KR0185947B1 - Method of decoding the selection program of a digital satellite broadcasting receiver and apparatus thereof - Google Patents

Abstract

The present invention relates to a selected program decoding method and apparatus for a digital satellite broadcast receiver for selecting and decoding a desired program among a plurality of programs encoded, multiplexed and transmitted in a digital satellite broadcast receiver. According to the present invention, PSI processing required for demultiplexing multiplexing allows decoding of PSI only when a table such as PAT, PMT, or CAT is completely input, thereby providing an effect of more efficient program selection and decoding.

Description

Selective program decoding method and apparatus for digital satellite broadcasting receiver

1 is a block diagram showing a general digital satellite broadcasting receiver.

2 is a block diagram showing an apparatus for decoding a selected program of a digital satellite broadcast receiver according to the present invention.

3 is a flow chart for explaining the operation of the device of FIG.

* Explanation of symbols for main parts of the drawings

21: system decoder 22: memory unit

23: micom

The present invention relates to a selective program decoding method and apparatus for a digital satellite broadcast receiver for selecting and decoding a desired program from a transport stream (hereinafter referred to as TS) in which a plurality of programs are encoded and multiplexed. The present invention relates to a selection program decoding method of a digital satellite broadcasting receiver and an apparatus for efficiently processing PSI information related to selection.

Analog satellite broadcasting is limited in satisfying people's various needs in various aspects such as image quality and data service. Therefore, with the development of digital signal processing technology (video compression technology, digital communication), the broadcasting method is changing to digital. On the other hand, in digital satellite broadcasting, voice, video data and other auxiliary data encoded in the form of bit strings are transmitted. To do this, these bit streams must be packetized and multiplexed. To this end, MPEG 2 defines the system standard (ISO / IEC 13818-1) in detail, and specifies that the audio, video data, and auxiliary data bit streams are packetized elementary stream (PES) packets, which are used as transport streams (TS). Doing.

FIG. 1 is a block diagram showing a digital receiver of a Korean Mugunghwa satellite, and is configured to decode a program selected by a user among satellite broadcast signals of a transmitted TS bit string.

In FIG. 1, the channel decoder 12 of the satellite broadcast receiver receives the satellite broadcast signal of the TS bit string transmitted thereto and applies it to the system decoder 13. The system decoder 13 separates the TS packet header from the received satellite broadcast signal of the TS bit stream, and separately outputs the video and audio data corresponding to the broadcasting station program selected by the user. The TS bit string transmitted here has a packet structure, and a multiplexed TS packet has a packet of 188 bytes having a packet header of 4 bytes and a payload portion of 184 bytes. The packet header has a PID (Packet ID) so that it knows what kind of bitstream the packet's payload contains. The payload is a section in which valid data is carried, and video and audio signals and various tables extruded according to MPEG 2 corresponding to broadcast programs of each broadcasting station are carried. Here, a table becomes a mapping table between a program and this PID when a desired program is selected and decoded from a TS packet transmitted by multiple programs encoded and multiplexed, which is referred to as PSI (Program Specific Information). PSI includes a program map table (PMT) consisting of a program number, a PID of a commercial signal corresponding to the program, and a PID of a voice signal corresponding to the program, and a PAT (Program Association Table) including each PMT as a table. have. PAT is present in TS packets with an enhanced PID of zero.

Again, in FIG. 1, the system decoder 13 receives a program number desired by the viewer through the microcomputer 11 when switching channels or turning on the power, finds the PID of the PMT corresponding to the program in the PAT, and then the PMT. Is stored in the first memory unit 14. The system decoder 13 finds the PMT stored in the first memory unit 14 and finds the PID of each video and audio. Once the PID is found, only packets of the corresponding PID are decoded unless the channel or PMT is changed. The video decoder 16 separates the PES packet header from the video packet, decodes and restores the bit string of the video data, and outputs the restored video data to the NTSC encoder 18. Here, the second memory unit 17 operates as a frame buffer that stores the image data of the previous frame. The NTSC encoder 18 encodes the input video data so that it can be watched through an NTSC broadcast TV and supplies it to the TV side. The voice decoder 15 separates the PES packet header from the voice packet, decodes and restores the bit string of the voice data, and sends the reconstructed voice data (Audio) to the speaker. On the other hand, the microcomputer 11 is the data stored in the smart card unit 19 according to the data request signal stored in the smart card unit 19 of the additional data separated from the system decoder 13, that is, the user's viewing qualifications, paid channels The data such as the viewing record and the like are read out and output to the modem unit 20. The module 20 transmits the data received from the microcomputer 11 to the management center through the telephone line.

As such, digital Mugunghwa satellite broadcasting in Korea is transmitted by multiplexing programs, data, resource and subscriber management system (RSMS) for managing subscribers and systems, and program guide information. In addition, PSI information necessary for demultiplexing such information is also transmitted. In addition, the PAT and PMT have connection information for program guides, RSMS messages, and so on. That is, the specific program number of the PAT has a PID for the RCM message in the RSMS message. Since the contents of the fields in the PAT and PMT are different according to the use environment, the information decoding of the PAT and PMT should be performed in the microcomputer.

Therefore, in the present invention, in selecting and decoding a desired program among a plurality of programs encoded and multiplexed in a digital satellite broadcast receiver, a selection program of a digital satellite broadcast receiver capable of processing PSI information such as PAT and PMT more efficiently in a microcomputer. The present invention provides a decoding method.

Another object of the present invention is to provide an apparatus for implementing the above-described method of decoding the selected program of the digital satellite broadcast receiver.

In order to achieve the above object, the selected program decoding method of a digital satellite broadcasting receiver according to the present invention selects and decodes a desired program from a transport stream (TS) in which several programs are encoded and multiplexed in a digital satellite broadcast receiver. In the method of the present invention, a program map table (PMT) comprising a program number, a program number, a video signal and an audio signal corresponding to the program in the received TS bit string, and each PMT are formed in one table A first step of separating and storing PSI information of a PAT (Program Association Table); a second step of generating an interrupt when PSI information of one packet is stored in the first step; and an interrupt occurring in the second step. And a third step of checking whether the PSI information stored in the first step is read to form a complete section structure, and the third step. If the PSI information has a complete section structure in the step, the PID of each of the video and audio signals corresponding to the selected program is decoded by decoding the PSI information, and if not, the fourth step of releasing the interrupt of the second step, and the fourth step. And a fifth step of separating and decoding a packet corresponding to a program selected from the received TS bit string using the PID obtained in the step, into a video packet and a voice packet, respectively.

In accordance with another aspect of the present invention, a program decoding apparatus for a digital satellite broadcast receiver selects a desired program from a digital satellite broadcast receiver and a transport stream (TS) in which several programs are encoded and multiplexed and transmitted. In the decoding apparatus, a PMT (Program Map Table) consisting of a PID of each program number, a video signal and an audio signal corresponding to the program in a received TS bit string, and a PAT having one table of each PMT ( A system decoder that separates and outputs the PSI information of the Program Association Table, and separates and outputs the packets corresponding to the program selected by the PID obtained by interrupting the microcomputer into a video packet and an audio packet, and separates the system decoder from the system decoder. Decode and output video and audio data of one packet, respectively A memory unit for storing the PSI information separated from the system decoder, and a video and audio corresponding to a program number selected by the user by decoding the PSI information read from the memory unit when interrupted by the system decoder. And a microcomputer for obtaining the PID of each signal and outputting the PID to the system decoder.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing an apparatus for decoding a selected program of a digital satellite broadcasting receiver according to the present invention. As shown, the apparatus of the present invention is the same as the configuration of the receiver of FIG. 1, and merely decodes the memory unit 22 of the queue structure buffers and PSI information such as PAT or PMT or CAT. The microcomputer 23 and the system decoder 21 which interrupts the microcomputer 23 are configured to be included.

An operation of the apparatus for decoding a selected program of the digital satellite broadcast receiver according to the present invention configured as described above will be described in more detail with reference to FIG.

3 is a flow chart for explaining the operation of the device of FIG.

First, when the viewer selects a program through the microcomputer 23, the system decoder 21 is a PAT in the TS packet transmitted through the channel decoder (see FIG. 1), the PMT corresponding to the program, and the CAT Only data constituting the section is separated and stored in the memory unit 22. Here, the memory unit 22 may be configured as a buffer having a queue structure to increase data storage and control efficiency, and a buffer is allocated to each of PAT, PMT, or CAT. The system decoder 21 interrupts the microcomputer 23 when one packet, i.e., 188 bytes, is input to the memory unit 22, and decrypts PSI information such as PAT or PMT or CAT. To be performed. Therefore, it is possible to obtain an audio and video PID for the selected program. When an interrupt is generated from the system decoder 21, the microcomputer 23 reads and decodes the TS packet of the PSI stored in the memory unit 22, obtains a PID for the program, and outputs the PID to the system decoder 21. The system decoder 21 separates and outputs only the audio and video bit strings corresponding to the program selected by the viewer among the TS packets received using the PID received from the microcomputer 23. More specifically, the system decoder 21 inputs only the TS packets of the PSI into the memory unit 22 among the TS packets transmitted through the channel decoder (see FIG. 1) (step 301). In each corresponding buffer allocated in step 22). That is, only the data corresponding to the PAT or PMT section is stored in each of the PAT buffer or PMT buffer in the memory unit 22. The system decoder 21 interrupts the microcomputer 23 when one packet is stored (step 303). After the interrupted microcomputer 23 reads the data stored in the buffer in the memory unit 22 (step 304), the scramble related information such as the PID for the EMM message in the PAT or PMT or RSMS message is read from the data. It is checked if the table (CAT) section, which is a table, is completely stored in the buffer (step 305). As a result of the check, if the complete PAT or PMT or CAT section is in the buffer, the microcomputer 23 decodes the TS packet of the PSI to obtain an audio and video PID of the selected program (step 306). The microcomputer 23 terminates the interrupt if the complete PAT or PMT or CAT section is not in the buffer as a result of the check. The PSI TS packet is then checked for complete table entry and decrypted only when the complete table is stored in the buffer.

As described above, the present invention relates to a method for decoding a selected program of a digital satellite broadcasting receiver and an apparatus thereof, and the PAT or PMT or CAT section of a PSI required for selecting a desired program from among various programs that are encoded, multiplexed and transmitted is completely made. Since decoding is performed only when it is input, the program can be selected and decoded more efficiently.

Claims (5)

A device for selecting and decoding a desired program from a transport stream (TS) in which a plurality of programs are encoded and multiplexed in a digital satellite broadcasting receiver, the apparatus comprising: a program number and a video signal corresponding to the program in a received TS bit string And the PMT (Program Map Table) consisting of PID of each voice signal and the PSI information of PAT (Program Association Table) that forms each PMT as one table, and outputs them separately. A system decoder for separating and outputting a packet corresponding to a selected program into an image packet and an audio packet, respectively; A video / audio decoder for decoding and outputting the video and audio data of the packet separated by the system decoder; A memory unit for storing PSI information separated by the system decoder; And a microcomputer for decoding the PSI information read from the memory unit to obtain PIDs of video and audio signals corresponding to a program number selected by the user when an interrupt is generated by the system decoder, and outputting the PIDs to the system decoder. Selective program decoding device of a digital satellite broadcast receiver. The apparatus of claim 1, wherein the memory unit comprises buffers having a queue structure allocated to PSI, PAT, PMT, and CAT tables, respectively. 2. The apparatus of claim 1, wherein the system decoder generates an interrupt each time the PSI information of one packet is input to the memory unit. The system of claim 3, wherein when the interrupt occurs in the system decoder, the microcomputer checks whether the PSI information of the PAT, PMT, or CAT read out from the memory unit has a complete section structure. And deciphering and disabling interrupts if they do not have a complete section structure. A method of selecting and decoding a desired program from a transport stream (TS) in which a plurality of programs are encoded and multiplexed in a digital satellite broadcasting receiver, the method comprising: a program number and a video signal corresponding to the program in a received TS bit string And a first step of separately storing PSI information of a PMT (Program Map Table) including a PID of each voice preference and a PAT (Program Association Table) in which each PMT is formed into one table; A second step of generating an interrupt when the PSI information of one packet is stored in the first step; A third step of checking whether a complete section structure is read by reading PSI information stored in the first step when an interrupt occurs in the second step; A fourth step of decoding the PSI information in the third step to obtain a PID of each of the video and audio signals corresponding to the selected program by decoding the PSI information, and releasing the interrupt of the second step if the PSI information is not a complete section structure; and And a fifth step of separating and decoding a packet corresponding to a program selected from a TS bit string received using the PID obtained in the fourth step into a video packet and a voice packet, respectively.