JP2004320394A - Transmitting system, receiving apparatus, and regeneration method for digital broadcasting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable comfortable watching of programs by preventing occurrence of non-continuous transmission of data due to the momentary interruption of reception when a mobile terminal receives the digital broadcasting program. <P>SOLUTION: For the transmission of the digital broadcasting data from a broadcasting station, the digital data in a buffer of the receiving terminal transmitted previously with a delay of time is reproduced even when momentary interruption of data is generated in the receiving side by duplicating the data with shift of time. In this digital broadcasting, stress of a watcher can be reduced by lowering probability for stop of image and voice output for the watchers. Moreover, it becomes possible to accurately watch digital contents by recognizing, on the data platform in the receiving terminal, a kind of digital data transmitted from a transmitting station even if any of the digital data corresponding to momentary interruption and the digital data not corresponding to momentary interruption is received only at one terminal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to transmission and reception of digital broadcasting, and more particularly, to a technique for preventing an instantaneous interruption of digital broadcasting.
[0002]
[Prior art]
Conventionally, when radio waves are interrupted during digital broadcast reception and data cannot be received, as described in Japanese Patent Application Laid-Open No. 2000-216848, additional data in a transport stream received from another device via a digital interface is used. It detects whether or not discontinuous information is included in the information, and when the discontinuous information is detected, by taking in additional information in the transport stream, a program input from the outside can be executed. 2. Description of the Related Art There is known a technique for quickly decoding video data and audio data when changed, so that decoded output is not interrupted.
[0003]
[Patent Document 1]
JP 2000-216848 A
[0004]
[Problems to be solved by the invention]
However, according to the technology disclosed in the above publication, after detecting discontinuity information, for example, when video data becomes discontinuous, the digital data is output normally last until the digital data is detected again normally. It keeps outputting digital data. Such a method would be unnatural for the viewer.
[0005]
In addition, in the above-described technologies, since it is detected that no broadcast data is coming, the generation of alternative data and the output of data that has been output normally last time are likely to cause a time lag in processing, so that real-time processing is not possible. Difficult to satisfy. This time delay is not comfortable for a viewer of digital broadcasting, and a method of complementing and outputting digital data in real time so that the viewer is not conscious of the delay is desired.
[0006]
[Means for Solving the Problems]
An object of the present invention is to transmit digital broadcast data from a broadcasting station, multiplex the digital data to be broadcast with a staggered time, and transmit the digital data with a staggered time even if a momentary interruption of data occurs on the receiving side. This is achieved by reproducing digital data that has been received.
[0007]
Further, on the data platform in the receiving terminal, the type of the broadcast data is determined by determining whether the broadcast data is multiplexed broadcast data as described above or conventional non-multiplexed broadcast data. Provided is a receiving terminal that generates reproduction data based on a type.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic configuration of a digital broadcast supplementary service of the present invention. The entire system includes a content distribution station 101 and a receiving terminal 111 such as a mobile phone type, an in-vehicle mobile reception type, or a fixed reception type. The content distribution station 101 includes a DB 102 for contents to be broadcast (contents of a program or the like), a video encoder 103 for converting video from the content DB to digital data, an audio encoder 104 for converting audio from the content DB to digital data, A multiplexing device 105 for multiplexing the data of the encoder 103 and the audio encoder 104 into a data format for digital broadcasting, and a transmitting device 106 for transmitting the digital data multiplexed by the multiplexing device 105 as broadcast radio waves (broadcast data). Is established. There is no problem with the broadcast wave as long as it is an infrastructure capable of broadcasting digital data represented by terrestrial digital broadcast waves and satellite digital broadcast waves. The receiving terminal 111 includes an antenna 118, a receiver 112 for extracting necessary data from radio waves received by the antenna, a digital demodulator 113 for demodulating data from the receiver, and digital data converted by the digital demodulator. If there is a data loss, the data complementing platform 114 performs a complementing process, the decoder 115 converts the data output from the data complementing platform into music and video data, and reproduces the output data from the decoder as music and video. A reproduction unit 116 is provided.
[0009]
Note that the content DB in the content distribution station 101 may be offline content recorded in a recording device, or real-time content from a live broadcast camera may be used. Depending on the content distribution form, when using only the audio encoder and not using video, when not using audio using only the video encoder, or when using both audio and video, it is possible to use the necessary combination when using Good choice. A general format represented by MPEG-2 and MPEG-4 is used as a data format for encoding a video. AAC is also used as a data format when encoding audio.
A general format represented by (Advanced Audio Coding) is used. The video encoder 103 and the audio encoder 104 output encoded data in an ES (Elementary Stream) format defined by ISO / IEC.
[0010]
Next, the multiplexer 105 will be described with reference to FIG. In the following description, for the sake of simplicity, a case where only audio is broadcast will be described first. In the multiplexing device 105, it is necessary to prepare at least two types of digital data output by the video encoder, for viewing and complementing, in order to cope with an instantaneous interruption.
[0011]
When the audio bit rates of the digital data for complementation and viewing are equal, the digital data encoded by one encoder is duplicated, or a plurality of digital data is generated by one encoder, and the multiplexing device is used. Then, the subsequent processing may be performed.
[0012]
If the audio bit rates of the digital data for complementation and viewing are different, or if the bit rate for viewing is higher (high quality), there are a plurality of encoders when encoding real-time broadcast content. There is a need. Alternatively, it is necessary to prepare a unit such as a bit rate reduction processing unit with one encoder.
[0013]
When the content from the content DB 102 is offline content, the content can be encoded using a single encoder when the bit rates are different, and even when the viewing bit rate is of higher quality.
[0014]
In any case, since two data are generated from one content, the digital data for viewing and complementing is the same content, and the data of two sound sources and the like are changed if the bit rates are equal. There is no place. That is, there is no change other than the bit rate. The bit rate here does not represent the transmission speed, but is the bit rate of the information source, and represents the quality of the data. Therefore, as an image having a different bit rate, for example, viewing data is a video of 256 colors, while complementing data is 16 colors. In another example, the frequency band of the viewing data is different. Is 20 to 20,000 Hz, while the frequency band of the data for complementation is 300 to 3,300 Hz.
[0015]
FIG. 2 is described below on the assumption that the bit rates of the digital data for viewing (main stream) and the digital data for complementation (sub-stream) are different. When encoding this data, two types of encoding are performed: an encoding (main stream) 2401 at a high bit rate and an encoding (sub-stream) 2402 at a low bit rate. Thereafter, since packetization is also performed, a header is added to each encoded data. It is assumed that the units of the encoded audio data are, for example, A1 to An. Note that data encoded at a high bit rate is represented by An, and data encoded at a low bit rate is represented by An '. In order to realize an instantaneous interruption compatible broadcast in which these data are not interrupted, data multiplexing is performed such that low bit rate data is transmitted first with a delay of a predetermined time delay k. This is indicated by reference numeral 2403 in FIG. The multiplexed data is superimposed on digital broadcast radio waves and broadcast to terminals. The set time k is determined in consideration of the degree of instantaneous interruption occurring at the start of service and its length. In the case of news, for example, 5 seconds, and in the case of music, for example, 10 seconds.
[0016]
An outline of a process for packetizing the encoded audio data to generate a PES will be described below. In order to recognize that digital data is missing due to a momentary interruption on the receiving side, when encoding content data, a unique index number (counter) that is continuous with the encoded and packetized content data is used. Must be assigned to The method of assigning the serial number is to extend the header and payload of the packet data and assign a counter, or as described above.
In the case of PES, the above-mentioned counter can be provided in PES_private_data at the time of encoding using PES_extension_data standardized by ISO / IEC. Which of the above methods is selected may be in accordance with the applicable broadcasting or communication terms and conditions.
[0017]
In the above, for simplicity of explanation, the case where only digital audio data is multiplexed for digital broadcasting corresponding to instantaneous interruption is described. However, when multiplexing video, video and audio, the same idea is used. It is preferable to use a method of adding counter information to PES_private_data in a PES packet in which digital data is packetized and inserted, or adding a counter by extending the header and payload of packet data.
[0018]
Next, when generating a packet, it is necessary to determine whether the broadcast data is broadcast data in preparation for a packet loss when the terminal receives broadcast data corresponding to the instantaneous interruption, that is, instantaneous interruption. Since it is necessary to determine whether or not the packet is compatible, information that can be determined is added to the packet. The first method of providing this is to put the information in a stream_id 302 in the format 301 of the PES packet in the ISO / IEC13818-1 standard shown in FIG. The stream_id is 8 bits, the upper 3 bits of which are fields indicating the type of data such as audio and video, and the lower 5 bits can be arbitrarily determined. It may be specified. For example, when the stream_id is 11011111, an audio stream corresponding to an instantaneous interruption, and when the stream_id is 11000000, an audio stream not corresponding to an instantaneous interruption, this information can be unified on the terminal side and the content distribution station that encodes the content. Consistency can be achieved.
[0019]
Up to this point, a method has been described in which information for responding to a momentary interruption to PES data is added to a packet. On the other hand, in addition to the PES level, there is a method in which information for determining whether digital data corresponds to an instantaneous interruption at the TS level is added to a data packet. As a second method of adding the data, the content is encoded as described above in the stream_type 403 of (401) in the standard for the PMT (Program Map Table) of the TS packet shown in ISO / IEC13818-1 shown in FIG. If a unified value is determined between the content distribution station and the receiving terminal, consistency can be obtained.
[0020]
As a third method for adding information for determining whether or not digital data corresponds to an instantaneous interruption to a data packet, the third method exists in 402 and 404 in the PMT described above.
The determination can be made by writing a code corresponding to the instantaneous interruption to descriptor (). This can also be made consistent by arranging unified values on the content encoding side and the receiving terminal side.
[0021]
As described above, after the packet counter and the identifier for determining whether the data is broadcast data corresponding to instantaneous interruption are added to the data packet, the multiplexing device 105 multiplexes the audio / video viewing stream and the complementing stream. The output digital data is output to the transmitting device 106. When data is multiplexed by the multiplexer 105, the data may be multiplexed at either the PES level or the TS level. Which format should be used for multiplexing may be in accordance with the standard for actually performing broadcasting and communication. The transmission device 106 performs encoding and modulation for superimposing digital data output from the multiplexing device on the broadcast radio wave, and then transmits the broadcast data to the service target area as a radio wave.
[0022]
Explaining the above again, two content data are generated from one content (audio, video, etc.). Next, each content data is packetized, and these are multiplexed at staggered times to create broadcast data. The created broadcast data is transmitted from the transmission device. The content data in the broadcast data to be transmitted earlier in time is used for complementation on the receiving side.
[0023]
As described above, the number and functions of the required encoders differ depending on whether the bit rates of the two content data are equal or different. At the time of packetization, a header having a counter and an index number is added to the packet. Further, an identifier for determining whether or not the broadcast data corresponds to the momentary interruption is added.
[0024]
When the bit rate of the content data for viewing is higher than the bit rate of the content data for complementation, there is an advantage that the data amount can be reduced as a whole, and when the bit rates are equal to each other, the encoder has an advantage. There is an advantage that only one is required.
[0025]
Such multiplexing or the like to generate broadcast data is performed in the past even when a momentary interruption of broadcast data occurs on the receiving side (time before the instantaneous interruption on the receiving side, ~ This is because the viewing data is complemented by using the complementing content data in the broadcast data received at a time earlier than the broadcast data, so that the instantaneous interruption does not occur in the entire reproduction data.
[0026]
Next, the receiving terminal 111 will be described. The receiving terminal 111 includes an antenna 118 for receiving a radio wave, a receiver 112 for receiving a radio wave received by the antenna, a digital demodulator 113 for demodulating a radio wave from the receiver to extract original digital data, and a digital demodulator. From the digital data into data packets, and further classify the data into data for viewing and complementing, and in the case of missing data, select appropriate data stored in the buffer after receiving data A platform 114, a decoder 115 for decoding digital data output from the data complementing platform into music and video, and a reproducing unit 116 for reproducing data from the decoder as audio and video are provided.
[0027]
Since the antenna 118, the receiver 112, and the digital demodulator 113 are generally well known, the data complement platform will be described below with reference to FIG. The data complementing platform includes a packet receiver 2501, a data separator 2502, a main stream buffer 2503, a sub stream buffer 2504, and a data selector 2505. The packet receiver 2501 is a device that extracts a data packet from digital data passed from a digital demodulator. The function of the data separator 2502 is to extract the audio and video data from the packetized digital data from the packet receiver after determining whether the received digital data is data corresponding to the instantaneous interruption, and And the sub-stream data are stored in the main stream buffer 2503 and the sub-stream buffer 2504 at the subsequent stage.
[0028]
Here, if the data separator 2502 determines that the received digital data is not the data corresponding to the instantaneous interruption, the substream buffer becomes unavailable until the broadcast data corresponding to the instantaneous interruption is input to the receiver. The data selector, which will be described later, also has a function of simply passing data from the main stream buffer 2503 to the player (reproducing unit) 116. As described above, the determination as to whether or not it corresponds to the instantaneous interruption is made to stream_id when the identification data is added to the PES in the digital data packet, and to stream_type or descriptor () when the identification data is added to the TS. This is performed by determining the described data.
[0029]
The data selector 2505 selects which of the buffer for the main stream data and the data for the substream separated by the data separator is to be passed to the decoder. The procedure for selecting either the data in the main stream buffer or the data in the substream buffer in the data selector 2505 will be described with reference to FIG.
[0030]
FIG. 6 is a flowchart showing an outline of the processing in the data selector. First, the number of the first data in the main stream buffer and the sub stream buffer is stored by the data selector in step 601. Next, it is determined in step 602 whether or not the receiving terminal has just been started. If it has just been started, the process 603 is executed. processing
603 will be described with reference to FIG. If it is determined in step 602 that the data has just been started, it is determined in step 701 whether or not the number (request number) of data to be passed to the next decoder is 0. If it is 0, the process 702 designates the data in the main stream buffer as a candidate for acquisition. If the request number is not 0, the process exits the process 603 and returns to the process 601 again.
[0031]
If the data selector 2505 determines in step 602 that it is not immediately after activation, it determines in step 604 whether the main stream buffer and the sub stream buffer are empty. If both are empty, the process proceeds to step 605. After proceeding to the process 605, it is determined in a process 711 (see FIG. 7) whether or not data is contained in the main buffer. After confirming that the buffer is empty in the process 604, and further confirming the presence or absence of the contents of the main stream buffer in the process 711, new digital data enters the buffer during the transition of this process. This is because there is a possibility. If it is determined in step 711 that there is no data in the main stream buffer, then in step 712 it is determined whether new data is in the substream buffer. When new data comes into the substream buffer in the process 712, the data in the main stream buffer (higher quality or the same quality as the data in the substream buffer) is preferentially reproduced. The processing is stopped for a preset time in processing 713. This time is determined according to, for example, the CPU speed of the terminal to be used and the data transfer speed. If new data comes into the main stream buffer in the process 711, the process exits the process 605 and returns to the process 601. Also, when no data is contained in the sub-stream buffer in the process 712, the process exits from the process 605 and returns to the process 601.
[0032]
If it is determined in step 604 that the data in the main / substream buffer is empty, the process proceeds to step 606, where the request data stored in the data selector is either the main stream buffer or the substream buffer. Is determined. If the data exists in any of the stream buffers, the process proceeds to step 607.
[0033]
Details of the process 607 will be described with reference to FIG. Process first in process 607
At 801, it is determined whether or not the request data is in the main stream buffer. If this determination is correct, the data selector 2505 passes the data in the main stream buffer to the decoder 115. After that, the process exits from the process 607 and sets the next number of the request data to the value of the request data in the process 609. Thereafter, the process returns to step 601 to search for the next data.
[0034]
If the requested data is not in the main stream buffer in process 801, process
At 803, it is determined whether the requested data is in the substream buffer. If the data exists in the substream buffer, the data selector 2505 passes the data in the substream buffer to the decoder 115 in step 804. After that, the processing moves to the processing 609, changes to request the data of the next number of the acquired data, and returns to the processing 601.
[0035]
If the data requested in step 803 does not exist in the substream buffer, a flag indicating a condition error is returned to the data selector in step 805, and the process moves to step 609. The next number of the acquired data is set and the step 601 is executed. Return to If it is determined in step 606 that the requested data cannot be found in either the main or sub-stream buffer, step 608 is executed.
[0036]
Details of the process 608 will be described with reference to FIGS. First, when it is determined in step 901 that there is no data in the main stream buffer, it is determined in step 902 whether the head number of the data in the sub-stream buffer is smaller than the required data. If the determination is made, the data head number in the substream buffer is set to the request number in step 903. After performing the process, the process returns to the process 601 to continue the subsequent processes. If the determination in the process 902 does not hold, the next data in the sub-stream buffer is searched in the process 904. Thereafter, the process exits from the process 608 and returns to the process 601.
[0037]
If it is determined in step 901 that there is data in the main stream buffer, it is determined in step 905 whether the data in the main stream buffer is earlier than the search request data. If this determination is correct, it is determined in step 906 whether or not the data serial number has been inverted. If the data serial number is inverted in the judgment of the process 906, the process returns to the process 601 after setting the number of the first packet of the main stream buffer to the search request number in the process 907. If the inversion of the data serial number is not detected in the process 906, the next packet number in the main stream buffer is set as the search request number, and then the process exits the process 608 and returns to the process 601.
[0038]
If the above determination is not correct in the process 905, it is determined in a process 909 whether the number of the head data of the substream buffer is data before the search request data. If this determination is correct, the process proceeds to step 910 after setting the next packet number in the sub-stream buffer as the search request number. Otherwise, the process moves to process 911 without performing any process. If the start data number of the main stream buffer is smaller than the start data number of the sub-stream buffer in step 911, the start packet number of the main stream buffer is set as the search request number in step 912. If the process 911 does not hold, in a process 913, the number of the first packet of the sub-stream buffer is set as the search request number. After the processes 912 and 913 are completed, the process exits from the process 608 and returns to the process 601 to search again for the corresponding packet.
[0039]
The above will be described again as follows.
[0040]
When the broadcast data that does not support the instantaneous interruption is received, the substream buffer is not used, the data is stored in the main stream buffer, and the data selector only passes the data from the main stream buffer 2503 to the player (reproducing unit) 116. It becomes. Therefore, even if broadcast data that does not support instantaneous interruption is received, there is no problem in reproducing audio and video data.
[0041]
When the instantaneous interruption corresponding broadcast data is received, when an instantaneous interruption occurs and the viewing data is lost, the stored supplementary data is brought in and complemented, and the reproduction data is used using the supplemented viewing data. Generate Or, similarly, the reproduction data is usually generated using the viewing data, and when there is a missing data, the reproduction data is generated using the complementing data. At this time, if the supplementary data is stored in the storage means for a long time, it becomes possible to reproduce the audio and video so that the broadcast is not interrupted even when passing through the tunnel. Also, whether or not a momentary interruption has occurred can be determined by using whether or not a packet of digital data for viewing (main stream) in the broadcast data is missing. A packet with an index number corresponding to the missing packet in the viewing data is fetched from the complementing data, the viewing data is complemented, and reproduction data is generated from the supplemented viewing data. Or, similarly, in a normal state where there is no loss, a data packet of the viewing data is selected, and when a data packet of the viewing data is lost, the data packet corresponding to the missing packet is handled. The packet with the index number is selected from the complement data. The reproduction data is generated based on the selected packet.
[0042]
As described above, the digital content can be normally viewed regardless of whether the single terminal receives digital data corresponding to instantaneous interruption or digital data not corresponding to instantaneous interruption.
[0043]
In the above embodiment, it is assumed that the receiving terminal has a plurality of buffers (2503 and 2504 in FIG. 5) for storing data for instantaneous interruption.
[0044]
However, even a receiving terminal having a simple configuration as shown in FIG. 11, that is, a receiving terminal not having a plurality of buffers, needs to support the digital data (broadcast data) corresponding to the instantaneous interruption. In such a configuration, that is, in a configuration in which the receiving terminal does not support the instantaneous interruption even though the broadcast data is instantaneous interruption compatible, on the other hand, when the terminal receives non-interruptible broadcast data in the discontinuous state, At the same time, a break such as voice occurs. On the other hand, if broadcast data for instantaneous interruption is received, the data is multiplexed and if the data is played back sequentially, the sound will be heard alternately and repeatedly in a short cycle. Harassing.
[0045]
Therefore, when a stereo broadcast is received even on a radio that can only play monaural, it can be reproduced in monaural as well-even if the receiving terminal is not compatible with instantaneous interruption, it is unavoidable that sound etc. will be interrupted- -When receiving broadcast data (multiplexed broadcast data) corresponding to momentary interruption, it is necessary that the receiving terminal be capable of properly reproducing sound and the like.
[0046]
An embodiment of the receiving terminal as described above will be described with reference to FIG. FIG. 11 includes a packet receiver 2501, a decoder 115, and a player (playback unit) 116 as in FIG. 5, and these have the same functions as those described in the description of FIG. 11 differs from FIG. 5 in that a data filter 1101 is provided instead of the data separator 2502, the main stream buffer 2503, the substream buffer 2504, and the data selector 2505.
[0047]
The function of the data filter 1101 will be described with reference to FIGS. Reference numeral 1201 in FIG. 12 is an example of digital data having a format called TS in digital data. In this example, the audio data has already been encoded in the ES format, and the two types of audio data in the PES state are a series of PES packets whose PID indicated by 1202 is 0x0032. This PES packet 1202 is composed of digital data 1301 and 1304 shown in FIG. Since the digital data 1301 and 1304 have the same format, the digital data 1301 will be described as a representative. Reference numeral 1302 denotes a stream ID, which is used to determine the main stream and the substream. For example, even-numbered Stream IDs are main streams, and odd-numbered Stream IDs are sub-streams.
[0048]
Such a rule needs to be matched between the transmitting side and the receiving side. In the example of digital data shown in 1301, PES Priority can be used as an index for determining such a main stream and a sub stream.
[0049]
Based on such a Stream ID and PES Priority, only matching data is filtered and passed to the player (reproducing unit) 116, and other unmatched data is discarded. Preventing the phenomenon of repeated reproduction makes it possible to reproduce normal sound and the like as usual. In the data filter, when the bit rates of the multiplexed content data are the same, the data having the overlapping Stream ID is deleted. When the bit rates of the multiplexed content data are different from each other, the low bit rate of the data having the overlapping Stream ID is deleted. Delete data. Delete the one received earlier and extract the one received later. When the bit rates are the same, the one received first may be extracted and the one received later may be deleted.
[0050]
As a configuration, for example, in preparation for an instantaneous interruption of broadcast data at the time of reception, broadcast data generated by multiplexing two pieces of the same content data at staggered times is received, and a stream ID or PES is generated by a data filter. By checking the Priority, the content data in the received broadcast data, which is to be received at a later time, is extracted, and the extracted content data is passed to the decoder. A method of generating reproduction data based on the reproduction data and reproducing the reproduction data is employed.
[0051]
【The invention's effect】
It is possible to reproduce digital broadcasts without instantaneous interruption. Therefore, a broadcast with less stress for the viewer can be realized.
[0052]
In addition, the digital content can be normally viewed regardless of whether one terminal receives digital data compatible with instantaneous interruption or digital data not compatible with instantaneous interruption.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a digital broadcast complement system of the present invention.
FIG. 2 is a conceptual diagram of data multiplexing.
FIG. 3 shows a part in a PES packet describing an identifier of instantaneous interruption corresponding data.
FIG. 4 shows a portion in a TS packet describing an identifier of instantaneous interruption corresponding data.
FIG. 5 is a configuration diagram of a receiving terminal data receiving platform.
FIG. 6 is a schematic processing diagram of a data selector.
FIG. 7 is a schematic processing diagram of a data selector.
FIG. 8 is a processing schematic diagram of a data selector.
FIG. 9 is a schematic processing diagram of a data selector.
FIG. 10 is a schematic processing diagram of a data selector.
FIG. 11 is a configuration diagram of a receiving terminal data receiving platform.
FIG. 12 is a diagram (1) for explaining the function of the data filter 1101;
FIG. 13 is a diagram (2) illustrating the function of the data filter 1101;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 101 ... Content distribution station, 102 ... Content DB, 103 ... Video encoder, 104 ... Audio encoder, 105 ... Multiplexer, 106 ... Sending device, 111 ... Receiving terminal, 112 ... Receiver, 113 ... Digital demodulator, 114 ... Data complementing platform, 115 Decoder, 116 Reproducing unit, 301 Extract of PES packet standard in ISO / IEC, 401 PAT standard in TS in ISO / IEC, 2400 Encoded data, 2401 Main stream data, 2402 Substream data, 2403: Data after multiplexing, 2501: Packet receiver, 2502: Data separator, 2503: Main stream buffer, 2504: Substream buffer, 2505: Data selector.

Claims (13)

In a digital broadcast transmission system that packetizes two pieces of content data having the same content into packets and broadcasts multiplexed broadcast data,
A data encoder that adds a header having an index number in each of the packets when the packetization is performed;
When the broadcast data is received, even if a packet in one content data is lost due to a momentary interruption of the broadcast data, the other one of the broadcast data received at a time earlier than the moment of the instantaneous interruption The two pieces of content data are multiplexed with a time interval shifted from each other so that the missing packet can be complemented using a packet having an index number corresponding to the index number of the missing packet from the content data. And a multiplexing device for generating the broadcast data,
A digital broadcast transmission system having: In claim 1,
A digital broadcast transmission system, wherein the bit rate of the one content data is higher than the bit rate of the other content data composed of packets used for complementation. In claim 1,
A digital broadcast transmission system, wherein a bit rate of the other content data composed of packets used for complementation is equal to a bit rate of the one content data. In claim 1,
The data encoder has a function of assigning, to a Stream_id identifier in a PES packet defined by the ISO / IEC standard, that the broadcast data is broadcast data in preparation for a packet loss. Digital broadcast transmission system. In claim 1,
The data encoder has a function of giving, in PES_private_data in a PES packet defined by the ISO / IEC standard, that the broadcast data is broadcast data in preparation for a packet loss. Digital broadcast transmission system. In claim 1,
The data encoder has a function of assigning, to a Stream_type identifier in a TS packet defined by the ISO / IEC standard, that the broadcast data is broadcast data in preparation for a packet loss. Digital broadcast transmission system. In claim 1,
The data encoder has a function of giving, to a descriptor identifier in a TS packet defined by the ISO / IEC standard, that the broadcast data is broadcast data in preparation for a packet loss. Digital broadcast transmission system. In preparation for a packet loss, broadcast data multiplexed at a time lag with two identical content data consisting of a packet to which a header having an index number is added, and a broadcast data that is not multiplexed as described above. An antenna for receiving both of the broadcast data,
Means for determining whether the received broadcast data is broadcast data multiplexed with two identical content data in preparation for packet loss,
When the broadcast data is determined to be broadcast data multiplexed by two identical content data in preparation for a packet loss, the broadcast data is separated into the two original content data. Separating means for generating first content data and second content data,
Storage means for storing the second content data,
Determining means for determining a loss of a packet of the first content data;
When it is determined by the determination unit that the packet of the first content data is not missing, the packet of the first content data is selected, and the packet of the first content data is determined to be missing. If determined, selecting means for selecting a packet of an index number corresponding to the index number of the missing packet from the second content data stored in the storage means,
Decoding means for decoding data for reproduction from each packet selected by the selection means;
A digital broadcast receiving apparatus comprising: a reproducing unit that reproduces the reproduction data decoded by the decoding unit. In claim 8,
When the received broadcast data is not the multiplexed broadcast data in preparation for the packet loss, if it is determined by the determination unit,
The receiving device for digital broadcasting, wherein the selecting means selects a packet of content data constituting the broadcasting data. In claim 8,
A digital broadcast receiving apparatus comprising: determining whether a packet in the first content data has been dropped due to an instantaneous interruption of the broadcast data using radio wave intensity. In claim 8,
A digital broadcast receiving apparatus comprising: determining whether or not a packet in the first content data has been dropped due to an instantaneous interruption of the broadcast data by using a continuity_counter of a transport stream packet. . In preparation for an instantaneous interruption of broadcast data at the time of reception, receive broadcast data generated by multiplexing two identical content data with a time delay,
Determine whether or not the received broadcast data is multiplexed broadcast data as described above,
If determined to be true, the broadcast data is separated into the original two content data,
If it is determined that a part of one of the content data used for reproduction is missing, the other content data is used to complement the one content data,
A digital broadcast playback method for generating playback data based on the one content data supplemented as necessary and playing back the playback data. In claim 12,
A digital broadcast reproduction method for generating reproduction data based on the broadcast data when it is determined that the broadcast data is non-existent, and reproducing the reproduction data.

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