JP2001346109A - Channel selection method for digital broadcast receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital broadcast receiver that predicts identification information ES PID of video and audio data so as to speed up channel selection processing and enhance the response of a user operation. SOLUTION: The method of this invention includes an A/V identification information prediction process where video identification information, audio identification information, and identification information of time reference information included in a received digital broadcast wave are obtained and an A/V tentative reproduction process where the reproduction preparation of video and audio data by using the information obtained in the A/V identification information prediction process for tentative decision identification information is conducted in parallel with reception processing of the information denoting a broadcast program and the information (PMT) denoting the relation of PIDs being video and audio information sets by each broadcast program, and video format detection, PCR reproduction processing and A/V synchronization processing are conducted beforehand. After confirming that the identification information predicted by the A/V identification information prediction process is correct, the A/V tentative reproduction process immediately outputs video and audio data which are ready.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for selecting a digital broadcast receiver, and more particularly to a method for selecting a carrier and a transponder, obtaining video and audio identification information from broadcast waves, and outputting video and audio. It is related to a tuning method.

[0002]

2. Description of the Related Art In digital broadcasting, the contents of one or a plurality of broadcast programs are compressed by an MPEG2 encoder, and the video and audio of the broadcast programs are respectively compressed by PI.
Numbered by any identifying information called D,
Each PID is packetized into a 188-byte configuration called a transport packet (TP) and transmitted in a time-division manner. This set of TPs is called a transport stream (TS).

In order to view a desired broadcast program, a transport packet (TP) in which one or a plurality of broadcast programs are multiplexed constitutes a video and audio transport packet to be viewed and a broadcast program. It is necessary to extract a transport packet (TP) of program specification information, called PSI, which contains information indicating the relevance of PID, which is identification information of video and audio.

[0004] Information indicating a currently transmitted broadcast program is called a PAT (Program Association Table), and information indicating the relevance of PID, which is video and audio identification information for each broadcast program, is called a PMT (Program MapTable).

[0005] Inside the PAT, all broadcast programs currently being sent are stored, and one broadcast program is composed of:
It is identified by a program number, and has a one-to-one correspondence with a PMT that contains detailed information of the broadcast program.

[0006] In the PMT, ES information such as video identification information (Video Stream PID), audio identification information (Audio Stream PID), and time reference information identification information (PCR PID) related to a corresponding broadcast program is provided. Contains PID (Elementary PID).

Therefore, in order to view a broadcast program, first, a PAT, which is PSI information, is obtained, a PMT corresponding to the broadcast program desired to be viewed is received, video identification information (Video stream PID), audio identification information, and so on. (Audio Str
eam PID), PCR (Program Clock Referenc) that stores time information that is a reference time for reproducing video and audio
e) The identification information (PCR PID) is obtained.

When the reproduction of the video and audio of the broadcast program obtained from the PSI is started, the video and the audio are not synchronized at the same time because the video and the audio are not output simultaneously.

Therefore, in order to synchronize video and audio,
The PCR value that is the reference time and the PL that the receiver has
After synchronizing the oscillation speed of the L clock, the reproduction time PT of the video stream and the audio stream respectively
P that the receiver has S (Presentation Time Stump)
Synchronize with the value counted up by the LL clock.

Further, in recent digital broadcasting, there is a case where a different video format is transmitted for each broadcast program. In this case, the digital broadcast receiver detects the video format and displays the video on the receiver. The circuit settings need to be adjusted to the received video format. Note that in order to acquire the video format, the Sequence added to the video stream at regular intervals
You must refer to the contents of the Header.

The channel selection time in a digital broadcast receiver is mainly the time from setting of the tuner unit to tuning, PAT / PMT reception waiting time, video format information detection time, and A / V synchronization. (Lip sync processing).

The time excluding the time from the setting of the tuner unit to the tuning out of the time elements of the channel selection processing is for receiving information necessary for each processing from the transport stream (TS). The retransmission cycle of necessary information largely depends on the time.

That is, the time required for the channel selection process (channel selection time) is given by the following equation: tuning time = tuning time of tuner section + PAT retransmission cycle + PMT retransmission cycle + Sequence Header retransmission cycle As described above, the retransmission cycle of necessary information largely depends on the time.

As an example of the retransmission cycle of each information, a US AT
SC standard (United States Advanced Television Committe
In e), the retransmission time of each information is defined as follows: PAT retransmission cycle = 100 ms PMT retransmission cycle = 400 ms Sequence Header transmission cycle = 500 ms If the receiver conforms to this broadcasting standard, PSI reception It can be easily estimated that it takes about 1 second from processing to output of video and audio.

[0015]

However, according to the conventional channel selection method, video identification information (Video Stream PID)
And the audio identification information (Audio Stream PID), wait for the reception of the PAT, and then wait for the reception of the PMT.
After the reception of the MT is completed, the output processing of the video and the audio starts, so that the time required for acquiring the PAT and the PMT accounts for a large proportion of the entire tuning time.

Further, according to the conventional tuning method, the sequential processing is performed while waiting until necessary information can be obtained, so that the efficiency of the tuning processing cannot be increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a tuning method that speeds up the tuning process and improves the responsiveness of a user operation.

[0018]

In order to achieve the above object, a method of selecting a channel in a digital broadcast receiver according to the present invention is to provide a channel number or program number of a desired broadcast program or information for identifying a broadcast program. The video identification information (Video Stream PID) and audio identification information (A
udio Stream PID) and time reference information identification information (PCR PID)
A / V identification information prediction process for obtaining In addition, the video identification information (Video Stream PID) and the audio identification information (Audio Strea) obtained in the A / V identification information prediction process.
m PID) and the identification information of the time reference information (PCR PID) as the identification information of the provisional decision, the preparation of the reproduction of the video and audio, the reception processing of the information (PAT) indicating the broadcast program, and the video and audio of each broadcast program An A / V provisional playback process is performed in parallel with the reception process of information (PMT) indicating the relevance of the PID as identification information, and performs video format detection, PCR playback process, and A / V synchronization process in advance. I do. Then, the identification information obtained in the A / V identification information prediction process and the PA
A / A for comparing T with the identification information obtained from the PMT
By providing the V identification information comparison step, it is possible to confirm that the identification information predicted in the A / V identification information prediction step is correct, and to immediately output the video and audio which are already prepared from the A / V provisional reproduction step. Output.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a digital broadcast receiver to which an embodiment of a channel selection method according to the present invention is applied.

In FIG. 1, reference numeral 10 denotes a receiving antenna;
Denotes a remote control light receiving unit, 12 denotes a video output terminal, 13 denotes an audio output terminal, 100 denotes a tuner unit, 101 denotes a digital demodulator for demodulating a signal input from the tuner unit 100 into a digital signal (TS) and performing error correction. An error correction unit, 102 is a channel selection instruction unit that receives a channel selection instruction from a user, 103 is a demultiplexer that separates a digital signal into video data, audio data, and PSI data, and 104 is a unit that decodes video data into a video signal. A video decoder 105, an audio decoder 105 for decoding audio data into an audio signal, a PSI analysis unit 106 for expanding and analyzing PSI information, and 107 a channel selection instruction unit 102 and P
Demultiplexer 1 based on information from SI analysis unit 107
03 is a channel selection control unit that switches the output video PID and audio PID, 108 is a video display control unit that controls the output of video signals, and 109 is an audio output control unit that controls the output of audio signals.

FIG. 2 is a flowchart showing the flow of the channel selection processing according to the present embodiment. The channel selection method of the present embodiment will be described along this processing flow.

First, a tuning process is started by an instruction from the tuning instruction unit 102 (step S200).

Next, in the process of stopping the A / V output in step S201, there is a possibility that the video and audio information may be changed in the course of the channel selection operation and the video and audio may be disturbed. Stop outputting video and audio signals.

Next, the tuner setting in step S202,
In the tuning process (tuner setting, carrier detection process), a frequency to be set for tuning is obtained based on the channel number specified by the channel selection instruction unit 102, and the frequency is set to the tuner unit 100. Wait until it detects that it has tuned to the broadcast wave.

By tuning the tuner unit 100,
The received signal is decoded into digital data by the digital demodulation / error correction unit 101, and the digital signal starts flowing to the demultiplexer 103.

As a result, in the PAT receiving process of step S203, an instruction for PAT receiving processing is issued, and then, in the PAT analyzing process of step S204, the PAT receiving process is performed.
The I analysis unit 106 expands and analyzes the received PSI information to determine the PMT of the PMT.

Step S205 following step S204
In the PMT receiving process of (1), the tuning control unit 107 instructs the PSI analyzing unit 106 to perform a PMT receiving process,
The PMT received by the analysis unit 106 is expanded and analyzed in a PMT analysis process S206 in the next step S206, and the PID of the Audio Stream and the PID of the Video Stream are analyzed.
And identification information (PCR PID) of the time reference information are obtained.

On the other hand, in parallel with the above-described processing from the PAT receiving step (step S203) to the PMT analyzing step (step S206), the following A / V identification information prediction step (step S207) starts the A / V provisional reproducing step. (Step S2
08) are performed simultaneously.

That is, in the A / V identification information prediction process of step S207, the Audio Stream PID, Vides
Stream PID and PCR PID prediction processing is performed, and ES PID (Elen
entary PID) is required.

Step S208 following step S207
In the A / V provisional regeneration process, the ES PID (Elementar
y PID) is registered in the demultiplexer 103, and the video and audio bit stream data on which the PID filtering has been performed by the demultiplexer 103 are stored in the video decoder 104 and the audio decoder 10 respectively.
Start flowing to 5.

When the bit stream data starts flowing to the video decoder 104 and the audio decoder 105, acquisition of video format information, adjustment of set values of a video display system, and A / V synchronization processing are performed. However,
At this time, the output from the video display control unit 108 and the audio output control unit 109 to the output terminals 12 and 13 is not performed.

The above-mentioned A / V provisional reproduction step (S208),
When the process of the PMT analysis process (S206) is completed,
In the A / V identification information comparison process of step S209,
Determined by the PMT analysis process (step S206)
The ES PID (Elementary PID) and the ES PID (Element obtained by the A / V identification information prediction process (step S207)
ary PID) to determine whether the result of the A / V identification information prediction process (step S207) is correct.

A / V identification information comparison process (step S20)
As a result of comparison of ES PID (Elementary PID) according to 9), if they match, an A / V identification information prediction process (step S20)
It can be determined that the result of 7) was correctly predicted. As described above, as a result of the comparison of the ES PID (Elementary PID) in the A / V identification information comparison process (step S209), if the two match, the A / V provisional reproduction process (step S208) previously Since it is ready to output the audio, the process immediately shifts to the A / V output start process in step S211 to immediately output the video signal to the video output terminal 12 and the audio signal to the audio output terminal 13, respectively.

If the ES PID (Elementary PID) comparison result in the A / V identification information comparison step (step S209) does not match, the result of the A / V identification information prediction step (step S207) is It is determined that the prediction was not correct, and the process proceeds to the A / V regeneration preparation process of step S210. In the A / V regeneration preparation process (step S210), the ES PID (Elementary PID) obtained in the PMT analysis process (step S206) is demultiplexed by the demultiplexer 103.
And the bit stream data of the video and audio that has been subjected to the PID filtering by the demultiplexer 103 starts to flow to the video decoder 104 and the audio decoder 105, so that the video format information can be obtained, the setting value of the video display system can be adjusted, A / V synchronization processing is performed. After waiting for the completion of the A / V regeneration preparation process (step S210), the process proceeds to step S2.
In the process of starting the A / V output of 11, the video signal is output to the video output terminal 12 and the audio signal is output to the audio output terminal 13.

Thus, the tuning process is completed in step S212.

Next, an example of a prediction method performed in the A / V identification information prediction step (step S207) of FIG. 2 will be described.

ATSC DIGITAL TELEVISION STANDARD A / 53
Based on the example defined in “5.3 The program paradigm”, the video and audio PIDs are obtained by the channel number specified at the time of tuning.

ATSC DIGITAL TELEVISION STANDARD A / 53
According to “5.3 The program paradigm”, PMT PID, VID
The following are examples of EO PID, AUDIO PID, and PCR PID.

First, base PID = program number≪
4 ・ PMT PID = base PID + 0 × 0000 ・ VIDEO PID = base PID + 0 × 0001 ・ PCR PID = base PID + 0 × 0001 ・ AUDIO PID = base PID + 0 × 0004 According to this example, ATSC is compliant. If the broadcast signal is a broadcast signal, various PIDs can be predicted by obtaining the Program Number without acquiring the PAT / PMT.

According to this prediction method, when the channel number for identifying the broadcast program of the U.S. terrestrial broadcast (DTV) is "35.03", the DTV uses "35".
Is a channel number for identifying an RF frequency in which a broadcast wave is carried, and is used for setting a tuner unit.

"03" is "Program Number",
It is used as a number for identifying a broadcast program carried in the same RF frequency band. Program Number "
Based on 03 ″, various identification information can be predicted as follows according to the range of the ATSC standard.

PMT PID = 0 × 0030 VIDEO PID = 0 × 0031 PCR PID = 0 × 0031 AUDIO PID = 0 × 0034 In this prediction method, the present invention is based on the US terrestrial information (DT)
Although shown as a specific example when applied to V), the prediction method is not limited to this example, and the prediction method according to the digital broadcasting standard to which the present invention is applied without departing from the spirit of the present invention. The method should be changed.

FIG. 3 is a flowchart showing a conventional general channel selection method without using the channel selection method of the above-described embodiment. Steps S301 to S306 in FIG. 3 are the same as steps S201 to S206 in FIG. 2, step S307 in FIG. 3 is the same as step S210 in FIG.
Steps S308 and S309 in FIG.
211 and S212. That is, in the conventional general channel selection method shown in FIG. 3, the step S shown in FIG.
The fact that there is no processing of 207, S208, and S209 is different from the channel selection method of the embodiment of the present invention.

FIG. 4 is a time chart showing a comparison between a channel selection time according to the conventional method and a channel selection time according to the channel selection method according to one embodiment of the present invention.

In FIG. 4, reference numerals 400 to 404 indicate elapsed times according to the conventional channel selection method.
06 shows the elapsed time by the channel selection method according to the embodiment of the present invention.

As can be seen from FIG. 4, the progress of the channel selection process has substantially the same number of steps in each of 300 to 304 and 400 to 406.
In the prediction process of No. 3, the output preparation of the display system and the audio system can be advanced, so that the conventional channel selection method of 400 to
The channel selection process can be completed in a time obtained by adding the process of 505 to the process up to 402.

[0047]

As described above, according to the present invention, in a digital broadcast receiver, channel selection processing can be efficiently performed in a shorter time, and the responsiveness of a user operation can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a digital broadcast receiver to which a tuning method according to an embodiment of the present invention is applied.

FIG. 2 is a flowchart showing a flow of a tuning process according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a flow of a conventional general tuning process.

FIG. 4 is a time chart showing a comparison between the time of the conventional tuning process and the tuning time of the tuning process according to one embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 receiving antenna 11 remote control light receiving section 12 video output terminal 13 audio output terminal 100 tuner section 101 digital demodulation / error correction section 102 tuning selection section 103 demultiplexer 104 video decoder 105 audio decoder 106 PSI analysis section 107 tuning control section 108 video Display control unit 109 Audio output control unit S200 Tuning process start S201 A / V output stop process S202 Tuner setting and tuning process S203 PAT reception process S204 PAT analysis process S205 PMT reception process S206 PMT analysis process S207 A / V identification information prediction process S208 A / V provisional reproduction process S209 A / V identification information comparison process S210 A / V reproduction preparation process S211 A / V output start process S212 Tuning process completion S300 Tuning process start S 01 A / V output stop process S302 Tuner setting and tuning process S303 PAT reception process S304 PAT analysis process S305 PMT reception process S306 PMT analysis process S307 A / V reproduction preparation process S308 A / V output start process S309 Tuning process completion 400 selection Station processing start 401 PAT reception process 402 PMT reception process 403 A / V reproduction preparation process 404 Tuning process completion 500 Tuning process start 501 PAT reception process 502 PMT reception process 503 A / V identification information prediction process 504 A / V temporary reproduction Step 505 A / V identification information comparison step 506 Channel selection processing completed

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/081

Claims (5)

[Claims] 1. A desired broadcast program is detected from a digital broadcast wave obtained by multiplexing at least one broadcast program, and video identification information (Video Stream PID), audio identification information (Audio Stream PID), and identification information of time reference information are detected. (PC
R PID), which is a channel selection method for reproducing video and audio. The channel number or program number of a desired broadcast program, or information for identifying a broadcast program, is included in a received digital broadcast wave. Video identification information (Video Stream PID) and audio identification information (Audio
A method for selecting a digital broadcast receiver, comprising an A / V identification information prediction process for obtaining identification information (PCR PID) of the stream reference and time reference information. 2. The method of selecting a digital receiver according to claim 1, wherein the video identification information (Video Stream PID) and the audio identification information (Audio St) obtained in the A / V identification information prediction process.
digital broadcast receiver characterized by having an A / V provisional reproduction process in which preparation for reproduction of video and audio is performed in advance using identification information (ream PID) and identification information (PCR PID) of time reference information as provisional determination identification information. Tuning method. 3. The method of selecting a digital broadcast receiver according to claim 2, wherein the operation of the A / V identification information prediction step and the A / V provisional reproduction step and information of a broadcast program included in a digital broadcast wave are performed. A method of selecting a digital broadcast receiver, wherein the operation of the step of acquiring the channel is performed in parallel. 4. The method for selecting a digital broadcast receiver according to claim 2, wherein the video identification information (Video Stream PID) and the audio identification information (Audio S) obtained in the A / V identification information prediction step are obtained.
tream PID) and time reference information identification information (PCRPID)
Video identification information (Video Stream) obtained in the process of acquiring information on broadcast programs contained in digital broadcast waves
A for comparing PID), audio identification information (Audio Stream PID), and identification information (PCR PID) of time reference information.
/ V discriminating method for digital broadcasting receivers, comprising a step of comparing identification information. 5. The digital broadcast receiver tuning method according to claim 4, wherein the comparison results in the A / V identification information comparison step show that if the two identification information matches, the A / V provisional reproduction step is performed. A comparison between the process of immediately outputting video and audio based on the prepared reproduction and the A / V identification information comparison process reveals that if the identification information does not match, the broadcast program included in the digital broadcast is Prepares playback of video and audio based on video identification information (Video Stream PID), audio identification information (Audio Stream PID), and time reference information identification information (PCR PID) obtained in the process of acquiring information. A method for selecting a digital broadcast receiver, comprising: outputting a video and an audio.