapsed time. A broadcast receiver, comprising: temporary storage means for storing. 2. The broadcast receiver according to claim 1, further comprising a PCM mixing unit for mixing PCM audio between the audio decoding unit and the temporary storage unit. 3. The audio decoding means has a plurality of output terminals, and the temporary storage means temporarily stores the audio signal for each of the output terminals separately according to the elapsed time. The broadcast receiver according to claim 1.