JP4018823B2 - MPEG-2 broadcast program storage and playback system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for storing and playing back a program coded by an MPEG-2 system stored in a storage medium.
[0002]
[Prior art]
The MPEG-2 system standard (ISO / IEC 13818) provides a way to code a large number of programs. Each program consists of video, audio and data parts. According to the MPEG-2 system standard, data of multiple programs can be transmitted as a single time division multiplex transport stream.
[0003]
The basic unit of the transport stream is a transport packet. Each transport packet has a fixed length (ie, 188 bytes) and is composed of a header portion and a data portion. A PES packet can be formed by combining the data portions of multiple transport packets. Each PES packet can represent video, audio, or data for forming the program. A number of transport packets representing PES packets of other programs are interleaved. Therefore, the multiplex program can be transmitted in a time division manner. The transport stream transmits several system packets. System packets do not belong to any one program, but are used to associate each program with a transport packet.
[0004]
A transport stream including multiple programs is currently used in a direct broadcast satellite (DBS) system. In such a system, several programs to be transmitted through a normal broadcast channel are converted into a single transport stream and then transmitted through a transponder channel. The satellite service consists of several transponder channels. At the receiver, a specific transponder channel is selected and transport packets corresponding to a specific program are demultiplexed. Such a packet is provided to a decoder and converted into an analog video signal or an audio signal.
[0005]
Detect video and audio transport packets of a single program from a transport stream, store them on a storage medium such as a hard disk, digital VCR, or DVHS, then transfer these PIDs to the playback device for playback. Must be provided. However, at the time of reproduction, there is a problem that the reproduction apparatus cannot reproduce well because there is no PAT and PMT information for video and audio transport packets from the storage medium.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and an object of the present invention is to store and play back an MPEG-2 video / audio so that an MPEG-2 broadcast signal can be played back without PAT and PMT information. To provide an apparatus.
[0007]
It is another object of the present invention to provide an MPEG-2 video / audio storage and playback method capable of storing and playing back an MPEG-2 broadcast signal regardless of PAT and PMT.
[0008]
[Means for Solving the Problems]
  To achieve the above object, the MPEG-2 video / audio playback apparatus according to the present invention corresponds to the transport stream of the same MPEG-2 broadcast program and the PID of the input video and audio transport packets, respectively. Means for switching and storing the storage video PID and the storage audio PID; means for demultiplexing the transport stream from the storage means according to the set video and audio PID values; and the demultiplexing Means for detecting a sequence header from the video and audio bit strings from the means and decoding the video and audio bit strings based on the detected sequence header; and included in the transport bit string from the storage meansTwoIt comprises means for detecting a PID and providing the detected PID as a video PID and an audio PID to the demultiplexing means based on whether the decoding means detects the sequence header. It is characterized by that.
[0009]
  The MPEG-2 video / audio storage device according to the present invention is a means for generating a storage video PID and storage audio PID corresponding to an input video and audio transport packet; Means for switching to a storage video PID, switching the PID of the audio transport packet to the PID of the audio transport packet; and storing the video and audio transport packets with the PID replaced in a storage medium, respectively. Means.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.
[0013]
FIG. 1 is a block diagram of an MPEG-2 video / audio playback device according to an embodiment of the present invention connected to a conventional storage device.
[0014]
Referring to FIG. 2, an MPEG-2 video / audio playback apparatus according to an embodiment of the present invention includes a link unit 110, a multiplexer 120, a buffer 130, a demultiplexer 140, an MPEG decoder 150, a microcomputer 170, a storage device 180, and a keyboard 160. Consists of.
[0015]
The link unit 110 selects a reception channel according to a tuning control signal from the microcomputer 170. The link unit 110 channel-decodes a broadcast signal input through the reception channel to generate a transport stream, and outputs the generated transport stream to the multiplexer 120. The transport stream is obtained by multiplexing a large number of broadcast programs.
[0016]
The multiplexer 120 outputs any one of the transport stream from the link unit 110 and the transport stream 1801 from the storage device 180 described later to the buffer 130 in response to a control signal 1702 from the microcomputer 170.
[0017]
The buffer 130 buffers in response to the microcomputer control signal from the multiplexer 120.
[0018]
The demultiplexer 140 demultiplexes the transport stream from the buffer 130 under the control of the microcomputer 170. The demultiplexer 140 reads program specific information from the transport packet, for example, a program association table, a program map table, network information, and a conditional access table. A packet related to (Conditional Access Table) is detected, and the detected PSI-related packet is decoded and provided to the microcomputer 170. The demultiplexer 140 demultiplexes the transport stream using the PID provided by the microcomputer 170 and outputs a bit string of transport packets of each program. For example, when the microcomputer 170 provides a video and audio PID of a certain broadcast program, the demultiplexer demultiplexes the transport stream according to the video and audio PID, and the video transport stream and audio of the broadcast program. Generate a transport stream.
[0019]
The MPEG decoder 150 decodes the single video transport stream and the single audio transport stream from the demultiplexer 140 to generate a video signal and an audio signal, respectively. Provide to a display device (not shown). When decoding the video transport stream, the MPEG decoder 150 according to the present invention detects a sequence header during the initial sequence period, and provides the microcomputer 170 with a result of the presence or absence of the detection.
[0020]
The keyboard 160 is operated by a user. The user selects a broadcast program through the keyboard 160 or selects a recording and playback mode. The command signal selected through the keyboard 160 is provided to the microcomputer 170.
[0021]
The microcomputer 170 controls the entire apparatus in response to a command signal from the keyboard 160. When any one broadcasting station is selected by the keyboard 160, the microcomputer 170 transmits a transport stream including the selected broadcasting program based on the PAT provided from the demultiplexer 140. The link unit 110 is controlled so that the link unit 110 receives the transmission channel. The microcomputer 170 detects the PID of the transport packet of the selected broadcast program from the PMT from the demultiplexer 140, that is, the video and audio PID of the selected broadcast program, and detects the detected video and audio. The PID is provided to the demultiplexer 140.
[0022]
In the recording mode, the microcomputer 170 codes the audio and video transport packets output from the demultiplexer 140 and then provides the packets to the storage device 180, and the audio and video transport packets coded using the storage device. Is recorded on the tape or disk 183.
[0023]
In the playback mode, the microcomputer 170 causes the storage device 180 to read the transport stream stored on the tape or disk 183. The microcomputer 170 controls the multiplexer 120 to cause the multiplexer 120 to output the transport stream from the storage device 180. The microcomputer 170 detects the PID of the transport packet stored in the buffer 130 and provides the detected PID to the demultiplexer 140 as a video and audio PID. The microcomputer 140 determines whether the video and audio PID settings of the demultiplexer 140 are correct based on the detection result. If the video and audio PID settings are not correct as a result of the determination, the microcomputer 170 changes the video PID set in the demultiplexer 140 to the audio PID and the audio PID to the video PID.
[0024]
Hereinafter, the playback operation of the MPEG-2 video / audio playback apparatus configured as described above will be described in more detail with reference to FIGS.
[0025]
FIG. 2 is a flowchart for explaining the operation of the microcomputer 170 of FIG. 1 in the reproduction mode.
[0026]
Referring to FIG. 2, when the user provides a reproduction command signal to the microcomputer 170 through the keyboard 160, the microcomputer 170 operates the recording / reading device 181 of the storage device 180 in step 1 to perform a tape or disk 185. The data stored in is read. The data stored on the tape / disk 183 is a transport packet of a single broadcast program. The transport stream output from the recording / reading device 181 is provided to the multiplex 120. At this time, the microcomputer 170 causes the multiplexer 120 to output the transport stream from the storage device 180 to the buffer 130 (ST1, ST2).
[0027]
In step 3, the microcomputer 170 reads the transport packet stored in the buffer, and detects the PID from the transport packet read in step 3 (ST3).
[0028]
In step 4, the microcomputer 170 determines whether a predetermined number of PIDs are detected in step 3 (ST4).
[0029]
In step 5, when the detected PID is equal to or greater than a predetermined number, the microcomputer 170 transfers the detected PID to the transport so that the demultiplexer 140 can demultiplex the transport stream from the buffer 130. This is provided to the demultiplexer 140 as video and audio PID of the transport packet of the stream (ST5).
[0030]
If the number of detected PIDs is less than a predetermined reference number, the microcomputer 170 repeats steps 2 to 4.
[0031]
Next, the demultiplexing operation of step 5 will be described in more detail with reference to FIG.
[0032]
According to FIG. 3, in order to provide video and audio PIDs to the demultiplexer 140, the microcomputer 170 selects the two PIDs with the highest number of detections among the detected PIDs (ST31).
[0033]
The microcomputer 170 determines the same time as the sequence period as a timeout, and checks whether the MPEG decoder 150 detects the sequence header during the sequence period (ST32, ST33, ST34, ST35).
[0034]
When the MPEG decoder 150 detects a sequence header, the microcomputer 170 determines that the video PID and audio PID settings of the demultiplexer 140 are correct, and waits for the next command from the keyboard 160.
[0035]
If the MPEG decoder 150 does not detect a sequence header during the sequence period, the microcomputer 170 determines that the video PID and audio PID setting of the demultiplexer 140 is incorrect, and The video PID set in the multiplexer 140 is set as the audio PID, and the audio PID is set as the video PID (ST36).
[0036]
Thus, the device according to the invention can decode the transport stream read from the storage device without information on the video PID and the audio PID.
[0037]
FIG. 4 is a block diagram of an MPEG-2 video / audio storage device according to another embodiment of the present invention connected to a set top box.
[0038]
As shown in FIG. 4, an MPEG-2 video / audio storage device 400 according to an embodiment of the present invention is connected to a set top box 300 for receiving digital broadcasting through an interface device 390.
[0039]
The set top box 300 outputs an MPEG-2 broadcast signal received through an antenna (not shown) or a video and audio signal of a broadcast program selected by a user from a DVHS, DVCR, or HDD storage device.
[0040]
In general, the set top box 300 includes a link unit 310, a multiplexer 320, a first buffer 330, a demultiplexer 340, an MPEG decoder 350, a first microcomputer 370, and a keyboard 360.
[0041]
The link unit 310 selects a reception channel according to the tuning control signal of the first microcomputer 370. The link unit 310 channel-decodes a broadcast signal input through the reception channel to generate a transport stream, and outputs the generated transport stream to the multiplexer 320. The transport stream from the link unit 310 is obtained by multiplexing a large number of broadcast programs.
[0042]
The multiplexer 320 outputs one of the transport stream from the link unit 310 or the transport stream from the storage device 400 of the present invention, which will be described later, to the demultiplexer 340 according to the control signal from the first microcomputer 370. To do.
[0043]
The demultiplexer 340 demultiplexes the transport stream from the first buffer 330 under the control of the first microcomputer 370. The demultiplexer 340 detects program specific information from the transport packet from the multiplexer 320, for example, a packet associated with the program association table, program map table, network information, and conditional access table, and detects the detected PSI related packet. Is provided to the first microcomputer 370. The demultiplexer 340 demultiplexes the transport stream using the PID provided by the first microcomputer 370 and outputs a bit string of transport packets of each program. For example, when the first microcomputer 370 provides a video and audio PID of a broadcast program, the demultiplexer demultiplexes the transport stream using the video and audio PID, and a video transport stream of the broadcast program. And an audio transport stream.
[0044]
The MPEG decoder 350 decodes the single video transport stream and the single audio transport stream from the demultiplexer 340, respectively, to generate a video signal and an audio signal. Provide to a display device (not shown).
[0045]
The keyboard 360 is operated by a user. The user selects a broadcast program through the keyboard 360 or selects a recording and playback mode. The command signal selected through the keyboard 360 is provided to the first microcomputer 370.
[0046]
The first microcomputer 370 controls the entire set top box 300 in response to a command signal from the keyboard 360. When any one broadcast program is selected by the keyboard 360, the first microcomputer 370 generates a transport stream including the selected broadcast program based on the PAT provided from the demultiplexer 340. The link unit 310 is controlled so that the link unit 310 receives a transmission channel to be transmitted. The first microcomputer 370 detects the PID of the transport packet of the selected broadcast program from the PMT from the demultiplexer 340, that is, the video and audio PID of the selected broadcast program, and detects the detected video. And the audio PID to the demultiplexer 340.
[0047]
In the recording mode, the first microcomputer 370 outputs the audio and video transport packets output from the demultiplexer 340 to the interface device 390.
[0048]
In the reproduction mode, the first microcomputer 370 controls the multiplexer 320 so that a transport stream input from the storage device 400 through the interface device 390 is input to the demultiplexer 340. Further, the first microcomputer 370 sets the video PID and audio PID in the transport stream in the demultiplexer 340 so that the demultiplexer 340 can demultiplex the transport stream from the storage device 400. At this time, information regarding the video and audio PID of the transport stream is provided by the user through the keyboard 360 or stored in advance in a memory (not shown).
[0049]
The interface device 390 provides data from the set-top box 300 to the storage device 400 or provides data from the storage device 400 to the set-top box 300.
[0050]
The MPEG-2 video / audio storage device 400 according to the present invention responds to an external mode selection signal. When the storage mode is selected by the mode selection signal, the storage device 400 stores the video and audio transport streams input from the set top box 300 through the interface device 390 in a storage medium. When the playback mode is selected, the storage device 400 outputs video and audio data from the storage medium to the set top box 300 through the interface device 390 in the form of a transport stream.
[0051]
The storage device 400 may include a second microcomputer 410, a PID changer 420, a second buffer 430, an encoder 440, a storage 450, a decoder 460, and a third buffer 470.
[0052]
The second microcomputer 410 controls the storage unit 450 and the PID changer 420 in response to a mode selection signal from the outside. In the storage mode, the second microcomputer 410 provides the PID changer 420 with video or audio transport packets input from the demultiplexer 340 through the interface device 390. Then, a recording command signal is provided to the storage 450. In the reproduction mode, the second microcomputer 410 provides a reproduction command signal to the storage unit 450.
[0053]
The PID changer 420 changes the PID value of the video or audio transport packet from the second microcomputer 410 to a predetermined storage PID value, and stores the video or audio transport packet with the changed PID value in the second buffer 430. Output.
[0054]
The second buffer 430 buffers transport packets from the PID changer 420.
[0055]
The encoder 440 codes the transport packet bit string from the second buffer 430 so that the bit string can be stored in the storage medium by the storage 450.
[0056]
The storage 450 stores the coding signal from the encoder 440 in the storage medium in response to the storage command signal from the second microcomputer 410. In addition, when the reproduction command signal is input from the second microcomputer 410, the storage 450 reads data stored in the storage medium and outputs the data to the decoder 460.
[0057]
The decoder 460 generates a bit string of the transport packet by decoding the reproduction signal from the storage 450 and outputs the bit string to the third buffer 470.
[0058]
In addition, the second buffer 470 outputs the reproduction transport packet from the decoder 460 to the interface device 390.
[0059]
The operation of the MPEG-2 video / audio storage device 400 will be described below.
[0060]
FIG. 5 is a flowchart for explaining the operation in the storage mode of the MPEG-2 video / audio storage apparatus 400 of FIG.
[0061]
When the user selects the storage mode through the keyboard, the second microcomputer 410 detects PIDs of transport packets continuously input from the interface device 390. Also, the transport packet and the detected PID are provided to the PID changer 420 according to the input order (ST41, ST42).
[0062]
The second microcomputer 410 assigns a predetermined first stored PID value to the first transport packet, and the PID changer 420 changes the PID value of the first transport packet to the assigned first stored PID value. Then, the transport packet whose PID value is changed to the first stored PID value is output to the second buffer 430. Then, when a transport packet having a PID value different from the PID value of the first transport packet is input from the PID changer 420, the PID changer 420 assigns a second stored PID value to the transport packet, and After changing the PID value of the transport packet to the second stored PID value, the transport packet having the PID value changed to the second PID value is output to the second buffer 430 (ST43, ST44, ST45).
[0063]
The transport packet input to the second buffer 430 is provided to the encoder 440, coded by the encoder 440, and then recorded on the storage medium by the storage 450 (ST46).
[0064]
Accordingly, since the transport packet input through the interface device 390 is a video or audio transport packet of a single broadcast program, the storage device can store the video and audio information regardless of the type of the input broadcast program. Can be stored as two PID values.
[0065]
FIG. 6 is a flowchart for explaining the reproduction operation of the set top box 300 shown in FIG.
[0066]
According to FIG. 6, in the playback mode, the first microcomputer 370 controls the multiplexer 320 to input the transport stream from the interface device 390 to the demultiplexer 340 (ST51, ST52).
[0067]
Next, the first microcomputer 370 sets the PID value of the video transport packet of the transport stream from the interface device 390 to the first stored PID value, and the PID value of the audio transport packet to the second stored PID value. Each is set (ST53).
[0068]
The first microcomputer 370 sets a timeout time in step 54. At this time, the time-out period is preferably a sequence period (ST54).
[0069]
After setting the timeout time, the first microcomputer 370 determines whether the MPEG decoder 350 has detected a sequence header during the timeout time. At this time, if the MPEG decoder 340 detects a sequence header, the first microcomputer 370 determines that the video PID value and audio PID value set in step 53 are set correctly (ST55, ST56, ST57). ).
[0070]
If no sequence header is detected during the timeout period, the first microcomputer 370 determines that the video PID value and the audio PID value are incorrect, and sets the set audio and video PID values to each other. Replace and set (ST58). Then, the above steps 55 to 57 are executed again.
[0071]
Accordingly, the set top box 300 can be played regardless of how the first and second storage PIDs are assigned to the video and audio transport packets stored in the storage device 400.
[0072]
FIG. 7 is a view showing a set-top box incorporating the MPEG-2 video / audio storage device 400 of FIG.
[0073]
In FIG. 7, the same parts as those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0074]
In FIG. 7, the PID changer is directly connected to the demultiplexer 340. The output terminal of the third buffer 470 is connected to the multiplexer 320. The single microcomputer 701 serves as the first and second microcomputers 370 and 410 shown in FIG.
[0075]
【The invention's effect】
As described above, according to the present invention, the audio and video transport packets of one broadcasting program are changed to a predetermined recording PID and stored, or the video and audio PIDs from the transport stream packet to be read are stored. By detecting this, the stored program can be reproduced even if there is no PAT and PMT at the time of reproduction.
[0076]
The present invention has been described above based on the specific embodiments. However, the present invention is not limited to this, and it goes without saying that modifications and improvements can be made within the scope of ordinary knowledge of those skilled in the art. It is.
[Brief description of the drawings]
FIG. 1 is a block diagram of an MPEG-2 video / audio playback device according to an embodiment of the present invention connected to a normal storage device.
FIG. 2 is a flowchart for explaining an operation of the microcomputer of FIG. 1 in a reproduction mode.
FIG. 3 is a flowchart for explaining an operation of the microcomputer of FIG. 1 in a reproduction mode.
FIG. 4 is a block diagram of an MPEG-2 video / audio storage device according to another embodiment of the present invention connected to a set top box.
5 is a flowchart for explaining an operation in a storage mode of the MPEG-2 video / audio storage device of FIG. 4; FIG.
6 is a flowchart for explaining a playback operation of the set top box of FIG. 4;
7 is a diagram showing a set-top box incorporating the MPEG-2 video / audio storage device of FIG. 4; FIG.
[Explanation of symbols]
110, 310 Link section
120, 320 multiplexer
130 buffers
140, 340 Demultiplexer
150, 350 MPEG decoder
160, 360 keyboard
170 Microcomputer
180, 400 storage device
300 set-top box
330 first buffer
370 First microcomputer
390 Interface device
410 Second microcomputer
420 PID changer
430 Second buffer
440 Encoder
450 storage machine
460 decoder
470 Third buffer

Claims (3)

Means for storing the transport stream of the same MPEG-2 broadcast program by switching the PID of the input video and audio transport packets to the corresponding storage video PID and storage audio PID, respectively;
Means for demultiplexing the transport stream from the storage means according to the set video and audio PID values;
Means for detecting a sequence header from the video and audio bit strings from the demultiplexing means, and decoding the video and audio bit strings based on the detected sequence header; and the transport bit strings from the storage means 2 is detected, and based on whether the decoding means detects the sequence header, the detected PID is provided to the demultiplexing means as a video PID and an audio PID. Means of
An MPEG-2 video / audio playback apparatus comprising:   The apparatus further includes means for buffering the transport stream output from the storage means, the demultiplexing means demultiplexes the transport stream from the buffer means, and the PID providing means includes 2. The MPEG-2 video / audio playback apparatus according to claim 1, wherein the video PID and audio PID of the transport stream are detected based on transport packets of the transport stream stored in the buffer means. . Means for generating storage video PID and storage audio PID corresponding to incoming video and audio transport packets;
Means for switching the PID of the video transport packet to the storage video PID and switching the PID of the audio transport packet to the PID of the audio transport packet; and the video and audio transport packet with the PID replaced Means for storing each in a storage medium;
An MPEG-2 video / audio storage device comprising:

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