JP2002320180A - On-vehicle digital broadcast receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an on-vehicle digital broadcast receiver in which a program can be listened continuously, even when stoppage/start operation is repeated. SOLUTION: In a vehicle mounted digital broadcast receiver in which video packet or audio packet of a program designated by a user is taken out of a multiplex digital broadcast signal packetizing the video stream or audio stream of a plurality of programs and a video or audio is outputted, a digital broadcast receiving section 101 outputs the packet of a program designated by the user from a received digital broadcast signal; a recorder 103 records a packet outputted from the digital broadcast receiving section on a recording medium 102, regardless of the traveling state of a vehicle; and a reproducer 104 reads out the packet from the recording medium, when the vehicle is stopping and interrupts reading of the packet from the recording medium, when the vehicle is traveling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle digital broadcast receiving apparatus, and more particularly to a video of a program specified by a user from a digital broadcast signal in which video streams and audio streams of a plurality of programs are packetized and multiplexed. The present invention relates to an in-vehicle digital broadcast receiving apparatus that extracts a packet and an audio packet to output video and audio.

[0002]

2. Description of the Related Art In CS satellite digital broadcasting, MPEG-2
Digital broadcast receiving terminal installed at home via a network by multiplexing video / audio information of a plurality of programs and program arrangement information SI (Service Information) using TS (MPEG-2 transport stream) format as a logical format The subscriber receives the multiplex signal at the receiving terminal and enjoys the desired program. That is, the broadcasting station converts the program arrangement information SI and the video streams and audio streams of a plurality of programs into packets in the MPEG-2TS format, multiplexes the obtained packets, and
A TS transport stream is transmitted on a predetermined carrier.

[0003] The digital broadcast receiving apparatus appropriately displays a program guide screen based on the received program arrangement information SI, and a user selects a program to view. When a program to be viewed is selected, the digital broadcast receiving apparatus selects and demodulates a carrier on which the program is multiplexed, and the MPEG-2 TS (transport) in which packets of a plurality of television broadcast programs are multiplexed. After that, video packets and audio packets of a target television broadcast program are extracted from the transport stream, and the extracted video packets and audio packets are decoded to output video and audio.

[0004] Fig. 7 is an explanatory diagram of a case where an audio elementary stream Audio ES and a video elementary stream Video ES of one broadcast program are packetized and multiplexed, (1) is an audio elementary stream.
(Audio ES) and (5) are video elementary streams (Vi
deo ES), (2) are audio packets A1, A2, A3, A4, ... obtained by packetizing Audio ES, and (4) are video packets V1, V2, ... obtained by packetizing Video ES. .V1
1, .., (3) are multiplexed streams (MPEG-2 TS) obtained by time-division multiplexing of video packets and audio packets. 1
Since the amount of information per screen is larger in video than in audio, the multiplexed stream (3) has a configuration in which one audio packet is multiplexed with a plurality of video packets, and padding packets are inserted as appropriate. .

FIG. 8 is a diagram for explaining the structure of a packet.
o Although ES is shown, Video ES has the same configuration. Audio ES is divided into packet data of a predetermined size, and a PES header (PES:
Packetized Elementary Stream) is added to form a PES packet. The PES header includes a packet start code and playback output time management information PTS (Presentation Time Strategies).
amp), decoding time management information DTS (Decoding Time Stamp),
It includes a packet sequence counter PCS and the like. The PES packet is further divided into 184 bytes, each of which is prefixed with a 4-byte TS header and
A TS packet is formed. The TS header includes a unit start indication indicating that a PES header is included, and an audio ES identifier PI.
D (Packet ID) is included.

FIG. 9 is a table showing correspondence between names of various tables constituting the program arrangement information SI, packet identifiers PID, and table IDs. The tables include (1) PAT (Program Association Table), and (2) CAT (Conditional Access). (Table) (3) PMT (Program Map Table) (4) NIT (Network Information Table) (5) SDT (Service Description Table) (6) BAT (Bouquet Association Table) (7) EIT (Event Information Table) (8) TDT (Time Date Table) (9) RST (Running Status Table) (10) ST (Stuffing Table).

The first four tables PAT, CAT, PMT, NIT
Is a table defined by a ministerial ordinance and is called program specification information PSI (Program Specific Information). The functions of these tables are as follows. That is, (1) PAT designates the packet identifier (PID) of the TS packet transmitting the table PMT describing the configuration of each broadcast program, and (2) CAT designates the related information of pay broadcasting (decoding the scrambled program). (3) PMT transmits each coded signal (video signal, audio signal, etc.) that composes a broadcast program. One that specifies the identifier of the TS packet, (4) NIT transmits information that associates transmission path information such as the modulation frequency with the broadcast program, and (5) SDT is the name of the organization channel, the name of the broadcaster, etc. (6) BAT is the name of the bouquet (set of the organization channels), and indicates the information about the bouquet, such as the included channels, (7) EIT
Indicates information about the program, such as the program name, broadcast date and time, and a description of the contents of the program. (8)
TDT indicates the current date and time, (9) RST indicates the current progress status of the program, and (10) ST is a table indicating invalidation of the table.

FIG. 10 is an explanatory diagram of the hierarchical data structure of MPEG-2 TS PSI. The PAT (Program Association Table) is transmitted as a packet with the packet identifier PID = 0, and a table PMT (Prog.
Indicates the PID of the TS packet transmitting the ram map table. The figure shows that the identifier of the packet transmitting the PMT of the program (program) i is PID = Mi, and the identifier of the packet transmitting the PMT of the program j is PID = Mj. PMT indicates the identifier PID of the packet that transmits the video stream and audio stream that make up the program.
It is shown that the identifier of the packet transmitting the video stream of the program i is PID = Vi, the identifier of the packet transmitting the audio stream is PID = Ai, and the identifier of the packet transmitting the video stream of the program j is PID. = Vj, indicating that the identifier of the packet transmitting the audio stream is PID = Aj.

FIG. 11 is a block diagram of a conventional digital broadcast receiving apparatus, in which 11 is an antenna, 12 is a BS converter,
13 is a tuner pack (BS tuner), 14 is a demodulation / decoding section, 15 is a deinterleave / descrambling section, 16
Is a Reed-Solomon decoding unit, 17 is an MPEG separation unit, 18 is a video decoding unit, 19 is an audio decoding unit, and 20 is EPG data /
Basic data decoding unit, 21 is an image output unit, 22 is an audio output unit, 23 is a control unit, 24 is an operation unit, 25 is an EP
G image creation unit. EPG data is stored in an electronic program guide (Elect
ronic Program Guide), which is collected from the program sequence information SI and used for drawing the EPG screen.

The BS converter 12 converts a signal in the 12 GHz band to 1 GHz.
The signal is converted into a band BS-IF signal and supplied to a BS tuner at a required level. A tuner pack (BS tuner) 13 performs tuning control and quadrature detection based on a tuning command. The demodulation / decoding section 14 demodulates and decodes the interleaved / scrambled transmission data from the baseband signal output from the tuner, and the deinterleave / descramble section 15 de-interleaves and descrambles the input data. The Reed-Solomon decoding unit 16 performs error detection and correction processing on the input data to decode / output high-efficiency coded data (MPEG data), and the MPEG separation unit 17 outputs MPEG video data / MPEG audio data and EPG of the program selected by the user. Output data and basic data separately. The video decoding unit 18 decodes the MPEG video data, inputs a video signal to the image output unit 21, and
Decodes the MPEG audio data into PCM audio data, converts it into an analog audio signal, and inputs the analog audio signal to the audio output unit 22. The EPG data / basic data decoding unit 20 decodes the EPG data / basic data and controls the control unit 2
Enter 3

The control unit 23 has a microcomputer configuration.
While inputting the user's tuning information to the BS tuner 13,
The user-selected program information (PID) is input to the MPEG separation unit 17. Further, the control unit 23 accumulates EPG data, and inputs the EPG screen information to the EPG image creation unit 25 in response to a display request of the EPG screen. The EPG image creation unit 25 receives the EPG input from the control unit 23.
An EPG screen is created using the screen information and input to the image output unit 21. As described above, when a program to be received is selected, the digital broadcast receiving apparatus demodulates the carrier on which the selected program is multiplexed, and decodes the MPEG-2 TS (transformer) in which packets of a plurality of programs are multiplexed. (Port stream), video packets and audio packets of a target program are extracted from the transport stream, and the extracted video packets and audio packets are decoded to output video and audio.

[0012]

It is dangerous for a driver to watch television TV while driving. For this reason, it is designed not to display video images on the TV screen monitor while the car is running. With this design, there is a problem that a program that flows in real time during driving that repeats stopping / running can only be seen in a fragmentary manner, and the user cannot obtain sufficient information that the user wants. Also, in a tunnel, radio waves are often cut off and radio and television broadcasts cannot be viewed. For this reason, there is a problem in that when a user passes through a tunnel or a weak electric field area during radio reception, he or she misses the part that he / she wanted to view. Recently, a television TV is sometimes installed for a rear seat, but the same problem occurs in the case of a television TV. In view of the above, it is an object of the present invention to be able to continuously watch a program even during a driving operation in which the vehicle stops and runs repeatedly. Another object of the present invention is to allow a user to continuously watch a program even when a reception state deteriorates in a tunnel or the like and a packet is lost.

[0013]

SUMMARY OF THE INVENTION The present invention extracts video packets and / or audio packets of a program specified by a user from a digital broadcast signal in which video streams and / or audio streams of a plurality of programs are packetized and multiplexed. (1) a digital broadcast receiving unit that outputs a packet of a program specified by a user from a received digital broadcast signal, and (2) a recording device that records the packet on a storage medium. Device, (3) a playback device that reads, decodes, and outputs packets from the storage medium, and (4) has a running state detection unit that detects the running state of the vehicle.The recording device is a digital device regardless of the running state of the vehicle. The packet output from the broadcast receiving unit is recorded on a storage medium, and the playback device stops the vehicle. At this time, the reading of the packet from the storage medium is performed, and the reading of the packet from the storage medium is stopped when the vehicle is running. In this way, the video output can be stopped while the vehicle is running, and the program can be continuously viewed even during the operation in which the vehicle stops and runs repeatedly.

Further, the on-vehicle digital broadcast receiving apparatus of the present invention includes external communication means for requesting a broadcasting station to retransmit a lost packet, and the recording apparatus transmits the packet to a storage medium when the reception of the packet is interrupted. Stop recording, restart the recording of the packet to the storage medium when the reception of the packet is resumed, the playback device stops reading the packet from the storage medium when a loss is detected in the packet read from the storage medium, The external communication means requests the broadcast station to retransmit the missing packet, and the reproducing device decodes the retransmitted missing packet, outputs video and audio, and then resumes reading the packet from the storage medium. In this way, even if the reception condition deteriorates in a tunnel or the like and a packet is lost, the program can be viewed continuously by supplementing the missing packet from the broadcasting station.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (A) In-vehicle digital broadcast receiving apparatus FIG. 1 is a block diagram of an in-vehicle digital broadcast receiving apparatus according to the present invention, wherein 100 is an in-vehicle digital broadcast receiving apparatus, and 200 is a digital broadcasting station. . In the digital broadcast receiving apparatus 100, a digital broadcast receiving unit 101 extracts and outputs video packets and audio packets of a program designated by a user from a received digital broadcast signal, and has the same configuration as the digital broadcast receiving unit 10 in FIG. It has. Ten
Reference numeral 2 denotes a large-capacity storage medium for storing video packets and audio packets of a program desired by the user, preferably a storage medium which can be simultaneously recorded and read. 103 is a recording device for recording video / audio packets output from the digital broadcast receiving unit 101 on the large-capacity storage medium 102, 104 is a reproducing device for reading packets from the large-capacity storage medium 102, decoding and outputting the packets, and 105 is a video output Unit, 106 is an audio output unit, 107 is an operation unit, 108 is a running state detecting unit that detects the running state (running / stop state) of the vehicle, 109 is a control circuit that controls the whole, and 110 is retransmission of lost packets. Broadcasting station 2
00 is an external communication device such as a mobile phone.

When a program to be received is specified by the operation unit 107, the control circuit 109 inputs program information to the digital broadcast receiving unit 101 and activates the recording device 103 and the reproducing device 104. The recording device 103 continuously records the packets extracted by the digital broadcast receiving unit 101 on the large-capacity storage medium 102 as shown in FIG. 2 irrespective of the running state of the vehicle, and the reproducing device 104 stops (stops) the vehicle. Only when the vehicle is stopped, the packet is read from the large-capacity storage medium 102 in parallel with the recording, and when the vehicle is running, the reading of the packet from the storage medium is stopped. The control circuit 10 controls the start / stop of recording on the large-capacity storage medium 102 by the recording device 103 and the start / stop of reading from the large-capacity storage medium by the reproduction device 104.
9.

The recording device 103 stops recording the packet on the large-capacity storage medium 102 when reception of the packet is interrupted, for example, in a tunnel or while passing through a weak electric field area, and records the packet when reception of the packet is resumed. Also, the playback device 104 stops reading the packet from the large-capacity storage medium when a loss is detected in the packet read from the large-capacity storage medium, notifies the control circuit 109 of that fact, and notifies the control circuit 109 of the external communication. The device 110 requests retransmission of the missing packet to the broadcasting station 200 according to the instruction from the control circuit 109, and the playback device 104 decodes the missing packet retransmitted from the broadcasting station and outputs a video output and an audio signal. Reading of the packet is resumed.

(B) packet recording depending on the running state,
Reading Process FIG. 3 is a flowchart of a packet recording / reproducing process depending on a running state. The recording device 103 sequentially records video packets / audio packets of the program selected by the user, which are output from the digital broadcast receiving unit 101, on the large-capacity storage medium 102 (step 201). The control circuit 109 monitors the running state of the vehicle. If the vehicle is running, the readout prohibition signal is input to the playback device 104. If the vehicle is stopped due to parking or stopping, the readout permission signal is input to the playback device (step 202). If the playback device 204 is stopped, for example, a large-capacity storage medium according to the FIFO format
A video packet / audio packet is read from 102 and reproduced (step 203). On the other hand, if the vehicle is running, the next read position is stored (step 204), and the reproduction is interrupted.
(Step 205), and waits for the vehicle to stop. Thereafter, the processing of step 201 and thereafter is repeated. If writing is completed up to the end of the large-capacity storage medium 102, overwriting is performed from the beginning. The above is the case of recording / reproducing in accordance with the FIFO format. However, it is also possible to manage the reproduced area as a free area regardless of the FIFO format, and to effectively use the storage medium by writing in the free area.

(C) packet recording depending on the reception state,
Read Processing (a) Recording Processing Flow Dependent on Reception State FIG. 4 is a recording processing flow depending on the reception state. The digital broadcast receiving unit 101 monitors whether the reception of the packet is interrupted, extracts and outputs the video packet / audio packet of the program selected by the user if the reception is not interrupted, and stops the output of the packet if interrupted (step 301). . When a packet is output from the digital broadcast receiving unit 101, the recording device 103 records the packet in the large-capacity storage medium 102 in order (step 302), and when not output, stores the next recording position (step 303). ), Stop recording (step 30)
Four). As a result, packet loss occurs, and thereafter, the process returns to the beginning and waits for packet reception to resume. As described above, when the packet of the program being received is interrupted, such as when passing through a tunnel or a weak electric field area, the recording is interrupted, and the recording is resumed when the packet can be received through the area.

(B) First Reproduction Processing Flow When Packets Are Missing FIG. 5 is a first reproduction processing flow when packets are missing. The playback device 104 reads a packet from the next read position of the large-capacity storage medium 102 (step 401), decodes the packet (step 402), checks whether a packet is missing (step 403), and finds that there is no missing packet. If so, video / audio output is performed (step 404). On the other hand, if there is a packet loss, the reproduction is interrupted (step 405), the next read position is stored (step 406), and the missing packet ID is notified to the external communication device (mobile phone) 110 via the control circuit 109. (Step 407).

The external communication device 110 monitors whether or not the loss has been notified (step 451). If the loss is notified, the external communication device 110 accesses the broadcasting station 200 via the mobile network or the public network (step 45).
2), notify the broadcast station of the missing packet ID (step 45)
3). As a result, the broadcast station 200 transmits the requested missing packet, and the external communication device 110 receives the missing packet (step 454). Thereafter, the external communication device 110 inputs the received missing packet to the playback / playback device 104, and the playback device decodes the missing packet and outputs a video output and an audio output.
(Step 455) When the reproduction of the missing packet is completed (Step 456), the flow returns to Step 401, and the reading of the packet from the next reading position of the mass storage medium 102 is restarted. As described above, if the program being received is interrupted in a tunnel or when passing through a weak electric field area, the program from the interrupted part is obtained by obtaining the missing packet from the broadcasting station using a communication means such as a mobile phone. Reproduction becomes possible, and continuous viewing becomes possible.

(C) Second reproduction processing flow when a packet is lost FIG. 6 is a second reproduction processing flow when a packet is lost. The playback device 104 reads a packet from the next read position of the large-capacity storage medium 102 (step 501), decodes the packet (step 502), checks whether a packet is missing (step 503), and finds that there is no missing packet. If so, video / audio output is performed (step 504). On the other hand, if there is a packet loss, the reproduction is interrupted (step 505), the next read position is stored (step 506), and the missing packet ID is notified to the external communication device (mobile phone) 110 via the control circuit 109. (Step 507).

The external communication device 110 monitors whether or not the loss has been notified (step 551). If the loss has been notified, the external communication device 110 accesses the broadcasting station 200 via a mobile network or a public network (step 55).
2), Notify the broadcaster of the missing packet ID (step 5
53). The broadcast station that has received the missing packet ID distributes the missing packet on a previously prepared stream (or channel) dedicated to reacquisition based on the packet ID.
The digital broadcast receiving unit 101 monitors whether or not a retransmitted missing packet has been received based on the header information added to the head of the packet (step 561). Then, the playback device 104 decodes the missing packet and outputs video and audio.
(Step 562). When the reproduction of the missing packet is completed, the process returns to step 501, and the reproducing device 104 resumes reading the packet from the next read position of the large-capacity storage medium 102.

In order to retransmit a missing packet from a broadcast station on a stream, it is necessary to distribute data only to a specific receiver. To this end, the broadcast station assigns a retransmission band for the missing packet, and assigns the band to an external communication device.
The band is transmitted to the digital broadcast receiving unit 101 from the external communication device. The digital broadcast receiving unit 101 acquires the missing packet retransmitted in the allocated band, and returns the band to the broadcasting station when the reproduction of the missing packet is completed. Alternatively, a method is also conceivable in which a unique ID is assigned to each of the receivers, and the ID is included in a packet header and the broadcast station distributes the ID. As described above, when passing through a tunnel or a weak electric field area, even if the program being received is interrupted, it is possible to obtain the missing packet from the broadcasting station using communication means such as a mobile phone and reproduce the program from the interrupted part. , Continuous viewing is possible. The case where the present invention is applied to a television broadcast program has been described above. However, it is needless to say that the present invention can be applied to a radio broadcast program, a data broadcast program, and the like.

[0025]

As described above, according to the present invention, it is possible to reliably obtain a program or information desired by a user while traveling, and if a storage medium is made portable, programs and the like recorded during traveling can be stored at home. You can also take it home and play it back. According to the present invention, the recording device records the packet output from the digital broadcast receiving unit on the storage medium regardless of the running state of the vehicle, and the reproducing device reads the packet from the storage medium when the vehicle is stopped. Since the reading of the packet from the storage medium is stopped when the vehicle is running, the video output during the running can be prohibited, and the program can be continuously watched even when the vehicle is repeatedly stopped / running. In particular, the program can be viewed continuously during long-distance driving with traffic congestion, which is effective.

According to the present invention, the recording device stops recording the packet on the storage medium when the reception of the packet is interrupted, and resumes recording the packet on the storage medium when the reception of the packet is resumed. When a loss is detected in the packet read from the storage medium, the playback device stops reading the packet from the storage medium, the external communication means requests the broadcast station to retransmit the lost packet, and the playback device returns the retransmitted lost packet. After decoding and outputting video and audio,
Since the reading of the packet from the storage medium is restarted, even if the receiving condition is deteriorated and the packet is lost, such as in a tunnel or when passing through a weak electric field area, the broadcast station replaces the missing packet with the program. Can be viewed continuously.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an in-vehicle digital broadcast receiving apparatus of the present invention.

FIG. 2 is an explanatory diagram of control of recording and reading on a large-capacity storage medium.

FIG. 3 is a flowchart of a packet recording and reproducing process depending on a running state.

FIG. 4 is a recording processing flow depending on a reception state.

FIG. 5 is a first reproduction processing flow when a packet is lost.

FIG. 6 is a second reproduction processing flow when a packet is lost.

FIG. 7 is an explanatory diagram of a case where a video elementary stream and an audio elementary stream of one broadcast program are packetized and multiplexed.

FIG. 8 is a diagram illustrating the structure of a packet.

FIG. 9 is a correspondence table of names of various tables constituting the program arrangement information SI, packet identifiers PID, and table IDs.

FIG. 10 is an explanatory diagram of a hierarchical data structure of MPEG-2 TS PSI.

FIG. 11 is a configuration diagram of a conventional digital broadcast receiver.

[Explanation of symbols]

 100 ・ ・ Digital broadcast receiver for car 200 ・ ・ Digital broadcast station 101 ・ ・ Digital broadcast receiver 102 ・ ・ Large capacity storage medium 103 ・ ・ Recording device 104 ・ ・ Playback device 105 ・ ・ Video output unit 106 ・ ・ Audio output Unit 107 Operation unit 108 Running state detection unit 109 Control circuit 110 External communication device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/765 H04N 7/173 620A 5K061 5/92 640A 7/173 620 5/91 L 640 5/92 H F-term (reference) 5C025 BA30 DA01 DA07 5C052 CC11 DD10 5C053 FA20 GA11 GB05 GB06 GB19 GB38 JA21 KA01 KA24 LA06 LA07 5C064 BA07 BB05 BB10 BC16 BC23 BC25 BD01 BD07 BD08 BD09 5K028 AA01 BB05 CC05 DD01 DD02 BB03 BB03 KK

Claims (2)

[Claims] An in-vehicle device for extracting video packets and / or audio packets of a program specified by a user from a digital broadcast signal in which video streams and / or audio streams of a plurality of programs are packetized and multiplexed, and which outputs video or audio data. In a digital broadcast receiving apparatus, a digital broadcast receiving section for outputting a packet of a program designated by a user from a received digital broadcast signal, a recording apparatus for recording the packet on a storage medium, and a reproduction for reading, decoding, and outputting the packet from the storage medium Device, a traveling state detection unit that detects a traveling state of the vehicle, the recording device records a packet output from the digital broadcast receiving unit irrespective of the traveling state of the vehicle on a storage medium, and a reproducing device includes: When stopped packets from storage media Performs read, to stop the reading of packets from the storage medium when traveling, vehicle digital broadcast receiving apparatus characterized by. An external communication means for requesting the broadcasting station to retransmit the missing packet, wherein the recording device stops recording the packet on the storage medium when the reception of the packet is interrupted, and resumes the reception of the packet. When the recording of the packet to the storage medium is resumed, the playback device stops reading the packet from the storage medium when a loss is detected in the packet read from the storage medium,
The external communication means requests the broadcasting station to retransmit the missing packet,
The in-vehicle digital broadcast receiving apparatus according to claim 1, wherein the reproducing apparatus restarts reading of the packet from the storage medium after decoding the retransmitted missing packet and outputting video and audio.