KR100626951B1 - Broadcast channel tuning method of digital multimedia broadcasting system - Google Patents

Abstract

The present invention relates to tuning a broadcast channel in a digital multimedia broadcasting system. To this end, in order to tune a broadcast channel in a digital multimedia broadcasting system, the conventional method of starting tuning only when a PAT of a corresponding broadcast channel transmitted at a predetermined period is received. Unlike this, the transport stream received in the digital multimedia broadcasting system is classified and buffered by PID, the PAT is received in the transport stream to extract a PMT PID having a PID value of 0, and the PID and ES_ID mapping information are extracted according to the PMT. After reconstructing the transport stream for each PID buffered according to the PID and ES_ID mapping information and the stream information, and tuning the selected broadcast channel according to the reconstructed transport stream, the broadcast channel is tuned regardless of the reception of the PAT in the digital multimedia broadcasting system. This can reduce the tuning time.

Description

Broadcast channel tuning method of digital multimedia broadcasting system {METHOD FOR TUNING BROADCASTING CHANNEL OF DIGITAL MULTIMEDIA BROADCASTING SYSTEM}

1 is a block diagram of a digital multimedia broadcasting system suitable for tuning a broadcast channel by buffering and reconstructing a transport stream for each PID according to the present invention;

2 is a flowchart illustrating a process of classifying and buffering transport streams by PID in a digital multimedia broadcasting system according to the present invention, and reconstructing them according to PAT and PMT;

3 is a diagram illustrating buffering classified transport streams by PID according to the present invention;

4 is a diagram illustrating reconstruction of a buffered transport stream according to PAT and PMT according to the present invention;

5 is a flowchart illustrating a process of reproducing a broadcast signal by tuning according to a reconstructed transport stream when a broadcast channel is changed in a digital multimedia broadcasting system according to the present invention.

<Description of the symbols for the main parts of the drawings>

102: key input block 104: control block

106: tuning block 108: demultiplexer block

110: buffer memory 112: decoding block

The present invention relates to a method for tuning a digital broadcasting channel in a digital multimedia broadcasting system. More particularly, the present invention relates to a digital program according to a program association table (PAT) and a program map table (PMT) included in a transport stream in a digital multimedia broadcasting system. A broadcast channel tuning method of a digital multimedia broadcasting system suitable for tuning a broadcast channel.

As is well known, digital broadcasting includes digital terrestrial broadcasting, digital satellite broadcasting, and digital cable broadcasting, which digitally encodes a broadcast signal and transmits it to a satellite or terrestrial channel, which is viewed through a receiving device. Here, the receiving apparatus includes a digital multimedia broadcasting system such as a set-top box and digital multimedia broadcasting (DMB).

In the digital multimedia broadcasting system, the PAT and PMT packet information is transmitted at a predetermined period (for example, 500 ms) in the transport stream of the digital broadcast signal.

On the other hand, in the terrestrial DMB, the PAT contains information about only one program, that is, PMT PID information. PMT consists of IOD (Initial Object Descriptor) descriptor which contains Object Descriptor (OD) and Binary Format for Scene description (BIFS) information and descriptors that contain information about each stream. It consists of information defining a program by mapping a program number to a bitstream (ES) containing encoded video, audio and data.

The digital multimedia broadcasting system performs a demultiplexing process on a transport stream to tune a broadcast channel to be watched according to the PAT and PMT information, and to reproduce the tuned digital broadcast signal.

Meanwhile, in the related art, a method for tuning a digital broadcast channel in a digital multimedia broadcasting system receives a PAT for a broadcast channel that a user wants to watch among PATs transmitted in a predetermined period (for example, 500 ms, etc.) on a transport stream, thereby adjusting PID values. It extracts PMT PID that is 0, and extracts PID and ES_ID (Elementary Stream IDentifier) mapping information for each transport stream according to the PMT, and extracts IOD, OD, and BIFS information according to PID and ES_ID mapping information for each transport stream. A corresponding broadcast signal is reproduced by decoding the corresponding bit stream. In this case, the IOD includes information on the OD stream and the information on the SD (Scene Descriptor) stream in the ES descriptor field, thereby connecting the BIFS and the OD of the SD. In addition, the IOD includes a stream type as a data type and an identification number of a packet corresponding to the stream type, that is, an ES_ID which is a logical channel.

However, in the conventional method of tuning a digital broadcast channel, since the PAT is transmitted at a predetermined period (for example, 500 ms, etc.) on the transport stream, the PAT is decoded only after receiving the PAT for the desired broadcast channel. By tuning and reproducing a broadcast channel corresponding to the bitstream in accordance with the mapping information, there is a problem that the tuning time is further increased by a predetermined time interval.

Accordingly, the present invention is to solve the above problems of the prior art, by buffering and reconstructing the transport stream for each PID in the digital multimedia broadcasting system for each PID, by using this to tune the selected broadcast channel regardless of the reception of the PAT An object of the present invention is to provide a broadcasting channel tuning method of a digital multimedia broadcasting system capable of reducing a tuning time.

In order to achieve the above object, the present invention provides a method for tuning a digital broadcasting channel in a digital multimedia broadcasting system, comprising: classifying and buffering a received transport stream for each PID, receiving a PAT from the transport stream, Extracting a PMT PID of 0, extracting PID and ES_ID mapping information according to the PMT, reconstructing a transport stream for each PID buffered according to the PID and ES_ID mapping information, and stream information; A broadcast channel tuning method of a digital multimedia broadcasting system comprising tuning a selected broadcast channel according to a transport stream.

The above and other objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

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

In order to tune a broadcast channel in a digital multimedia broadcasting system, a key technical aspect of the present invention is that unlike a conventional method in which tuning starts only when a PAT of a corresponding broadcast channel transmitted at a predetermined period is received, a transport stream received in a digital multimedia broadcasting system Classify and buffer by PID, extract PMT PID with PID value 0 by receiving PAT in transport stream, extract PID and ES_ID mapping information according to PMT, and buffer according to PID and ES_ID mapping information and stream information By reconfiguring the transport stream for each PID and tuning the selected broadcast channel according to the reconstructed transport stream, it is easy to achieve the object of the present invention through such technical means.

FIG. 1 is a block diagram of a digital multimedia broadcasting system suitable for tuning a broadcast channel by buffering and reconstructing a transport stream for each PID according to the present invention, and includes a key input block 102, a control block 104, and a tuning block 106. , Demultiplexer block 108, buffer memory 110, and decoding block 112.

Referring to FIG. 1, the key input block 102 generates an operation signal for controlling an operation of a digital multimedia broadcasting system, including a keypad, a remote controller, and the like, for example, an input means of which a user is not shown. For example, when a key for changing a broadcast channel is input using a keypad, a remote controller, or the like, a channel change manipulation signal is generated and transmitted to the control block 104 in response to the input.

In addition, the control block 104 performs a general operation control of the digital multimedia broadcasting system, including a microprocessor, for example, and a control signal for tuning and demodulating any one of broadcast channels received through an antenna. To the de-multiplexer block 108 to provide to the tuning block 106 and to separate and transmit the demodulated broadcast signal (transport stream) into the video signal, the audio signal and the data. Decoding the signal to provide a control signal for decoding through the monitor and speaker not shown to the decoding block 112, and the like.

In addition, the control block 104 provides a demultiplexer block 108 and the buffer memory 110 to buffer the PID for the received transport stream for each PID, and when the PAT is received in the transport stream, the PID value is 0. A demultiplexer block 108 and a buffer memory provide control signals for extracting the PMT PID to the demultiplexer block 108, and thus control signals for reconstructing the transport stream for each PID buffered according to the PID and ES_ID mapping information and the stream information. Provided by 110. The stream information here includes IOD, OD, BIFS, etc.

In addition, the control block 104 extracts the reconstructed transport stream when the broadcast channel is changed, and provides control signals for tuning the selected broadcast channel to the buffer memory 110 and the tuning block 106.

Next, the tuning block 106 tunes any one of the broadcast channels received through the antenna in response to the tuning control signal provided from the control block 104, demodulates the broadcast signal of the tuned broadcast channel and demultiplexes the block. Forward to 108. The tuning block 106 also tunes the selected broadcast channel according to the reconstructed transport stream provided from the control block 104.

The demultiplexer block 108 separates the demodulated broadcast signal (transport stream) into a video signal, an audio signal, and data, and transmits the video signal and the audio signal to the decoding block 112 and the data to the control block 104. .

In addition, the demultiplexer block 108 classifies the demodulated broadcast signal (transport stream) according to the control signal provided from the control block 104 for each PID and delivers it to the control block 104 to buffer the PAT. When the PMT PID with a PID value of 0 is extracted and transmitted to the control block 104.

Meanwhile, the buffer memory 110 temporarily stores a transport stream classified for each PID delivered from the control block 104, and reconstructs and temporarily stores a transport stream classified for each PID according to the extracted PID, ES_ID information, and stream information. Alternatively, the reconstructed transport stream is extracted and delivered to the control block 104.

Decoding block 112 then decodes the transmitted video and audio signals for playback via monitors and speakers not shown.

Next, in the digital multimedia broadcasting system having the above-described configuration, the received streams are classified and buffered for each PID, the PMT PID having a PID value of 0 is extracted according to the received PAT, and the PID for each transport stream A process of reconfiguring the transport stream buffered for each PID according to the ES_ID and the stream information will be described.

FIG. 2 is a flowchart illustrating a process of classifying and buffering a transport stream for each PID in a digital multimedia broadcasting system according to the present invention, and reconstructing it according to PAT and PMT.

Referring to FIG. 2, when a transport stream of a digital broadcast received in a digital multimedia system is received (step 202), the demultiplexer block 108 demodulates the broadcast signal (transport stream) according to a control signal from the control block 104. Are classified by PID and transferred to the control block 104, and the control block 104 temporarily stores (buffers) the transport stream classified by PID in the buffer memory 110 (step 204). As an example, FIG. 3 is a diagram illustrating buffering classified transport streams by PID according to the present invention.

When a PAT is received on the transport stream (step 206), the control block 104 decodes the received PAT to extract a PMT PID having a PID value of 0 (step 208). Here, the PAT is packet information providing PID information of a transport packet for transmitting a table describing a component of a program, and is composed of NIT, SDT, TDT, and PMT PID information for all transmitted bitstreams (ES). .

In addition, the control block 104 extracts the PID and ES_ID mapping information for each transport stream by decoding the PMT according to the extracted PMT PID (step 210). Here, the PMT is composed of information defining a program by mapping a program number to a bitstream (ES) including encoded video, audio, and data.

Subsequently, the control block 104 reconstructs and stores the transport stream for each PID temporarily stored in the buffer memory 110 according to the extracted PID, ES_ID mapping information, and stream information (step 212). Here, the stream information means IOD, OD, and BIFS. The IOD includes information about the OD stream and the SD (Scene Descriptor) stream in the ES descriptor field, thereby connecting the BIFS and the OD of the SD. Perform. In addition, the IOD includes a stream type as a data type and an identification number of a packet corresponding to the stream type, that is, an ES_ID which is a logical channel. As an example, FIG. 4 is a diagram illustrating reconstruction of a buffered transport stream according to PAT and PMT according to the present invention.

Accordingly, the digital multimedia broadcasting system classifies and buffers transport streams for each PID, extracts PMT PIDs having a PID value of 0 when PAT is received, and extracts PID and ES_ID mapping information for each transport stream according to PMT. The transport stream for each PID buffered according to the PID, the ES_ID, and the stream information can be reconfigured and stored.

Next, a process of extracting a reconstructed transport stream when a broadcast channel is changed in a state in which the transport stream is reconfigured and buffered according to PAT and PMT as described above, and decoding and reproducing the broadcast signal accordingly, will be described.

5 is a flowchart illustrating a process of reproducing a broadcast signal by tuning according to a reconstructed transport stream when a broadcast channel is changed in a digital multimedia broadcasting system according to the present invention.

Referring to FIG. 5, while reproducing a broadcast signal in a digital multimedia broadcasting system (step 502), the control block 104 uses a user input means (not shown), for example, a keypad, a remote controller, or the like, to control a broadcast channel. When a key to change is inputted, it is checked in response to the channel change operation signal generated in the key input block 102 (step 504).

As a result of the check in the step 504, if there is a channel change operation signal, the control block 104 extracts the reconstructed transport stream for the selected broadcast channel from the buffer memory 110 and provides it to the tuning block 106. (Step 506, 508).

Accordingly, the tuning block 106 tunes the selected broadcast channel according to the reconstructed transport stream provided from the control block 104, demodulates it, and forwards it to the demultiplexer block 108, where the video signal is demultiplexer block 108. In operation 510, the audio signal and the data are separated, and the decoding block 112 decodes the video signal and the audio signal through a monitor and a speaker (not shown).

Therefore, when the broadcast channel is changed while the digital multimedia broadcasting system is playing the digital broadcast signal, the transport stream for the selected broadcast channel may be extracted, tuned accordingly, and the broadcast signal of the tuned broadcast channel may be reproduced.

As described above, in order to tune a broadcast channel in the digital multimedia broadcasting system, the present invention, unlike the conventional method in which tuning starts only when a PAT of a corresponding broadcast channel transmitted at a predetermined period is received, is a transport stream received in the digital multimedia broadcasting system. Classify and buffer by PID, extract PMT PID with PID value 0 by receiving PAT in transport stream, extract PID and ES_ID mapping information according to PMT, and buffer according to PID and ES_ID mapping information and stream information After reconstructing the transport stream for each PID, the selected broadcast channel is tuned according to the reconstructed transport stream, so that the selected broadcast channel can be tuned and reproduced regardless of the reception of the PAT transmitted at a predetermined period in the digital multimedia broadcasting system.

Therefore, by tuning the selected broadcast channel according to the reconstructed transport stream in the digital multimedia broadcasting system, the tuning time can be reduced.

Claims (2)

A method of tuning a digital broadcast channel in a digital multimedia broadcasting system, Classifying and buffering the received transport stream for each PID; Receiving a PAT in the transport stream and extracting a PMT PID having the PID value of 0; Extracting PID and ES_ID mapping information according to the PMT; Reconstructing the transport stream for each PID buffered according to the PID and ES_ID mapping information and stream information; Tuning a selected broadcast channel according to the reconstructed transport stream Broadcast channel tuning method of a digital multimedia broadcasting system comprising a. The method of claim 1, The stream information, IOD, OD, BIFS broadcast channel tuning method for a digital multimedia broadcasting system characterized in that it comprises.

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