JP2007074671A - Pid value detection circuit, stream data receiver and pid value detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire, at high speed, a PID (packet identifier) value of each of video/audio data out of received TS (transport stream) packets without utilizing information of PAT or PMT. <P>SOLUTION: In a PES-PID detection section 102, a header and a payload of a received TS packet are analyzed through predetermined procedures. First of all, whether it is possible to include a PES packet is determined by a payload start unit indicator check section 130, the existence of the PES packet is then confirmed from a value of a payload header by a payload header check section, it is confirmed by a stream identifier check section 132 that video data or audio data are included and then, a PID value extraction section 133 extracts a PID value included in the header of the TS packet as a PID value of a TS packet including video data or audio data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention receives multimedia data that is compressed and multiplexed by the Moving Picture Experts Group 2 (MPEG2) method and transmitted as a TS (transport stream) by a receiver, and refers to a video and a PID (packet identifier). With regard to technology that separates audio at high speed and technology that records decoded video and audio data, it receives digital terrestrial broadcasting (1-segment broadcasting) from a mobile terminal with a digital terrestrial tuner and separates video and audio at high speed. And a technique for recording decoded video and audio data.

  In the MPEG2 (Moving Picture Experts Group 2) standard, which is a moving picture transmission standard, image data and audio data are composed of one frame for one screen for images and one frame for a certain sample for audio. Each frame is compressed and encoded, and one frame or a plurality of frames are collected to form a packet called a PES (packetized elementary stream). This PES packet is inserted into the payload portion of a TS (transport stream) packet.

  Similarly, program guide data and data including an encryption key are referred to as program specific information (PSI Program Specific Information), and are divided into sections and inserted into the payload of the TS packet.

  The PSI includes a PAT (program association table), a PMT (program map table), and the like. For example, the PSI information is transmitted once within 0.7 seconds. The PAT or PMT records which packet has what PID (packet identifier) value.

  One TS packet has a fixed length of 188 bytes, and is composed of a packet header having a fixed length of 4 bytes, followed by a data portion of 184 bytes. The data portion is composed of a variable-length adaptation field (which may not be present) and a payload.

  Therefore, the TS packet has a TS header (4 bytes) + adaptation field (may be missing) + PES packet configuration, or a TS header (4 bytes) + adaptation field (may be missing) + section configuration. Can be broadly divided.

  In addition, PES, which is continuous information from one information source, is divided into a plurality of packets, multiplexed with PES packets from other information sources, and stream-transmitted. A PID (Packet Identification) is added to the header of the first 4 bytes of each TS packet so that it can be constructed.

  That is, the 4-byte header of the TS packet includes a PID (packet identifier) indicating what kind of packet it is.

  In order to receive the TS (Transport Stream) and reproduce the multimedia information, first, the video / audio is discriminated by referring to the PID of each TS packet, and both are separated, and then the TS packet is decoded ( The video / audio information is reproduced by performing demultiplex processing.

  Here, in order to discriminate video / audio from the received TS and to separate them, the playback apparatus on the receiving side determines what PID value each packet carrying video data / audio data originally has. It is necessary to know in advance.

  Here, as described above, which packet has which PID value is recorded in a PAT (program association table) or PMT (program map table), and unless this PAT or PMT is restored. , PID information cannot be obtained.

  Therefore, in order to reproduce multimedia data, in principle, first, PAT and PMT are selected and reproduced using the fact that PAT and PMT have an invariable PID value, Information on the PID value of the packet having audio data is obtained, and then the video / audio data is separated with reference to the PID value.

  However, if the PAT (Program Association Table) or PMT (Program Map Table) must be played before the video / audio separation, there is an adverse effect that the cueing of video and audio is delayed.

  In view of this, conventionally, there has been proposed a technique for quickly separating video / audio data without performing PAT or PMT playback and analysis (for example, Patent Document 1 and Patent Document 2). reference).

  In Patent Document 1, the PID values of video packets and audio packets are fixed (invariable) so that video / audio data can be separated immediately without performing PAT or PMT playback and analysis. ing.

  In Patent Document 2, prior to TS stream transmission, PAT values of video packets and audio packets are notified in advance from the transmission side to the reception side via a different route, so that PAT and PMT are not reproduced and analyzed. However, the video / audio data can be separated immediately.

  In Japan, terrestrial digital broadcasting started on December 1, 2003, but by the end of 2005, terrestrial digital broadcasting (1 segment broadcasting) for mobile terminals such as mobile phones (mobile) started. Development of a portable terminal with a built-in digital tuner capable of viewing this 1-segment broadcasting is currently underway.

  FIG. 10 is a diagram for explaining a hierarchical transmission method in terrestrial digital broadcasting in Japan.

  In Japan's terrestrial digital broadcasting, the ISDB-T system is adopted. That is, the 6 MHz band (corresponding to one channel of conventional analog broadcasting) broadcast from the broadcasting station 290 of FIG. 10 is characterized by being divided into 13 subbands and operated. Here, each subband is called a segment.

  For example, high-quality HD (high definition) transmission for the HDTV 304 installed in the house 300 can be implemented using all 12 segments. In addition, it is possible to provide three programs of SD (standard definition) broadcasting for the SD television 302 using four segments, and flexible program organization is possible.

  One segment out of 13 segments is reserved for mobile broadcasting, and using this one segment provides simple video broadcasting for mobile phones and PDAs. Broadcast).

  In order to receive a 1-segment broadcast on a mobile terminal, a broadcast stream (TS) compressed and multiplexed in MPEG2 is received, various media data is separated from the broadcast stream (TS), and media data is reproduced and presented. It is necessary to have a function for recording media data as necessary.

JP 2000-228654 A JP-A-8-186805

  In the technique described in Patent Document 1, since the PID value of each video / audio packet is fixed, it cannot be denied that the degree of freedom and flexibility of transmission are lacking.

  In the technique of Patent Document 2, the PID value of each video / audio data is notified in advance by another route prior to TS transmission. However, in order to realize this method, the PID value must be notified. A separate route is necessary for this purpose, which increases the burden of infrastructure development, and this method cannot be denied that there are restrictions in terms of freedom of transmission and flexibility.

  On the other hand, for example, since users of mobile terminals are accustomed to enjoying moving images using a communication function, if quick cueing is not possible even when receiving a 1-segment broadcast, the user is frustrated. Disadvantages arise.

  In addition, since miniaturization, weight reduction, and low power consumption are strictly required for mobile terminals, it is burdensome to install an advanced tuner for receiving broadcast streams for receiving 1-segment broadcasting. . In particular, when each of the reproduced video / audio data can be recorded, not only the data itself, but also PAT (program association table) and PMT (program map table) information and PID (packet identifier) value information are included. In this respect, the amount of information to be saved increases, and in response to this, a large-capacity memory must be prepared, which is reduced in size, weight, and power consumption. Disadvantageous.

  Note that the above-described prior art is not mentioned at all for a portable terminal having a reception function for one-segment broadcasting.

  The present invention has been made based on such considerations, and receives multimedia data compressed and multiplexed by the MPEG2 system and transmitted as a TS (transport stream) by a receiver. A technique for acquiring information on PID (packet identifier) values of unfixed video / audio data and separating the video and audio at low speed with reference to the acquired PID values, and decoding Providing a technology for recording recorded video and audio data while reducing the burden on the memory, and receiving small terrestrial digital broadcasting (1-segment broadcasting), high-speed playback, and recording functions. It aims at realizing a data receiver and a portable terminal.

  A PID detection circuit according to the present invention is a PID value detection circuit that analyzes information included in a transport stream packet (TS packet) and detects a PID value of a TS packet including video data or audio data. A payload unit start indicator determination unit that determines the possibility that the start point of the payload is the start point of a packetized elementary stream packet (PES packet) with reference to the value of the payload unit start indicator in the packet header; When it is determined that there is a possibility that the start point is the start point of a packetized elementary stream packet (PES packet), the packet start code is referenced by referring to the packet start code prefix in the header of the payload in the TS packet. A payload header determination unit for determining whether or not a PES packet is included in the mode, and when it is determined that a PES packet is included in the payload, the stream identifier of the payload header in the TS packet is a video A stream identifier determination unit that determines whether or not data or audio data is indicated; and when it is determined that the stream identifier indicates video data or audio data, the PID value of the TS packet And a PID value extracting unit that extracts as a PID value of a TS packet including video data or audio data.

  Rather than relying on PAT (Program Association Table) or PMT (Program Map Table) information, the received TS packet is analyzed in a brute force manner and according to a predetermined procedure, thereby including video data or audio data. The TS packet is selected, and the PID (packet identifier) value described in the header of the selected TS packet is set as a desired PID value (that is, the PID value of the TS packet including video data or audio data). To extract. That is, as a result of analysis, when the data included in the TS packet is data of audio (1) and the PID value of the TS packet is “0010”, the PID of the TS packet including the data of audio (1) Value = “0010” can be detected. If the PID value can be detected in this way, in the next process, the PID value of the received TS packet is referred to, and all data having the value “0010” are extracted, so that the audio (1) data is obtained. Only TS packets including can be extracted separately from other TS packets. This also means that a TS packet including video data and a packet including audio data can be selectively separated. The TS packet is analyzed by determining the possibility of the presence of a PES packet by checking a payload unit start indicator, checking the presence of a PES packet by checking a packet start code prefix in the payload header, and checking the stream identifier in the payload header. This is performed by sequentially performing a series of procedures of confirming the presence of any audio data and extracting the PID value of the TS packet. As described above, a TS packet analysis requires a plurality of steps including checking of both the header and the payload. However, in the current mobile phone terminal or the like where a high-speed clock is used, such a process is easy. Can be implemented. For example, the processing of latching one TS packet, header analysis, and payload analysis can be performed in a pipeline manner in synchronization with a high-speed clock. Further, in the technology of the present invention, there is no need to fix the PID value of a packet including video data as in the prior art, so there is no problem in flexibility and expandability. Since there is no need to convey the message to the receiving side, no extra procedure is required.

  In one aspect of the PID value detection circuit of the present invention, when the value is “1”, it is determined that there is a possibility that the start point of the payload is the start point of the PES packet, and the payload header determination When the packet start code prefix starts with “000001”, the unit determines that the PES packet is included in the payload, and the stream identifier determination unit uses a value assigned to the video data as the stream identifier. In some cases, it is determined to be video data, and in the case of a value assigned to audio data, it is determined to be audio data.

  Focusing on the structure of TS packets conforming to the MPEG2 standard, a composite analysis of TS packets consisting of a plurality of steps including checking of both headers and payloads is performed, whereby desired multimedia data (video data) is obtained. / Audio data) is efficiently detected.

  In one aspect of the PID value detection circuit of the present invention, the transport stream packet conforms to the MPEG2 standard.

By detecting the PID value of the desired multimedia data from the MPEG2 standard TS packet, the PID value of the TS packet including video data or audio data can be detected quickly and efficiently without relying on PAT or PMT information. This contributes to the realization of a receiver having a terrestrial digital broadcast tuner capable of high-speed cueing.

  Further, the stream data receiver of the present invention performs information analysis on each of a reception unit that receives a transport stream (TS) and a plurality of TS packets that constitute the TS received by the reception unit, and performs PID A PID value detection circuit of the present invention for detecting a value, and a PID value for the video data or audio data extracted by the PID value detection circuit from the plurality of TS packets received by the receiving unit. A PES packet separating unit that separates a PES packet including video data from a PES packet including audio data, and decoding video data and audio data from each of the separated video and audio PES packets. A decoding unit.

  A stream data receiver in which the PID value detection circuit of the present invention is arranged in the preceding stage of the PES packet separation unit and enables separation of PES packets using the detected PID value (that is, separation of desired multimedia data). It is. In a conventional receiver, by utilizing the fact that a packet including a PAT (program association table) or PMT (program map table) has a fixed PID value, first, a TS packet including the PAT or PMT is reproduced and a desired multi-channel is reproduced. Since it is necessary to know what PID value the packet containing media data has, the TS packet containing video data / audio data cannot be selected from the received TS. Playback is delayed, and TS packets received before PAT and PMT are played back are discarded. On the other hand, the stream data receiver of the present invention does not cause such a problem, and can reproducibly reproduce a very high speed video signal / audio signal.

  The stream data receiver according to one aspect of the present invention further includes a recording / reproduction control unit that controls recording of information of each separated video and audio PES packet and reproduction of the recorded information. The recording / reproduction control unit does not record PAT (program association table) and PMT (program map table) information and information on the PID value detected by the PID detection circuit when recording the information of the PES packet.

  In recent years, stream data receivers have many types (recordable / reproducible types) having a recording function as well as a multimedia signal reproduction function. A conventional stream data receiver needs to record the PID (program association table) or PMT (program map table) or the PID value of the detected TS packet separately when the received TS packet is once recorded. Therefore, the size of the recording file is increased, and it is necessary to secure a recording area (various recording media such as a memory, a hard disk, and an SD card) for storing the large recording file. On the other hand, the stream data receiver of the present invention has a function of analyzing the TS packet itself to be recorded and obtaining the PID value of the TS packet including video data / audio data. There is no need to record PMT or information of the acquired PID value separately. Therefore, it is possible to reduce the size of the recording file, which is advantageous in terms of cost reduction, size reduction, and power consumption reduction of the receiver.

  In another aspect of the stream data receiver of the present invention, the stream data receiver is a portable terminal including a terrestrial digital broadcast tuner unit as the receiving unit.

  For example, since users of mobile terminals are accustomed to enjoying moving images using the communication function, it is necessary to prompt the user for quick cueing even when receiving 1-segment broadcasting (terrestrial digital broadcasting for mobile terminals). Disadvantages such as creating an irritating feeling occur. In addition, since mobile terminals are required to be small, light, and consume low power, it is inherently a burden to install an advanced tuner broadcast stream receiving application for receiving 1-segment broadcasting. Is big. However, according to the present invention, high-speed video / audio signals can be reproduced, the waiting time until reproduction can be reduced, and the size of the recording file at the time of recording can be reduced. Therefore, according to the present invention, it is possible to promote the realization of a small-sized, light-weight, low power consumption and high-performance portable terminal having a terrestrial digital broadcast receiving function.

  In addition, the PID value detection method of the present invention analyzes video included in a transport stream packet (TS packet), thereby making it possible to refer to video without referring to PAT (program association table) and PMT (program map table) information. A PID value detection method for detecting a PID value of a TS packet including data or audio data, wherein a payload start point is a packetized elementary stream packet with reference to a value of a payload unit start indicator in a header of the TS packet A first step of determining the possibility of being the start point of a (PES packet), and when it is determined that the payload start point may be the start point of a packetized elementary stream packet (PES packet) , That T By referring to the packet start code prefix in the header of the payload in the packet, it is determined that the payload includes a PES packet in the second step of determining whether the PES packet is included in the payload. A third step of determining whether or not the stream identifier in the header of the payload in the TS packet indicates video data or audio data, and that the stream identifier is video data or audio data. A fourth step of extracting the PID value of the TS packet as the PID value of the TS packet including video data or audio data when it is determined that the TS packet is indicated.

  Possibility of existence of PES packet by checking payload unit start indicator, confirmation of existence of PES packet by checking packet start code prefix of payload header, video / audio data by checking stream identifier of payload header Perform a complex analysis step that includes checking both the header and payload, such as confirming the existence of the TS packet and extracting the PID value of the TS packet, and the PID value of the TS packet including the desired multimedia data is It is something to detect.

  Also, the PES packet separation method of the present invention is a method of separating a TS packet having a PID value for the video data or audio data detected by the PID value detection method of the present invention from a plurality of received TS packets. In this way, a PES packet including video data and a PES packet including audio data are separated.

  By using the PID value detection method of the present invention, a PES packet including video data and a PES packet including audio data are separated at high speed without relying on PAT or PMT information.

  The PID value detection circuit of the present invention performs complex analysis including checking of both the header and payload of the TS packet, so that it does not rely on PAT (Program Association Table) or PMT (Program Map Table) information. The PID value of a TS packet including video data or audio data can be detected at high speed and efficiently.

  Further, in the PID value detection technique of the present invention, it is not necessary to fix the PID value of a packet including video data as in the conventional technique, so that there is no problem in flexibility and expandability. Since it is not necessary to convey the PID value to the receiving side by the route, no extra procedure is generated.

  In addition, the PID value detection circuit of the present invention is arranged in the preceding stage of the PES packet separation unit, and the PES packet separation using the detected PID value is performed, so that the video signal / audio signal can be separated very quickly. And reproduction can be realized without difficulty.

  Further, according to the present invention, there is no problem of packet discard until the PAT or PMT is reproduced as in the prior art.

  Further, the stream data receiver of the present invention has a function of analyzing the TS packet itself to be recorded and obtaining the PID value of the TS packet including video data / audio data. There is no need to separately record information on the PMT, information on the acquired PID value, or the like. Therefore, it is possible to reduce the size of the recording file, which is advantageous in terms of cost reduction, size reduction, and power consumption reduction of the receiver.

  Further, according to the portable terminal of the present invention, high-speed video / audio signals can be reproduced, the waiting time until reproduction can be reduced, and the size of the recording file at the time of recording can be reduced. Become. Therefore, according to the present invention, it is possible to promote the realization of a small-sized, light-weight, low power consumption and high-performance portable terminal having a terrestrial digital broadcast receiving function.

  Further, according to the PID value detection method of the present invention, it is possible to determine the possibility of the presence of a PES packet by checking the payload unit start indicator, to confirm the presence of the PES packet by checking the packet start code prefix of the payload header, Perform a complex analysis step that includes checking both the header and payload, confirming the presence of either video / audio data by checking the stream identifier, extracting the PID value of the TS packet, and It becomes possible to detect the PID value of the TS packet including the multimedia data at high speed and without difficulty.

  In addition, when the PID value detection method of the present invention is used, it is possible to separate a PES packet including video data and a PES packet including audio data at high speed without depending on PAT or PMT information.

  According to the present invention, multimedia data compressed and multiplexed by the MPEG2 system and transmitted as a TS (transport stream) is received by a receiver, and each video / audio data not fixed is received from the received TS. Obtains information on PID (packet identifier) value, refers to the obtained PID value, separates video and audio at high speed with low waiting time, and loads the decoded video and audio data on memory It is possible to provide a technology for recording while reducing, and to realize a small and high-performance stream data receiver and a portable terminal having digital terrestrial broadcasting (1-segment broadcasting) reception, high-speed playback, and recording functions. .

  Next, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a main configuration of an example of a stream data receiver of the present invention (including a PID value detection circuit of the present invention).

  The major feature of this stream data receiver is that the header and payload of a transport stream packet (TS packet) compliant with the MPEG2 standard received without using PAT or PMT information is brute force, and A complex analysis across the header and payload is performed, and as a result of the analysis, a PID value of desired multimedia data (that is, video data and audio data) is detected, and the detected PID value is referred to. To identify a TS packet having the PID value from a number of TS packets included in the transport stream (TS), and to separate (select) the PES (packetized elementary stream) packet included in the TS packet. It is.

  As illustrated, the stream data receiver of the present invention includes a radio antenna AN1, a receiving unit 100, a PES-PID detecting unit 102 (payload start unit indicator checking unit 130, payload head checking unit 131, stream identifier, A check unit 132, a PID value extraction unit 133, a PES packet separation unit 104, a recording / playback control unit 106, and a memory (semiconductor memory, hard disk, and various recording media such as an SD card). 108), a video decoding unit 110, an audio decoding unit 112, a display control unit 114, an audio reproduction unit 116, a display (liquid crystal display or the like) 118, and a speaker 120.

  The receiving unit 100 receives, for example, terrestrial digital broadcasting (having the same TV frequency band (UHF band) as analog broadcasting) modulated by OFDM, which is a multicarrier modulation method.

  The receiving unit 100 outputs a transport stream signal (MPEG2-TS) compliant with MPEG2. The MPEG2-TS is supplied in parallel to the PES packet separation unit 104 and the PES-PID detection unit 102 arranged in the preceding stage.

  The PES-PID detection unit 102 performs an original brute force analysis for each TS packet without using information of a PAT (program association table) or PMT (program map table), and based on the analysis result. Detect (extract) the PID value of the TS packet including video data and audio data.

  The outline is as follows. That is, the payload start unit indicator check unit 130 of the PES-PID detection unit 102 determines whether or not a PES packet may be included, and then the payload head check unit determines the PES packet from the value at the beginning of the payload. Next, the stream identifier check unit 132 confirms that video data or audio data is included, and the PID value extraction unit 133 checks the PID included in the header of the TS packet. The value is extracted as a PID value of a TS packet including video data or audio data. The detection of the PID value will be specifically described later with reference to FIGS.

  The PID values of video data and audio data detected by the PES-PID detection unit 102 are sent to the PES packet separation unit 104.

  The PES packet separation unit 104 refers to the PID values of a number of TS packets included in the received MPEG2-TS, and extracts a TS packet having the same PID as that sent from the PES-PID detection unit 102. Next, the PES packet inserted in the payload of the extracted TS packet having the same PID value is extracted and reassembled to separate the video PES (V-PES) and the audio PES (A-PES). Output.

  Subsequently, the video PES (V-PES) is decoded by the video decoding unit 110, and the audio PES (A-PES) is decoded by the audio decoding unit 112.

  The decoded video data is sent to the display control unit 114, and a moving image is displayed on the display 118 under the control of the display control unit 114. The decoded audio data is sent to the audio playback unit 116, and the audio playback unit 116 plays back the audio signal. As a result, sound is output from the speaker 120.

  When the V-PES and A-PES separated by the PES packet separation unit are once recorded in the memory 108, the V-PES and A-PES are sent to the recording / reproduction control unit 106. When recording the V-PES and A-PES in the memory 108, information on the PAT (program association table) and PMT (program map table) and information on the PID value detected by the PES-PID detection unit 102 are not recorded.

  In recent years, stream data receivers have many types (recordable / reproducible types) having a recording function as well as a multimedia signal reproduction function. A conventional stream data receiver needs to record the PID (program association table) or PMT (program map table) or the PID value of the detected TS packet separately when the received TS packet is once recorded. Therefore, the size of the recording file is increased, and it is necessary to secure a recording area (various recording media such as a memory, a hard disk, and an SD card) for storing the large recording file. On the other hand, the stream data receiver of the present invention has a function of analyzing the TS packet itself to be recorded and obtaining the PID value of the TS packet including video data / audio data. There is no need to record PMT or information of the acquired PID value separately. Therefore, it is possible to reduce the size of the recording file, which is advantageous in terms of cost reduction, size reduction, and power consumption reduction of the receiver.

  Next, the PID value detection procedure in the PES-PID detection unit 102 will be specifically described with reference to FIGS.

  FIG. 2 is a diagram showing a data structure of a TS packet conforming to the MPEG2 standard.

  As shown in the figure, the TS packet has an overall length of 188 bytes (fixed length), the first 4 bytes are the TS header, and the remaining 184 bytes are the data portion 9.

  The TS header includes a synchronization byte (8 bits) 1, a transport error indicator (1 bit) 2, a payload unit start indicator (1 bit) 3, a transport priority (1 bit) 4, and a PID (packet (Identifier: 13 bits) 5, transport scramble control (2 bits) 6, adaptation field control (2 bits) 7, and continuity index (4 bits).

  The data portion (184 bytes) 9 is provided with a payload and an adaptation field (may not be provided).

  FIG. 4 is a diagram for explaining the number of bits of each data included in the TS packet of FIG. 2 and the meaning of information included in the data.

  In FIG. 4, what should be particularly noted is the information that the payload unit start indicator (reference numeral 3 in FIG. 2) has. That is, if the payload unit start indicator 3 is “1”, “the start point of the payload is either the start point of the PES packet or a pointer indicating the start point of the section”. It becomes clear that. That is, if the payload unit start indicator 3 is “1”, “a PES (packetized elementary stream) packet may exist at the start point of the payload”.

  Next, the structure of a PES (packetized elementary stream) packet inserted into the payload will be described. FIG. 5 is a diagram for explaining the number of bits of each data included in a PES (packetized elementary stream) packet and the meaning of the data.

  Here, it should be noted that the packet start code prefix at the head of the header of the PES packet is “000001 (hexadecimal notation)”. That is, if the value at the beginning of the payload is “000001”, it means that a PES packet exists in the payload.

  Also noteworthy is that the value of the stream identifier following the packet start code prefix is determined according to the type of data. That is, the video data in the MPEG2 format is “1110xxxx (hexadecimal notation)”, and the audio data in the MPEG2 format is “FA (hexadecimal notation)”.

  In other words, if the stream identifier is “1110xxxx (hexadecimal notation)”, it is found that the data existing in the payload is video data. Similarly, the stream identifier is “FA (16 "Hexadecimal notation" "means that the data present in the payload is found to be video data.

  In this way, it is possible to determine whether the data present in the TS packet is video data or audio data by complex analysis of the TS packet header and payload.

  If it is found that the TS packet has video data or audio data, the TS having video data or audio data is referred to by referring to the value of the PID (reference numeral 5 in FIG. 2) of the header of the TS packet. The PID value of the packet can be detected.

  For example, if the analysis shows that the data included in the TS packet is audio (1) data and the PID value of the TS packet is “0010”, the TS packet including the audio (1) data PID value = “0010” can be detected. If the PID value can be detected, the TS packet including the audio (1) data is extracted by referring to the PID value of the received TS packet in the next processing and extracting all the values having “0010”. Can be distinguished from other TS packets. This also means that a TS packet including video data and a packet including audio data can be selectively separated.

  FIG. 3 is a diagram showing the data structure of a TS packet for explaining the procedure of PID value detection in the PID value detection method of the present invention. In FIG. 3, the same reference numerals are used for parts common to FIG. In the TS packet of FIG. 3, an adaptation field 9 a and a payload 9 b are provided in the data portion 9.

  As described above, the TS packet is analyzed by determining the possibility of the presence of the PES packet by checking the payload unit start indicator 2 (step S1) and confirming the presence of the PES packet by checking the packet start code prefix 11 in the payload header. (Step S2), confirmation of the validity of the data by checking the stream identifier 13 in the payload header (Step S3), and confirmation of whether the data is any video / audio data after the validity has been confirmed ( This is performed by sequentially performing a series of steps of step S4) and extraction of the PID value of the TS packet (step S5).

  As described above, a TS packet analysis requires a plurality of steps including checking of both the header and the payload. However, in the current mobile phone terminal or the like where a high-speed clock is used, such a process is easy. Can be implemented.

  For example, processing of each unit (reference numerals 130 to 133) included in the PES-PID detection circuit 102 of FIG. 1 is pipelined, and TS packet latching, header analysis, and payload analysis processing are performed in synchronization with a high-speed clock. Thus, efficient processing can be performed.

  Further, in the PID value detection method of the present invention, there is no need to fix the PID value of a packet or the like including video data as in the prior art, so there is no problem in flexibility and expandability. Therefore, there is no need to transmit the PID value to the receiving side, and there is an advantage that no extra procedure is generated.

  FIG. 6 is a flowchart showing a procedure of PID value detection in the PID value detection method of the present invention.

  That is, the payload unit start indicator check unit (reference numeral 130 in FIG. 2) indicates that when the value of the payload unit start indicator 3 is “1”, the payload start point may be the start point of the PES packet. Determine (step S1).

  Next, when the packet start code prefix 11 starts with “000001”, the payload header check unit (reference numeral 131 in FIG. 1) determines that the PES packet is included in the payload (step S2).

  Next, the stream identifier check unit (reference numeral 132 in FIG. 1) checks an identifier for which the stream identifier 13 is valid (that is, indicates the presence of video data or audio data) (step S3).

  When the stream identifier 13 is “1110xxxx” indicating video data (step S4-1), the PID value for the video PES (V-PES) is extracted (step S5-1).

  Similarly, when the stream identifier 13 is “FA (hexadecimal notation)” and indicates audio data (step S4-2), the PID value for the audio PES (A-PES) is extracted (step S5). -2).

  Next, the effect of the present invention will be specifically described.

  FIG. 7 is a diagram showing an example of the contents and types of PES packets included in a transport stream (MPEG2-TS) compliant with MPEG2.

  As shown in the figure, MPEG2-TS contains TS packets TS1 and TS3 including VIDEO1 (video 1) data with a PID value "0020" and AUDIO1 (audio 1) data with a PID value "0010". TS packet TS2 including TS packet TS2, TS4 including PAT (program association table) whose PID value is fixed to "0000", and TS including PMT (program map table) whose PID value is fixed to "1FCB" Packet TS6.

  When the TS packet (TS5) including PAT is analyzed, the PID value of the TS packet including PMT, VIDEO1, and AUDIO1 can be obtained as illustrated. Further, when the TS packet (TS6) including the PMT is analyzed, the PID value of the TS packet including VIDEO1 and AUDIO1 can be known as illustrated.

  FIG. 8 is a diagram showing an example of packet arrangement in MPEG2-TS (MPEG2 transport stream) for explaining the effect of the PID value detection method of the present invention. FIG. 8A shows a conventional method as a comparative example. The figure for demonstrating the PID value detection method, (b) is a figure for demonstrating the PID value detection method of this invention.

  In the case of MPEG2-TS as shown in FIG. 8A, the data of VIDEO1 and AUDIO1 cannot be separated / extracted unless packets (TS5, TS6, TS9) including PAT and PMT are sequentially reproduced.

  On the other hand, in the PID value detection method of the present invention, as shown in FIG. 8B, the VIDEO1 packet (TS1) and the AUDIO1 packet (TS4) are analyzed, and the PID value is directly extracted from the packet. can do. Therefore, extraction / reproduction processing of packets (TS5, TS6, TS9) including PAT and PMT is not necessary, and accordingly, the separation processing of video data and audio data can be accelerated.

(Second Embodiment)
In the present embodiment, the configuration of a mobile phone terminal capable of receiving 1-segment broadcasting will be specifically described.

  In Japan's terrestrial digital broadcasting, the ISDB-T system is adopted. That is, as shown in FIG. 10, the 6 Mhz band (corresponding to one channel of conventional analog broadcasting) broadcast from the broadcast station 290 is divided into 13 subbands and operated. Each subband is called a segment. For example, high-quality HD (high definition) transmission for the HDTV 304 installed in the house 300 can be implemented using all 12 segments. In addition, it is possible to provide three programs of SD (standard definition) broadcasting for the SD television 302 using four segments, and flexible program organization is possible.

  One segment out of 13 segments is reserved for mobile broadcasting, and using this one segment provides simple video broadcasting for mobile phones and PDAs. Broadcast).

  In order to receive 1-segment broadcasting at a mobile phone terminal, a broadcast stream (TS) compressed and multiplexed in MPEG2 is received, various media data is separated from the broadcast stream (TS), and media data is reproduced. A function to present is required, and a function to record media data as necessary is also required.

  FIG. 9 is a block diagram showing a system configuration of a mobile phone terminal incorporating a terrestrial digital broadcast tuner equipped with the PID value detection circuit of the present invention.

  As shown in the figure, this mobile phone terminal includes antennas AN1 and AN2, a mobile phone front end 210 (having a communication unit 212 and a communication control unit 214), a terrestrial digital broadcast tuner unit 220 (a chip tuner 222, A channel decoder 224), a broadcast phone platform 230 (including a broadcast viewing application unit 232, a CPU 234, a mobile phone application unit 236, a recording / playback control unit 240, and a memory 250), a display unit 260, And a speaker 270.

  The broadcast viewing application unit 232 includes a broadcast stream control unit (not shown) in charge of demultiplex processing of the multiplexed transport stream, and this part includes the PID value detection circuit ( 1 and the PES packet separation unit (reference numeral 104 in FIG. 1) are used.

  For example, since users of mobile terminals are accustomed to enjoying moving images using the communication function, it is necessary to prompt the user for quick cueing even when receiving 1-segment broadcasting (terrestrial digital broadcasting for mobile terminals). Disadvantages such as creating an irritating feeling occur. In addition, since mobile terminals are required to be small, light, and consume low power, it is inherently a burden to install an advanced tuner broadcast stream receiving application for receiving 1-segment broadcasting. Is big.

  However, if the PID detection circuit of the present invention (reference numeral 130 in FIG. 1) is used, it is not necessary to reproduce the PAT or PMT information, so that it is possible to reproduce a video signal / audio signal much faster than before. Thus, the waiting time until reproduction can be reduced.

  FIG. 11 is a diagram showing an example of a packet arrangement in MPEG2-TS for explaining the reason why high-speed video signal / audio signal reproduction is possible in the mobile phone terminal shown in FIG.

  Conventionally, in the PAT and PMT unreceived sections (the first half section in FIG. 11), the packet (V-0) including video data and the packet (A-0) including audio data cannot be separated / extracted. In the mobile phone terminal of the present invention, a necessary PID value can be acquired directly from a packet (V-0) including video data and a packet (A-0) including audio data. Therefore, it is possible to detect a necessary PID value without waiting for the playback of the PAT or PMT.

  In the mobile phone terminal of FIG. 9, the recording / playback control unit 240 does not separately record PAT or PMT information, acquired PID value information, or the like when TS packets are recorded. That is, since the mobile phone terminal of the present invention has a function of analyzing the TS packet itself to be recorded and obtaining the PID value of the TS packet including the video data / audio data, even when the TS packet is recorded, There is no need to separately record PAT and PMT information or information on the acquired PID value.

  Therefore, the size of the recording file can be reduced. Therefore, according to the present invention, it is possible to promote the realization of a small-sized, light-weight, low power consumption and high-performance portable terminal having a terrestrial digital broadcast receiving function.

  As described above, PAT (Program Association Table) and PMT (Program Map Table) are performed by performing a complex analysis including checking of both the header and payload of the TS packet by the PID value detection circuit of the present invention. It is possible to detect the PID value of a TS packet including video data or audio data quickly and efficiently without relying on the above information.

  Further, in the technology of the present invention, there is no need to fix the PID value of a packet including video data as in the prior art, so there is no problem in flexibility and expandability. Since there is no need to convey the message to the receiving side, no extra procedure is required.

  In addition, the PID value detection circuit of the present invention is arranged in the preceding stage of the PES packet separation unit, and the PES packet separation using the detected PID value is performed, so that the video signal / audio signal can be separated very quickly. And reproduction can be realized without difficulty.

  Further, according to the present invention, there is no problem of packet discard until the PAT or PMT is reproduced as in the prior art.

  Further, the stream data receiver of the present invention has a function of analyzing the TS packet itself to be recorded and obtaining the PID value of the TS packet including video data / audio data. There is no need to separately record information on the PMT, information on the acquired PID value, or the like. Therefore, it is possible to reduce the size of the recording file, which is advantageous in terms of cost reduction, size reduction, and power consumption reduction of the receiver.

  Further, according to the portable terminal of the present invention, high-speed video / audio signals can be reproduced, the waiting time until reproduction can be reduced, and the size of the recording file at the time of recording can be reduced. Become. Therefore, according to the present invention, it is possible to promote the realization of a small-sized, light-weight, low power consumption and high-performance portable terminal having a terrestrial digital broadcast receiving function.

  Further, according to the PID value detection method of the present invention, it is possible to determine the possibility of the presence of a PES packet by checking the payload unit start indicator, to confirm the presence of the PES packet by checking the packet start code prefix of the payload header, Perform a complex analysis step that includes checking both the header and payload, confirming the presence of either video / audio data by checking the stream identifier, extracting the PID value of the TS packet, and It becomes possible to detect the PID value of the TS packet including the multimedia data at high speed and without difficulty.

  In addition, when the PID value detection method of the present invention is used, it is possible to separate a PES packet including video data and a PES packet including audio data at high speed without depending on PAT or PMT information.

  According to the present invention, multimedia data compressed and multiplexed by the MPEG2 system and transmitted as a TS (transport stream) is received by a receiver, and each video / audio data not fixed is received from the received TS. Obtains information on PID (packet identifier) value, refers to the obtained PID value, separates video and audio at high speed with low waiting time, and loads the decoded video and audio data on memory It is possible to provide a technology for recording while reducing, and to realize a small and high-performance stream data receiver and a portable terminal having digital terrestrial broadcasting (1-segment broadcasting) reception, high-speed playback, and recording functions. .

  Note that the present invention can also be applied to detection of PID values for data other than video data and audio data included in a TS packet.

  The present invention performs a complex analysis that includes checking both the header and payload of a TS packet, thereby speeding up the PID value of a TS packet containing video data or audio data without relying on PAT or PMT information. It can be detected efficiently and contributes to the realization of a receiver having a digital terrestrial broadcasting tuner capable of high-speed cueing. Therefore, the PID of desired multimedia data from the MPEG2 standard TS can be obtained. It is suitable for use in portable terminals (including mobile phone terminals, PDA terminals, portable small computers, etc.) equipped with a PID value detection circuit for detecting values, a stream data receiver, and a terrestrial digital broadcast tuner.

The block diagram which shows the main structures of an example of the stream data receiver (including the PID value detection circuit of the present invention) of the present invention The figure which shows the data structure of TS packet based on MPEG2 standard The figure which shows the data structure of TS packet for demonstrating the procedure of PID value detection in the PID value detection method of this invention The figure for demonstrating the number of bits of each data contained in TS packet of FIG. 2, and the meaning of the information which the data has The figure for demonstrating the bit number of each data contained in a PES (packetized elementary stream) packet, and the meaning which the data has The flowchart which shows the procedure of the PID value detection in the PID value detection method of this invention The figure which shows the example of the content and kind of PES packet contained in the transport stream (MPEG2-TS) based on MPEG2 It is a figure which shows the example of an arrangement | sequence of the packet in MPEG2-TS (MPEG2 transport stream) for demonstrating the effect of the PID value detection method of this invention, (a) is the PID value detection method by the conventional method as a contrast FIG. 5B is a diagram for explaining the PID value detection method of the present invention. The block diagram which shows the system configuration | structure of the mobile telephone terminal which incorporates the digital terrestrial broadcasting tuner which mounts the PID value detection circuit of this invention. Diagram for explaining the hierarchical transmission system in terrestrial digital broadcasting in Japan The figure which shows an example of the packet arrangement | sequence in MPEG2-TS for demonstrating the reason which reproduction | regeneration of a high-speed video signal / audio signal is attained in the mobile telephone terminal shown by FIG.

Explanation of symbols

AN wireless antenna 100 reception unit 102 PES-PID detection unit 130 payload start unit indicator check unit 131 payload head check unit 132 stream identifier check unit 133 PID value extraction unit 104 PES packet separation unit 106 recording / reproduction control unit 108 memory (semiconductor memory) And various recording media such as SD cards in addition to hard disks)
DESCRIPTION OF SYMBOLS 110 Video decoding part 112 Audio decoding part 114 Display control part 116 Audio reproduction part 118 Display (liquid crystal display etc.)
120 Speaker 210 Mobile Phone Front End 212 Communication Unit 214 Communication Control Unit 220 Terrestrial Digital Broadcast Tuner Unit 222 Chip Tuner 222
224 channel decoder 230 broadcast telephone platform 232 broadcast viewing application section 234 CPU
236 Mobile phone application unit 240 Recording / playback control unit 250 Memory 260 Display unit 270 Speaker

Claims (8)

A PID value detection circuit that analyzes information included in a transport stream packet (TS packet) and detects a PID value of a TS packet including video data or audio data;
A payload unit start indicator determination unit that refers to the value of the payload unit start indicator in the header of the TS packet and determines the possibility that the start point of the payload is the start point of a packetized elementary stream packet (PES packet);
When it is determined that the start point of the payload may be the start point of a packetized elementary stream packet (PES packet), by referring to the packet start code prefix of the payload header in the TS packet, A payload header determination unit that determines whether or not a PES packet is included in the payload;
A stream identifier determination unit that determines whether or not the stream identifier in the header of the payload in the TS packet indicates video data or audio data when it is determined that a PES packet is included in the payload; ,
A PID value extraction unit that extracts the PID value of the TS packet as the PID value of the TS packet including the video data or audio data when it is determined that the stream identifier indicates video data or audio data; ,
A PID value detection circuit comprising: The PID value detection circuit according to claim 1,
The payload unit start indicator determination unit determines that there is a possibility that the start point of the payload is the start point of the PES packet when the value of the payload unit start indicator is “1”.
The payload header determination unit determines that a PES packet is included in the payload when the packet start code prefix starts with “000001”.
The stream identifier determination unit determines that the stream identifier is video data when the stream identifier is a value assigned to video data, and determines that the stream identifier is audio data when the stream identifier is a value assigned to audio data. To
A PID value detection circuit. A PID value detection circuit according to claim 1 or 2,
2. The PID value detection circuit according to claim 1, wherein the transport stream packet conforms to the MPEG2 standard. A receiving unit for receiving a transport stream (TS);
The PID value detection circuit according to any one of claims 1 to 3, wherein the PID value is detected by analyzing information on each of a plurality of TS packets constituting the TS received by the receiving unit. ,
A TS packet having a PID value for the video data or audio data extracted by the PID value detection circuit is selected from the plurality of TS packets received by the receiving unit. A PES packet separating unit that separates a PES packet including audio data and a PES packet including audio data;
A decoding unit for decoding video data and audio data from each separated video and audio PES packet;
A stream data receiver. The stream data receiver according to claim 4, wherein
The recording / reproducing control unit further controls recording of the information of each separated video and audio PES packet and the reproduction of the recorded information. The recording / reproducing control unit performs recording of the information of the PES packet. A stream data receiver characterized by not recording information on PAT (program association table) and PMT (program map table) and information on the PID value detected by the PID detection circuit. The stream data receiver according to claim 4 or 5,
The stream data receiver is a portable terminal including a terrestrial digital broadcast tuner as the receiver. By analyzing the information contained in the transport stream packet (TS packet), the PID value of the TS packet containing video data or audio data without referring to the information in the PAT (program association table) and PMT (program map table) A PID value detection method for detecting
A first step of determining a possibility that a payload start point is a start point of a packetized elementary stream packet (PES packet) with reference to a value of a payload unit start indicator in a header of the TS packet;
When it is determined that the start point of the payload may be the start point of a packetized elementary stream packet (PES packet), by referring to the packet start code prefix of the payload header in the TS packet, A second step of determining whether a PES packet is included in the payload;
A third step of determining whether or not the stream identifier in the header of the payload in the TS packet indicates video data or audio data when it is determined that a PES packet is included in the payload; ,
A fourth step of extracting a PID value of the TS packet as a PID value of a TS packet including video data or audio data when it is determined that the stream identifier indicates video data or audio data; ,
A PID value detection method comprising:   A TS packet having a PID value for the video data or audio data detected by the PID value detection method according to claim 6 is selected from a plurality of received TS packets, thereby including video data. A PES packet separation method for separating a PES packet and a PES packet including audio data.

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