JPH0993131A - Decoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To output each data by inputting directly the video stream of the MPEG2 system, a program stream and a transport stream to the decoder. SOLUTION: A serial interface signal of compression video data by n-channels inputted to an input terminal 1 is converted into parallel compression video data by an S/P conversion circuit 21, decoded by a decoder 22 and the information of header data is fed to a control circuit 5. Compressed video data are fed to video decoders 411 -41n via reception buffers 31 -3n for each channel under the control of the control circuit 5 and decoded. Furthermore, changeover switches 431 -43n are switched to output video signals from the video decoders 411 -41n or delay memories 421 -42n to a channel changeover device 6 and a video image is outputted to a monitor 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decoding device for decoding serial compressed data transmitted via a serial digital data interface.

[0002]

2. Description of the Related Art Conventionally, in order to compress and encode video data, an international standard MPEG (Moving Pictur) has been used as a high-efficiency compression and encoding method utilizing correlation of video data.
e Experts Group) method has been proposed.

In the MPEG system, the MPEG1 system for storage media such as a so-called CD-ROM or a hard disk which is a read-only memory using a compact disc (CD), and communication and broadcasting media in addition to the storage media The standardization of the MPEG2 system for application to the above is progressing.

Also, regarding audio data, in parallel with standardization of video data, the MPEG1 system and MP
Standardization of a compression encoding method for high quality and high efficiency stereo audio data by the EG2 method is under way. According to the MPEG2 method of this audio data, multi-channel surround coding is performed using audio data of a plurality of channels, and functions such as multi-lingual are provided.

When such a video stream as a coded video data stream and an audio stream as a coded audio data stream according to the MPEG2 system or a stream of coded data such as other computer data are applied to an actual application. In order to integrate these data streams, it is necessary to make the formats compatible with the formats of communication systems such as storage media and networks. Accordingly, MPEG systems have been proposed that synchronize and multiplex video, audio, and other data.

In this MPEG system, the MPEG1 system, which is a standard for storage media, and the MPE
The MPEG2 system, which is a standard for a wider range of applications than the G1 system, has been proposed.

This MPEG2 system uses two types of formats. One format is a program stream in which video data, audio data, and other data are multiplexed as one program, and the other format is a plurality of programs.
It is a transport stream multiplexed with a stream of a book.

[0008]

The above-mentioned M
In order to display an image using a video stream based on the PEG2 system, a dedicated decoder device, an amplifier, a monitor, and the like are used in combination, and complicated wiring is required to install these devices.

Further, in the MPEG2 system, it is desired to realize a decoding device which can directly input a program stream and a transport stream and decode and output a plurality of multiplexed data.

Therefore, in view of the above situation, the present invention provides MP
It is intended to provide a decoding device capable of directly inputting an EG2 type video stream, a program stream and a transport stream and outputting each data.

[0011]

A decoding device according to the present invention comprises a serial interface decoding means for converting serial compressed data transmitted via a serial interface into parallel compressed data and decoding the serial compressed data, and the serial interface decoding means. And decoding means for decoding the compressed data of.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a first embodiment of a decoding device according to the present invention. This decoding device is a decoding device for inputting and processing a video stream.

This decoding device includes a serial interface decoder 2 which is a serial interface decoding means for converting serial compressed data transmitted via a serial interface into parallel compressed data and decoding the compressed data, and the compressed data from the serial interface decoder 2. comprising a plurality of decoder 4 ₁ to 4 _n is a decoding means for decoding.

Here, the compressed data is a video signal of at least one channel which is synchronized with a horizontal synchronizing signal of video data and is compressed in a compression format using frame correlation.

Specifically, a serial interface signal including an MPEG2 video stream is input to the input terminal 1 of the decoding device shown in FIG. The serial interface signal is a serial digital interface (SDI) which is one of the interfaces for transmitting data used in video equipment such as television and audio equipment such as radio to and from other video equipment and audio equipment. ) A signal based on a format-based interface such as a serial digital data interface (SDDI) system capable of handling compressed video data through a single communication path.

The SDI format is a standard for digital audio signals and video signals, which issues standards relating to television and video engineering. The Society of Motion Picture and Televisi
on Engineerings (SMPTE)) SMPTE-295M. This standard is basically a signal standard for the digital signal standard D-1 format or D-2 format.

Based on this SDI format, SD
The DI format is constructed. The schematic structure of this SDDI format is shown in FIG.

The frame format of the SDDI format shown in FIG. 2A, that is, the vertical format is composed of 1716 dots in the horizontal direction and 525 lines in the vertical direction, and has a data portion DT ₁ and a data portion DT ₂ . Blank data sections BDT ₁ and BDT ₂ are inserted in front of the first data section DT ₁ and the second data section DT ₂ , respectively. Also, the data sections DT ₁ and DT ₂ and the blank data section BDT
Before and after ₁ , ₁ and BDT ₂ , a 4-bit start synchronization code SAV indicating the start of the active line and an end synchronization code EAV indicating the end of the active line are placed. Further, between the start synchronization code SAV and the end synchronization code EAV, an ancillary data unit ANC which is 268 bits of auxiliary data is placed.

The line format, that is, the horizontal format shown in FIG. 2B has a 10-bit width, a 4-byte end synchronization code EAV, and a 268-byte ancillary data section AN.
C, 4 bytes of start synchronization code SAV, and 1440 bytes of payload part PAD.

When transmitting the signal in the SDDI format, parallel-serial conversion and transmission path coding are performed in the same manner as the signal in the SDI format, and the signal is transmitted as a serial interface signal having a data rate of 270 Mbps shown in FIG. 2C. To be done.

Next, FIG. 3 shows an example of a concrete structure of the SDDI format.

FIG. 3A is the line format shown in FIG. 2B. Payload part P in this line format
In AD, for example, as shown in FIG. 3B, a so-called packet in which data and a flag are combined is called a flag F.
G ₁ , data area DA ₁ , flag FG ₂ , data area D
A _2, flag FG _3, a data area DA _3, flag FG _4, data area DA _4, flag FG _5, constituted by successive ... a plurality min.

As shown in FIG. 3C, one flag FG is composed of a type area TP, a byte count area BC, and an error correction code ECC. The type area TP shows the contents of data in the data area DT, the byte count area BC shows the length of data in the data area DT, and the error correction code ECC checks the type area TP and the byte count area BC for each medium. A thumb or CRC (Cyclic Redundancy Check) code or the like is shown. With the error correction code ECC, the type area T
Error detection and correction of the P and byte count areas BC are performed. The type area TP and the byte count area BC are so-called header data.

The above-mentioned SD input to the input terminal 1
The serial interface signal in the DI format is a signal in which compressed video data for a plurality of channels are time-division multiplexed, for example. Here, when the serial interface signal is compressed video data for n channels, the compressed video data for n channels is first converted into a serial / parallel (S / P) conversion circuit 21 in the serial interface decoder 2. Sent to and converted into parallel compressed video data. This parallel compressed video data is sent to the decoder 22.

The decoder 22 decodes the sent parallel compressed video data, and sends the header data information to the control circuit 5 including a CPU or the like. As a result, the control circuit 5 determines the size and content of the video data sent to the decoder 22. Then, under the control of the control circuit 5, the compressed video data portion is separated and stored in the _n reception buffers 3 _{1 to} 3 _n for each channel.

The compressed video data stored in the reception buffers 3 _{1 to} 3 _n are sent to the respective decoders 4 ₁ to 4 _n . These decoders 4 ₁ to 4 _n is a video decoder, comprising comprises delay memory, and a changeover switch respectively.

In the decoders 4 ₁ to 4 _n , the sent compressed video data is sent to the video decoders 41 _{1 to} 41 _n and decoded under the control of the control circuit 5.

In the receiving buffers 3 _{1 to} 3 _n , the transmission speed of the serial interface signal input to the decoding device and the video decoder 4 in the decoders 4 ₁ to 4 _n are set.
Since the difference from the transmission rate of the compressed video data input to 1 _{1 to} 41 _n is absorbed, the input serial interface signals can be normally decoded by the video decoders 41 _{1 to} 41 _n .

Here, the video signals decoded and output by the respective video decoders 41 _{1 to} 41 _n may be replaced with the order in which they are displayed on the monitor 7, which is a display means for displaying the video signals. is there. This is MPEG2
This is because the order of pictures, which is a unit of one screen used in the MPEG method, is changed by the prediction processing by the method.

Therefore, for example, in the decoder 4 ₁ , the video signal of the picture whose display order is later is stored in the delay memory 42 ₁ and delayed. The video signal of the picture stored in the delay memory 42 ₁ is sent to the terminal “a” of the changeover switch 43 ₁ , and later, the video decoder 4
Video signal of the picture that is being decoded output 1 ₁ is sent to the terminal b of the changeover switch 43 _1. The change-over switch 43 ₁ is switch-connected to the terminal a or the terminal b under the control of the control circuit 5, so that the video signals of the respective pictures are displayed in the monitor 7 in the order in which they are displayed on the channel changer 6.
Is output to In each of the n decoders 4 ₁ to 4 _n , the same processing operation as the above-described processing operation in the decoder 4 ₁ is performed, so that the video signals of each channel are displayed in the monitor 7 in the order in which they are switched. 6 is output.

In the channel changer 6, the n
The video signal of the channel is switched and sent to the monitor 7. As a result, the monitor 7 displays 1 of the n channels.
Video of a channel or multiple channels is output.

In the first embodiment of the above-mentioned decoding device, compressed video data transmitted as serial digital data can be directly input to display an image.

Next, FIG. 4 shows a schematic configuration of a second embodiment of the decoding apparatus according to the present invention. This decoding device is a decoding device for inputting and processing a program stream and a transport stream.

The above SDDI input to the input terminal 1.
The format serial interface signal is
The compressed video data, compressed audio data, and system information data are, for example, time-division multiplexed signals.
This serial interface signal is first sent to the serial / parallel (S / P) conversion circuit 21 in the serial interface decoder 2 and converted into parallel compressed data.

This parallel compressed data is sent to the decoder 2
2 and is decoded. The information of the header data of each compressed data separated by this decoding process is CP
It is sent to the control circuit 10 composed of U and the like. As a result, the control circuit 10 determines the size and content of each data sent to the decoder 22. Then, under the control of the control circuit 10, the compressed data is transferred to the separation unit 91 in the decoder 9.
Sent to

In the separating unit 91, when the input serial interface signal is a program stream, the compressed data sent is a video packet under the control of the control circuit 10 based on the information of the header data of the program stream. And audio packets. The video packet and audio packet are sent to and stored in the corresponding video buffer 92 or audio buffer 96, respectively. Further, the system information is sent to the system decoder 99 via the system buffer 98 and decoded.

On the other hand, when the input serial interface signal is a transport stream, the separating section 91 is controlled by the control circuit 10 to send a plurality of sets of programs, that is, a plurality of transports forming a so-called multi-program. Program packets are selected from within the packet. Further, the program packet is controlled by the control circuit 10 based on the information of the header data,
It is divided into video packets and audio packets, and these video packets and audio packets are sent to and stored in the corresponding video buffer 92 or audio buffer 96, respectively. Further, system information is also stored in the system buffer 98. The system information stored in the system buffer 98 is sequentially sent to the system decoder 99 to be decoded.

The video decoder 93 and the audio decoder 97 are controlled by the system information decoded by the system decoder 99. As a result, the video decoder 93 extracts the compressed video data from the video buffer 92 and performs the decoding process, and the audio decoder 97 extracts the compressed audio data from the audio buffer 96 and performs the decoding process.

As described in the first embodiment, the video signals decoded and output by the video decoder 93 may be exchanged in the order in which they are displayed on the monitor 7. . Therefore, the video signal of the picture whose display order is later is stored in the delay memory 94 and delayed. The video signal of the picture stored in the delay memory 94 is sent to the terminal a of the changeover switch 95, and the video signal of the picture decoded and output by the video decoder 93 later is the terminal b of the changeover switch 95.
Sent to The changeover switch 95 is connected to the terminal a or the terminal b under the control of the control circuit 10 so that the video signals of the pictures are output to the monitor 7 in the order in which they are displayed. As a result, the image is displayed on the monitor 7.

The audio signal decoded and output by the audio decoder 97 is sent to the speaker 8 which is an audio output device, so that audio is output to the outside. At this time, the system decoder 99 controls the video decoder 93 and the audio decoder 97 to output synchronized video and audio.

In the second embodiment of the above-mentioned decoding device, compressed data transmitted as serial digital data can be directly input to output video and audio.

[0043]

As is apparent from the above description, the decoding apparatus according to the present invention includes serial interface decoding means for converting serial compressed data transmitted via the serial interface into parallel compressed data and decoding the serial compressed data. By including the decoding means for decoding the compressed data from the serial interface decoding means, serial compressed data can be directly input from one input terminal without performing complicated wiring, and video and audio can be output. Can be output. Further, since it can be easily connected to a reproducing apparatus or a broadcasting system of an MPEG2 system storage medium having an input terminal for inputting serial compressed data by the serial interface, it is possible to monitor data transmitted from the reproducing apparatus, It can be used as a dedicated image receiving device of a broadcasting system.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a decoding device according to the present invention.

FIG. 2 is a schematic configuration diagram of an SDDI format.

FIG. 3 is a diagram showing an example of a specific configuration of a line format.

FIG. 4 is a schematic configuration diagram of a first embodiment of a decoding device according to the present invention.

[Explanation of symbols]

 2 Serial interface decoder 3 Receive buffer 4, 9 Decoder 5, 10 Control circuit 6 Channel switch 7 Monitor 8 Speaker

Claims (5)

[Claims] 1. A serial interface decoding means for converting serial compressed data transmitted through a serial interface into parallel compressed data and decoding the serial compressed data, and a decoding means for decoding the compressed data from the serial interface decoding means. A decoding device comprising: 2. The compressed data is a video signal of at least one channel which is synchronized with a horizontal synchronizing signal of video data and is compressed in a compression format using frame correlation. Decoding device. 3. The decoding device according to claim 2, further comprising display means for displaying a video signal output from said decoding means. 4. The decoding device according to claim 1, wherein the compressed data comprises video data, audio data, and system information data. 5. The decoding device according to claim 4, wherein the compressed data is data for a plurality of channels.