JP5452428B2 - Stream dividing apparatus and receiving apparatus - Google Patents

Description

  The present invention divides an MPEG-2 TS (Transport Stream) into two on the transmission side, transmits the two divided into two independent transmission paths, and re-combines them into one MPEG-2 TS on the reception side. The present invention relates to a dividing device and a receiving device.

  MPEG-2 TS can multiplex and transmit a plurality of components such as video signals and audio signals compressed by clock information and information source coding technology, data of data broadcasting, PSI / SI, etc. into one stream. it can. Each component is stored in a fixed-length packet (hereinafter referred to as “TSP”) identified by an identifier “pid”. MPEG-2 TS has a function of synchronizing and operating an encoder that generates a compressed signal by encoding video signals and audio signals, and a decoder that decodes the signals and reproduces the video signals and audio signals. . The encoder intermittently stores the sample value of the clock referenced by the encoder as a PCR (Program Clock Reference) in the TSP and transmits it. The receiving side uses the received PCR to synchronize the decoder clock with the encoder clock. Although the encoder and the decoder can be synchronized by PCR, in order to keep the decoder clock stable, it is necessary to reduce the transmission delay jitter of the TSP transmitting the PCR.

  In MPEG-2 TS, a plurality of video and audio signals can be multiplexed and transmitted on a single MPEG-2 TS at the same time. For example, in satellite digital broadcasting, video and audio of two channels are multiplexed and transmitted on one TS.

  In order to divide and transmit an MPEG-2 TS stream in which a plurality of components are multiplexed on two transmission lines, it is necessary to divide and combine the MPEG-2 TS.

  A stream can be divided by extracting only a specific component from an MPEG-2 TS including a plurality of components and creating two MPEG-2 TSs having a small bit rate. As an example of the stream division, a partial TS (partial TS) in which the TSP storing the video / audio signal of an unnecessary channel is deleted from the MPEG-2 TS including the video / audio signal of two channels, Recording is done.

  An MPEG-2 TS created by deleting a part of TSP in this way generally has a VBR (Variable Bit Rate) property in which the bit rate greatly varies. For transmission of the VBR stream, it is necessary to secure a transmission path for the maximum bit rate, and there is a problem that the band use efficiency is poor.

  Therefore, conversion to a CBR (Constant Bit Rate) signal that smoothes the bit rate of the MPEG-2 TS is performed in order to increase the bandwidth utilization efficiency. Since the transmission time of the TSP changes with the smoothing process and transmission jitter occurs, it is necessary to correct the value of the PCR time stamp for smoothing.

  Conversely, when a plurality of MPEG-2 TSs are added to form one MPEG-2 TS, jitter accompanying the merge occurs, and therefore it is necessary to absorb the jitter or correct the time stamp value. In addition, it is necessary to match the timing of the components transmitted in each MPEG-2 TS so that the decoding times match. For this reason, it is necessary to match the timing of the correction of the value of the PCR time stamp and the time order of the TSPs belonging to the two streams to be combined.

  In this way, when the MPEG-2 TS is divided into two parts, divided into two transmission lines and transmitted, and combined again into one MPEG-2 TS on the receiving side, timing adjustment and division / combination processing are performed. It was necessary to correct the value of the PCR timestamp after

  There is a terrestrial digital broadcast ISDB-T system as a system that transmits a single MPEG-2 TS stream divided into a plurality of layers. ISDB-T has the ability to divide and transmit MPEG-2 TS into a plurality of layers (see, for example, Non-Patent Document 1).

  In ISDB-T, MPEG-2 TS is transmitted with a multiplex frame composed of a number of transport stream packets (TSP) determined by a mode and a guard interval ratio as a basic unit. In ISDB-T, the arrangement of TSPs on this multiplex frame is fixed in advance for each layer to be transmitted.

  When only a part of the hierarchy is received like a one-segment receiver, the TSP time interval changes like the partial TS, and transmission jitter occurs.

  Therefore, in digital terrestrial broadcasting, a TSP with a PCR time stamp has an operational restriction of multiplexing one in mode 1, two in mode 2, and only four in mode 3 per service in one multiplex frame period. By doing so, the transmission cycle of a TSP having a PCR time stamp is made constant even if only a part of layers is received. Due to this operational limitation, a predetermined number of PCR time stamps must be transmitted for each multiplex frame, but correction of the PCR time stamp value is not required even when only a part of the layers is received.

  In this way, instead of re-multiplexing a stream that has been divided into two and retransmitted into one stream, each stream is played back independently and played back at the same playback timing to produce the same effect. Is known (see, for example, Non-Patent Document 2).

  In this technique, it is necessary to control the decoders of the respective components from the outside so as to operate synchronously. However, a general decoder LSI does not provide a function for such external synchronization operation. There is.

ARIB STD-B31 Version 1.8 Digital Terrestrial Television Method Transmission System, 2009 K. Matsumura, “Personalization of Broadcast Programs using Synchronized Internet Content”, IEEE International Conference on Consumer Electronics 2010, 2010

  In terrestrial digital broadcasting, since it is a system that transmits a plurality of layers as a unit, the transmission path of each layer through which MPEG-2 TS is transmitted separately is a synchronous line in which the transmission side and the reception side are synchronized, These are transmission lines synchronized with a common clock, and their delays are completely matched. For this reason, TSPs transmitted in different layers can be handled as one multiplexed frame.

  However, when one MPEG-2 TS is transmitted through two independent transmission lines, one is a digital broadcast transmission line and the other is an Internet transmission line, one is a synchronous line and the other is an asynchronous line. It becomes a packet communication network, these delays are different, and the Internet is also a transmission path that can generate large jitters. For this reason, the ISDB-T technique cannot be applied as it is.

  Therefore, in order to divide and transmit MPEG-2 TS to two independent transmission paths and combine it again into one MPEG-2 TS on the receiving side, the timing adjustment between the two transmission paths and the division / synthesis process Later correction of the value of the PCR timestamp was necessary.

  In view of the above problems, the object of the present invention is to divide an MPEG-2 TS (Transport Stream) into two parts on the transmission side and transmit the divided MPEG-2 TS on two independent transmission paths. -2 To provide a stream dividing device and a receiving device for combining with TS.

That is, the stream splitting device of the present invention is a stream splitting device that splits an input transport stream (TS) into two transmission paths, a main transmission path and a sub-transmission path. TSP) is identified as a predetermined type, and the identification result is output to the stream structuring unit together with the TSP, and the TSP input from the stream discriminating unit is temporarily stored in the memory, and then the identification is performed. result, by using the structure information for discriminating the type of order of the pre-defined TS slot in the transmission block, and between the TSP with P CR timestamp, always a ratio of the number of TSP sent in the main transmission path constant so as to make the corrections including reordering and null packets insertion and deletion of the TSP, perform correction of the PCR time stamp associated with the modification, the T S A stream structuring unit that performs the structure, a TSP (TYPE_m) that is transmitted on the main transmission path without a PCR time stamp, and a TSP of the TS structured by the stream structuring unit according to the structure information, and a PCR Regardless of the presence or absence of a time stamp, the TSP (TYPE_t) transmitted on the main transmission path and the TSP (TYPE_s) transmitted on the sub transmission path are separated into three types, with respect to the TSP of the TYPE_m and the TSP of the TYPE_t. A stream demultiplexer for outputting the identification information of the transmission block for identifying the TSP of the TYPE_s and the transmission block for the sub-transmission path, and performing output for the main transmission path with the TSP interval uniformized It is characterized by that.

  Further, in the stream dividing apparatus according to the present invention, the stream separation unit outputs a PCR time stamp value of a TSP having a PCR time stamp in the transmission block and position information indicating a TS slot position in the transmission block. It further has these.

In addition, the receiving apparatus of the present invention receives a TSP that is obtained by dividing one transport stream (TS) into two transmission paths, ie, a main transmission path and a sub-transmission path, and reconfigures it into the one TS. A TSP (TYPE_m) that is transmitted on the main transmission line without a PCR time stamp and a TSP (TYPE_t) that is transmitted on the main transmission line regardless of the presence or absence of the PCR time stamp. ) And TSP (TYPE_s) transmitted on the sub-transmission path, and the TSP of TYPE_m and the TSP of TYPE_t are transmitted on the main transmission path with a uniform TSP interval, identification information of the transmission blocks for identifying the TSP and the transmission block of TYPE_s are defined to be transmitted by the sub transmission path, the one TS is, TSP After being temporarily stored in the memory, using the identification result of the identification to a predetermined type of TSP, and structural information to determine the order of the types of pre-defined TS slot in the transmission block, and sends the main transmission line Modifications including reordering of TSPs and addition and removal of null packets have been performed so that the ratio of the number of TSPs is always constant, and PCR time stamps have been corrected in accordance with the modification, and transmitted on the main transmission line. a main signal receiving section for receiving the TSP was, and fuchsin No. reception section that receives identification information of the transmission blocks for identifying the transmitted TSP and transmission blocks sub-transmission line, according to the structure information, The TSP received via the main transmission path is stored in the TS slot of TYPE_t and the TS slot of TYPE_m, and the TSP including the PCR time stamp is stored. If the type of the TS slot is not TYPE_t, the arrangement of the transmission block is modified so that the TS slot at the TSP storage position is TYPE_t, and the TSP received via the sub-transmission path is the TYPE_s of the transmission block. A stream synthesis unit that sequentially stores the TS slots of the TYPE_s of the transmission block according to the identification information of the transmission block before receiving all the TS slots of the TYPE_s in accordance with the identification information of the transmission block. When it is determined that the end of the TSP transmission block to be reached is reached, a null packet is stored in the TS slot of the subsequent TYPE_s in this transmission block, and the one TS is synthesized.

  In the receiving apparatus of the present invention, the stream synthesizing unit extracts the identification information of the transmission block for the TSP received from the main transmission path, stores the transmission block identification information in a predetermined transmission buffer for each transmission block, and the sub-transmission path Means for receiving and extracting transmission block identification information from the transmission block, and storing the TSP received from the sub-transmission path in a transmission block storage area that matches the transmission block identification information in the transmission buffer. Features.

  Also, in the receiving apparatus of the present invention, the stream combining unit includes the PCR time stamp value of the TSP having the PCR time stamp in the transmission block obtained from the sub-transmission path and the TS in the transmission block defined in advance by the transmission side. When the slot position information is extracted and whether or not the TSP received from the main transmission path has the same value as the PCR timestamp value input from the sub-transmission path, and is determined to have the same value Includes a means for correcting the arrangement of the transmission block so that the TS slot storing the TSP matches the position information of the TS slot in the transmission block.

  The stream dividing apparatus according to the present invention can transmit the TSP transmitted on the main transmission path and the TSP transmitted on the sub transmission path in association with each other even when transmitting on two independent transmission paths.

  In addition, since the ratio of the number of TSPs to be sent on the main transmission line and the TSP to be sent on the sub-transmission line can be kept constant among TSPs having consecutive PCR time stamps, only TSPs received from the main transmission line can be kept. Both the receiving apparatus that decodes and the receiving apparatus that combines and decodes the TSPs received from both transmission paths can generate a stream that does not require modification of the PCR time stamp. In addition, it is possible to eliminate operational restrictions that fix the frequency of PCR time stamp transmission.

  In addition, the receiving apparatus according to the present invention can receive TSPs from the main transmission line and the sub-transmission line, which are two independent transmission lines, and synthesize them into one MPEG-2 TS for use.

It is a figure which shows the structural example of the stream division | segmentation transmission system of one Example by this invention. It is a figure which illustrates the structure information in the stream division | segmentation transmission system of one Example by this invention. It is a figure which shows the example of arrangement | positioning of TS slot of the transmission block in the stream division | segmentation transmission system of one Example by this invention. It is a block diagram of a stream structuring unit of a stream splitting device in a stream splitting transmission system according to an embodiment of the present invention. It is a figure which shows the example of the stream structured by the stream structure part of the stream division | segmentation apparatus in the stream division | segmentation transmission system of one Example by this invention. It is a block diagram of the stream separation unit of the stream division device in the stream division transmission system of one embodiment according to the present invention. It is a block diagram of the stream composition unit of the receiving device in the stream division transmission system of one embodiment according to the present invention. It is a block diagram which shows the modification of the stream structure part of the stream division | segmentation apparatus in the stream division | segmentation transmission system of one Example by this invention.

  Hereinafter, the stream division | segmentation transmission system of each Example by this invention is demonstrated. From the description of the stream division transmission system of the present embodiment, the stream division apparatus and the reception apparatus according to the present invention will also be clarified. First, the stream division | segmentation transmission system of Example 1 is demonstrated.

Example 1
FIG. 1 is a diagram illustrating a configuration example of a stream division transmission system according to an embodiment of the present invention. The stream division transmission system according to this embodiment includes a stream division device 200, a main transmission path transmission device 310, a sub transmission path transmission device 311, and a reception device 400.

  The stream splitting device 200 is a device that inputs MPEG-2 TS encoded data, splits the MPEG-2 TS to the transmission device 310 and the transmission device 311, and outputs the divided data. The stream discrimination unit 210, the stream structuring unit 220, a stream separation unit 230, a discrimination information setting unit 240, and a structure information setting unit 250.

  The stream discriminating unit 210 identifies the type of TSP of the input TS, and outputs the identification result to the stream structuring unit 220 together with the TSP. The type of TSP identified by the stream discriminating unit 210 is designated by a null packet (hereinafter referred to as “TYPE_N”), a TSP having a PCR time stamp (hereinafter referred to as “TYPE_T”), and a pcr_pid of a PMT (Program Map Table). TSP with a designated pid but no PCR timestamp (hereinafter referred to as “TYPE_P”), a TSP (hereinafter referred to as “TYPE_M”) that is not a null packet or a pid specified by pMT_pid of the PMT but is transmitted on the main transmission line And 5 types of TSP (hereinafter referred to as “TYPE_S”) sent on the sub-transmission path.

  The discrimination information setting unit 240 is information for designating and identifying whether a TSP that is not a null packet and is not a pid designated by the PMT pcr_pid is sent to the main transmission line or the sub-transmission line. It is specified that TSPs having the same pid are sent through the same transmission path.

  As an example of the discrimination information, for example, information specifying the pid range of the TSP sent to the main transmission line can be used. Alternatively, the transmission path may be specified by setting the pid condition of the TSP sent to the sub-transmission path. Alternatively, a combination of these may be used, and a transmission path may be designated using the value of the component tag of the PMT instead of pid as a determination condition.

  For example, according to the discrimination information, it is possible to specify a transmission path by setting conditions such that the minimum value of pid transmitted on the sub-transmission path is 0x200 and the maximum value of pid transmitted on the sub-transmission path is 0x3FF.

  The stream structuring unit 220 uses the structure information from the structure information setting unit 250 based on the identification result for the TSP input from the stream discriminating unit 210 in the TSP between the TSPs having the PCR time stamp. Corrections are made to change the order of TSPs and add / remove null packets so that the ratio of the number of TSPs sent on the main transmission line is always constant, and the PCR time stamp is corrected accordingly. -2 Outputs TS. This stream structuring unit 220 modifies the order of the streams and adds or removes null packets, and the correction of the PCR time stamp is referred to as “stream structuring”.

  The structure information is information for determining the order of the types of TS slots defined in advance in the transmission block. The transmission block is composed of a certain number (NB) of TS slots, and each TS slot can store only one TSP. There are three types of TS slots: a TS slot that does not have a PCR time stamp and is transmitted on the main transmission path, or can store only a null packet (hereinafter referred to as “TYPE_m”), a PCR time stamp. TS slot that can be stored in the main transmission path regardless of the presence or absence of TS, or TS slot that can store only null packets (hereinafter referred to as “TYPE_t”), TSP that is transmitted in the sub-transmission path, or TS that can store only null packets One of the slots (hereinafter referred to as “TYPE_s”).

  The number and position of TYPE_m, TYPE_t, and TYPE_s in the transmission block does not change. As an example of the structural information expressing this structuring, a character t is represented by a character string, with the character t corresponding to the TYPE_t, the character m corresponding to the TYPE_m, and the character s corresponding to the TS slot of the TYPE_s. When this representation method is used, the structure information transmission block shown in FIG. 2 can be represented by “tmss”. Also, the structure information transmission block shown in FIG. 3 can be represented by “mtmsmtsmsmtssm”.

  The stream structuring unit 220 performs stream structuring by storing the input TSP in a transmission block and generating TSPs with a certain time interval.

  As shown in FIG. 3, when two or more TS slots of TYPE_t are provided in one transmission block, the stream structuring unit 220 is a section between a certain TYPE_t and the TS slot of TYPE_t transmitted next. The TS slot of TYPE_t is arranged so that the number of TS slots of TYPE_m and the number of TS slots of TYPE_s are equal in any section. Here, the stream structuring unit 220 performs a section from the first TS slot of the transmission block to the TS slot of the first TYPE_t and a section from the TS slot of the last TYPE_t of the transmission block to the last TS slot of the transmission block. Arrange the TS slots of TYPE_t so that the total number of TS slots of TYPE_m and the number of TS slots of TYPE_s are equal to the sections of other transmission blocks.

  With this arrangement, when the section of the TS slot from the position of the TS slot of any TYPE_t to the immediately preceding TS slot of any TYPE_t thereafter is viewed, the ratio of the number of TS slots of TYPE_t and the total number of TS slots of TYPE_m is constant. become. That is, the ratio of the number of TSPs sent on the main transmission path is constant between TSPs having consecutive PCR time stamps.

For example, the example shown in FIG. 3 shows an arrangement example of TS slots in a transmission block composed of 15 TS slots, and “t”, “m”, and “s” in FIG. 3 are TYPE_t, TYPE_m, This indicates that it is a TS slot of TYPE_s. In this example, two TS slots of TYPE_m and TYPE_s are included between TS slots of TYPE_t. Here, assuming that the number of TS slots of TYPE_t, the number of TS slots of TYPE_m, and the number of TS slots of TYPE_s in the transmission block are Nt, Nm, and Ns, respectively, and the transmission period of the transmission block is Tb, the output of the stream structuring unit 220 The TS to be performed is a TS at a constant speed composed of (Nt + Nm + Ns) / Tb TSPs per second.

  FIG. 4 is a block diagram of the stream structuring unit of the stream splitting apparatus in the stream splitting transmission system according to the embodiment of the present invention. The stream structuring unit 220 includes FIFO memories 2201, 2202, and 2203 corresponding to the type of TSP. Each of the FIFOs stores the TSP of TYPE_S, the FIFOm that stores the TSP of TYPE_M, and the TSPs of TYPE_TYPE and TYPE_P. It consists of FIFOtp to store. Further, the stream structuring unit 220 discards the input null packet (TYPE_N), but the other types of input TSP (TYPE_S, TYPE_M, TYPE_T, TYPE_P) are classified into the types in the input order. Accordingly, the data is stored in FIFOs, FIFOm, and FIFOtp.

  Further, the stream structuring unit 220 is the oldest TSP stored in the FIFOs, FIFOm, FIFOtp at regular time intervals according to the order of the types of TS slots defined in advance based on the structure information, or the null packet generating unit 2204. A TSP switching unit 2205 that performs switching control to select a generated null packet and store it in the transmission buffer 2206 is provided.

  When the type of TS slot stored in the transmission buffer 2206 is TYPE_s, the TSP switching unit 2205 selects the oldest TSP stored in the FIFOs. If the FIFOs are empty, the TSP switching unit 2205 is generated by the null packet generation unit 2204. Select a null packet. Similarly, the TSP switching unit 2205 selects the oldest TSP stored in the FIFOtp when the type of the TS slot stored in the transmission buffer 2206 is TYPE_t, but stores it in the FIFOm when the FIFOtp is empty. The oldest TSP (if the FIFOm is empty, a null packet) is selected. Also, when the type of TS slot stored in the transmission buffer 2206 is TYPE_m, the TSP switching unit 2205 stores the oldest TSP stored in the FIFOtp (or the oldest TSP stored in the FIFOm when the FIFOtp is empty). ), But if both FIFOtp and FIFOm are empty, a null packet is selected.

  Here, the stream structuring unit 220 has time stamp correction means (not shown) that corrects the value of the time stamp for the TYPE_T TSP having the time stamp for the time output after being input to the FIFOtp. .

  FIG. 5 is a diagram illustrating an example of a stream structured by the stream structuring unit of the stream splitting device in the stream splitting transmission system according to the embodiment of the present invention. FIG. 5 shows an example of stream structuring that includes three TSPs to be sent to the main transmission line and two TSPs to be sent to the sub-transmission line for each transmission block, and places a TSP having a PCR time stamp at the head of the transmission block. Has been. In FIG. 5, the TYPE_T TSP is represented by “T”, the TYPE_P TSP is represented by “P”, the TYPE_M TSP is represented by “M”, and the TYPE_S TSP is represented by “S”. There are five TSPs in the transmission block, and the time stamp interval is twice this TSP. Therefore, the stream structuring unit 220 can store the input TSP in a transmission block, generate a TSP at a certain time interval, and output the TSP to the stream separation unit 230.

  FIG. 6 is a block diagram of the stream separation unit of the stream division device in the stream division transmission system according to the embodiment of the present invention. The stream separation unit 230 refers to the structure information for determining the order of the types of TS slots defined in advance in the transmission block, and is stored in the TS slot of TYPE_t or TYPE_m from the MPEG-2 TS input from the stream structuring unit 220. The TSP filter processing unit 2301 that extracts the TSPs that are present, the TSP interval equalization processing unit 2302 that performs TSP interval equalization and outputs the TSP interval to the main transmission path transmission device 310, and the structure information, The TS_TS of the TYPE_s TS slot is extracted from the MPEG-2 TS input from the stream structuring unit 220, and transmission block identification information is generated and inserted so that the transmission block delimiter composed of this TS slot can be identified. Sub-transmission path signal extraction processing unit 230 that outputs to sub-transmission path transmitter 311 Provided with a door.

More specifically, the TSP filter processing unit 2301 outputs the TSP stored in the TYPE_t of MPEG-2 TS or the TS slot of TYPE_m input from the stream structuring unit 220 to the transmission device 310 for the main transmission path. To extract for. Here, in order to remove the variation in the TSP interval caused by deleting the TSP of the TS slot of TYPE_s, the TSP interval equalization processing unit 2302 performs a TSP interval equalization process. The TSP interval equalization processing unit 2302 equalizes the TSP interval with the number of TSP transmissions per unit time as (Nt + Nm) / Tb. Since there is no change in the time interval of the TSP having the PCR time stamp, there is no need to correct the PCR time stamp.

  The sub-transmission path signal extraction processing unit 2303 extracts the TSP of the TS slot of TYPE_s from the MPEG-2 TS input from the stream structuring unit 220 and outputs the TSP to the sub-transmission path transmitting apparatus 311. In this processing, the sub-transmission path signal extraction processing unit 2303 may delete the null packet stored in the TS slot of TYPE_s in order to insert the identification information of the transmission block so that the transmission block delimiter can be identified.

  As an example of the identification information of the transmission block, for example, a PCR time stamp included in the transmission block can be used. If the transmission block contains a TSP having a PCR time stamp, the PCR time stamp is used. If the transmission block does not contain a TSP having a PCR time stamp, a special code indicating that the transmission block cannot be specified is transmitted. This is block identification information.

  Further, as another example of the identification information of the transmission block, for example, the transmission time of the transmission block can be used. The transmission time of the first TSP of the transmission block is calculated, and this value can be used as identification information.

  In this way, the stream separation unit 230 extracts the TSP stored in the TS slot of TYPE_t or TYPE_m from the MPEG-2 TS input from the stream structuring unit 220, and uniformizes the TSP interval. Output to transmission device 310 for transmission path and extract TSP of TYPE_s TS slot from MPEG-2 TS, and generate transmission block identification information so that transmission block delimiter composed of this TS slot can be identified Are inserted and output to the sub-transmission path transmitter 311.

  The main transmission path transmission device 310 receives the TSP from the stream separation unit 230 and outputs the TSP to the reception device 400 via the main transmission path. Here, in the TSP transmission between the main transmission path transmission device 310 and the main transmission path reception unit 410 in the reception device 400, the TSP time interval is maintained constant, and the TSP order is also maintained.

  The sub-transmission path transmission apparatus 311 receives the transmission block identification information 2 and the TSP of the TS slot of TYPE_s from the stream separation unit 230, and receives the transmission block identification via the sub-transmission path while maintaining the association for identification. Output to the device 400. In TSP transmission between the sub-transmission-path transmission device 311 and the sub-transmission-path reception unit 411 in the reception device 400, the TSP time interval does not necessarily need to be kept constant, but the TSP order in the transmission block Shall be maintained.

  Next, the receiving device 400 will be described. The receiving apparatus 400 receives the encoded data of the MPEG-2 TS divided by the stream dividing apparatus 200 via the main transmission path transmitting apparatus 310 and the sub transmission path transmitting apparatus 311, and MPEG-2 of each transmission path. This is a device that combines and decodes TS to reconstruct the original MPEG-2 TS.

  The receiving apparatus 400 includes a main transmission path reception unit 410 and a sub transmission path reception unit 411, a stream synthesis unit 420, a decoder 430, and a structure information setting unit 250 that is the same as that on the transmission side. However, in the receiving apparatus 400, instead of including the decoder 430, the MPEG-2TS of the stream synthesizing unit is output, and this is directly or temporarily stored and then input to the external decoder, so that the MPEG-2TS is transmitted to the external decoder. It is also possible to configure so as to perform decryption.

  The main transmission path receiving unit 410 receives the TSP transmitted from the main transmission path transmitting apparatus 310 and transmitted through the main transmission path, and outputs the TSP to the stream combining unit 420.

  The sub-transmission-path receiving unit 411 receives the TSP and the transmission block identification information transmitted from the sub-transmission-path transmitting device 311 and transmitted on the sub-transmission path, and outputs them to the stream synthesis unit 420 while maintaining their association. To do.

  The stream synthesizing unit 420 identifies a transmission block based on the identification information of the transmission block from the TSP received via the main transmission path and the TSP received via the sub transmission path, and uses the structure information to generate one MPEG. -2 TS is synthesized and output to the decoder 430 or the outside. Assume that the same structure information is shared in advance by the stream dividing device 200 and the receiving device 400 for stream composition.

  FIG. 7 is a block diagram of the stream synthesizing unit of the receiving apparatus in the stream division transmission system according to the embodiment of the present invention. The stream synthesis unit 420 creates a transmission block based on the structure information, stores the TSP input from the main transmission path reception unit 410 in the corresponding TYPE_t and TYPE_m TS slots held in the transmission buffer 4201 in the order of input. The TSP input from the sub-transmission path receiving unit 411 is stored in the TS slot of TYPE_s held by the transmission buffer 4201 in the order of input.

  The stream combining unit 420 stores the TSP received from the main transmission path, including the null packet, in the TS slots of TYPE_t and TYPE_m, and the TS slot type when storing the TSP including the PCR time stamp is TYPE_t. If not, the arrangement (timing) of the transmission block can be corrected so that the TS slot at the TSP storage position becomes TYPE_t.

  Further, when the TSP received from the sub-transmission path is input, the stream synthesis unit 420 sequentially stores the TS in the TYPE_s of the transmission block, and in accordance with the transmission block identification information extracted by the transmission block identification information extraction unit 4202. When it is determined that the TSP transmission block segment received from the sub-transmission path is reached before all the TYPE_s TS slots of the transmission block are stored, a null packet is sent to the TS_s TS slot of the subsequent TYPE_s in this transmission block. To store.

  As a result, the TSP time interval is changed due to the newly inserted TSP transmitted on the sub-transmission path with respect to the MPEG-2 TS transmitted on the main transmission path. Since the number of TSPs inserted between TYPE_t in which TSPs with stamps are inserted can always be kept constant, the TSP time intervals with PCR time stamps do not change. For this reason, it is not necessary to correct the PCR time stamp in the receiving apparatus 400.

  The decoder 460 can decode the MPEG-2 TS input from the stream synthesizing unit 420 and output, for example, a video / audio signal constituting the encoded data.

  As a result, on the transmitting side, the conventional receiving apparatus that receives only the MPEG-2 TS of the main transmission path is combined with the receiving apparatus 400 according to the present embodiment that combines using the TSP transmitted on the sub transmission path. In contrast, MPEG-2 TS can be provided in common, and the receiving apparatus 400 can eliminate the need for correction of the PCR time stamp.

  Next, the stream division transmission system according to the second embodiment will be described.

(Example 2)
As in the first embodiment, the stream division transmission system according to the second embodiment includes the stream division device 200 illustrated in FIG. 1, the main transmission path transmission apparatus 310, the sub transmission path transmission apparatus 311, and the reception apparatus 400. Is done.

  However, in the first embodiment, the stream combining unit 420 performs the stream combining assuming that the transmission block identification information from the sub-transmission path can be extracted. However, in the second embodiment, the stream combining unit 420 performs the stream combining. 420 extracts the transmission block identification information for the TSP received from the main transmission path, assuming that there is no transmission block identification information from the secondary transmission path or indicates that the transmission block cannot be specified. And stored in the transmission buffer 4201. That is, the transmission block in the transmission buffer 420 can be specified by the identification information of the transmission block for the TSP received from the main transmission path.

  The method of extracting transmission block identification information for the TSP received from the main transmission path depends on what information is used as the identification information. For example, the PCR time stamp included in the transmission block is used as the identification information. In this case, if there is a TSP having a PCR time stamp in the transmission block, the PCR time stamp is used as an identification information value, and the transmission block is identified by a special code indicating that the transmission block cannot be specified unless there is a TSP having the PCR time stamp. Information value.

  When the transmission time of the transmission block is used as the identification information, the reception time of the first TSP of the transmission block is measured by an STC (System Time Clock) reproduced from the PCR time stamp, and this value is used as the identification information value. be able to.

  That is, in the second embodiment, the transmission block identification information is received and extracted from the sub transmission path, and the TSP received from the sub transmission path is stored in the transmission block storage area that matches the transmission block identification information in the transmission buffer 4201. Is stored.

  When there is no transmission block identification information from the sub-transmission path or the transmission block cannot be specified, the stream combining unit 420 sets the TSP received from the sub-transmission path to the transmission block next to the transmission block stored immediately before. Store sequentially.

  As a result, if the transmission block does not have two or more TYPE_t TS slots, the TSP having the PCR time stamp can be accurately stored in the transmission block. Thus, the original MPEG-2 TS can be accurately synthesized from the TSP transmitted in the above.

  On the other hand, when there are two or more TYPE_t TS slots in the transmission block, the original MPEG-2 TS can be synthesized with an error within the size range of the transmission block.

  Next, the stream division transmission system according to the third embodiment will be described.

(Example 3)
Similarly to the first or second embodiment, the stream division transmission system according to the third embodiment includes the stream division device 200, the main transmission path transmission device 310, the sub transmission path transmission device 311, and the reception device 400 illustrated in FIG. Consists of

  However, in the third embodiment, unlike the first or second embodiment, the sub-transmission path signal extraction processing unit 2303 in the stream separation unit 230 performs the PCR time stamp value of the TSP having the PCR time stamp in the transmission block and the transmission block. Is configured to output position information of the TS slot (see FIG. 6).

  This information is transmitted to the receiving apparatus 400 by using the sub transmission path by the sub transmission path transmitting apparatus 311 and input to the stream combining unit 420. The stream synthesis unit 420 determines whether or not the TSP received from the main transmission path has the same value as the PCR time stamp value input from the sub-transmission path. The arrangement (timing) of the transmission block is corrected so that the TS slot storing the TSP matches the position information of the TS slot in this transmission block.

  For example, when a transmission block whose structural information is represented by “tmmsstmmss” is used, the stream separation unit 230 of the stream division device 200 uses the TSP of TYPE_T whose PCR time stamp value is “T1” as the transmission block. When the MPEG-2 TS stored in the sixth TS slot is input, the information “T1” and “6” together with the TSP stored in the TS slot of TYPE_s is used as the TS slot position information in the transmission block. To the sub-transmission path transmission device 311.

  On the receiving device 400 side, for example, by extracting the position information of the TS slot in the transmission block from the transmission device 311 for the sub transmission path by the transmission block identification information extracting unit 4202, the value of the PCR time stamp received from the main transmission path is obtained. The TSP of “T1” is stored in the “6” TS slot of the transmission block by the transmission buffer 4201, and thereafter, the TSP received from the main transmission path is sequentially stored after the seventh TS slot.

  As a result, even if there are two or more TYPE_t TS slots in the transmission block, the TSP having the PCR time stamp can be stored in the correct position of the transmission block. The TSP transmitted through the sub-transmission path can be accurately synthesized into the original MPEG-2 TS.

  Next, a stream division transmission system according to the fourth embodiment will be described.

Example 4
Similarly to the first or second embodiment, the stream division transmission system according to the fourth embodiment includes the stream division device 200, the main transmission path transmission device 310, the sub transmission path transmission device 311, and the reception device 400 illustrated in FIG. Consists of

  However, in the third embodiment, unlike the first or second embodiment, the stream structuring unit 220 generates and adds the TSP in which the identification information of the transmission block is written as the TSP transmitted on the main transmission path, or Then, the TSP transmitted through the main transmission path is rewritten, and the TSP in which the identification information of the transmission block is written is generated and added. Hereinafter, the TSP in which the identification information is written is referred to as identification information TSP.

  For example, FIG. 8 shows a modification of the stream structuring unit of the stream splitting device in the stream splitting transmission system according to the embodiment of the present invention. The stream structuring unit 220 according to the present embodiment further includes an identification information TSP generation unit 2207 that generates the identification information TSP.

  On the receiving device 400 side, for example, the transmission block identification information extraction unit 4202 can extract transmission block identification information for the TSP received from the main transmission path.

  As a result, a signal that is not included in the original MPEG-2 TS signal input to the stream dividing apparatus 200 is generated and used as the identification information of the transmission block, which increases the degree of freedom in designing the stream division transmission system. it can.

  For example, as an example of the identification information TSP, a sequence number that increases for each transmission block and returns to the minimum value when the maximum value is reached is created as a TSP having a specific pid written in the payload area of the TSP, Insert into TS slot of TYPE_t or TYPE_m.

  On the receiving side, when the stream synthesizing unit 420 receives the TSP having this specific pid, it reads the payload area and determines it as the value of the identification information of the transmission block to which the TSP is assigned. Works as well.

  Note that it is preferable that the bit rate of the TSP transmitted through the main transmission path is limited to a small value by the increase in the bit rate due to the insertion of the TSP. Further, the identification information TSP need not be included in all transmission blocks.

  Next, a stream division transmission system according to the fifth embodiment will be described.

(Example 5)
The stream division transmission system of the fifth embodiment is a modification of the fourth embodiment, and similarly to the above, the stream division apparatus 200, the main transmission path transmission apparatus 310, and the sub transmission path transmission apparatus 311 shown in FIG. And the receiving device 400.

  However, in the fifth embodiment, unlike the fourth embodiment, the identification information TSP generation unit 2207 includes not only the identification information of the transmission block but also the position information of the TS slot of the transmission block in which this TSP is stored. Identification information TSP is generated.

  On the receiving device 400 side, when the stream synthesis unit 420 receives the identification information TSP from the main transmission path, for example, the transmission block identification information extraction unit 4202 reads the position information of the TS slot of the transmission block in which the TSP is stored. Then, the arrangement (timing) of the transmission block is corrected so that the TS slot storing this TSP matches the position information of the TS slot in this transmission block.

  As a result, as in the fourth embodiment, even when there are two or more TYPE_t TS slots in the transmission block, the TSP having the PCR time stamp can be stored in the correct position of the transmission block. The TSP transmitted on the path and the TSP transmitted on the sub-transmission path can be accurately combined into the original MPEG-2 TS.

  Next, a stream division transmission system according to the sixth embodiment will be described.

(Example 6)
The stream division transmission system according to the sixth embodiment is a modification of the fourth embodiment, and similarly to the above, the stream division apparatus 200, the main transmission path transmission apparatus 310, and the sub transmission path transmission apparatus 311 illustrated in FIG. And the receiving device 400.

  However, in the sixth embodiment, when the TSP switching unit 2205 of the stream structuring unit 220 multiplexes the identification information TSP, the TSP switching unit 2205 is always arranged and stored at a fixed position (identification information multiplexing position) of the TS slot of the transmission block. Switching control is performed so that

  On the receiving device 400 side, when the stream synthesizing unit 420 receives the identification information TSP from the main transmission path, the transmission block is arranged so that the TS slot storing the TSP matches the identification information multiplexing position in the transmission block. Correct (timing).

  As a result, similar to the fourth or fifth embodiment, even when there are two or more TYPE_t TS slots in the transmission block, the TSP having the PCR time stamp can be stored in the accurate position of the transmission block. It is possible to accurately synthesize the original MPEG-2 TS from the TSP transmitted on the main transmission line and the TSP transmitted on the sub transmission line.

  According to the present invention, the present invention is preferably applied to a video / audio providing service. For example, it is preferable to use broadcasting for the main transmission path and a communication line for the sub-transmission path. The service provider uses this system to provide video and accompanying audio A by broadcasting. The broadcast receiving apparatus 400 views the video and audio A by receiving this broadcast wave. The service provider provides audio B and audio C accompanying the video separately from audio A at the same time as audio A using a communication line.

  As an example of the combination of the voice A, the voice B, and the voice C, for example, the voice A is a lower-layer voice of the multi-channel voice, the voice B is a middle-layer voice, and the voice C is an upper-layer voice. Furthermore, by adding voice from the communication line, a more realistic service can be provided.

  As another example of the combination of the voice A, the voice B, and the voice C, the voice B and the voice C can be a voice in a language different from the voice A and a commentary voice. By switching and reproducing the sound A, the sound B, and the sound C with the receiving device 400, more various services can be provided.

  According to the present invention, even when transmitting on two independent transmission paths, the TSP transmitted on the main transmission path and the TSP transmitted on the sub-transmission path can be transmitted in association with each other. The transmission efficiency at the time of multiplexing transmission can be improved, and it is useful for the purpose of performing multiplex data transmission using different types of transmission paths.

DESCRIPTION OF SYMBOLS 200 Stream division | segmentation apparatus 210 Stream discrimination | determination part 220 Stream structuring part 230 Stream separation part 240 Discrimination information setting part 250 Structure information setting part 310 Main transmission path transmission apparatus 311 Sub transmission path transmission apparatus 400 Reception apparatus 410 Reception for main transmission path 411 Sub-transmission path receiver 420 Stream synthesizer 430 Decoder 2201 FIFO memory (FIFOs)
2202 FIFO memory (FIFOm)
2203 FIFO memory (FIFOtp)
2204 Null packet generation unit 2205 TSP switching unit 2206 Transmission buffer 2207 Identification information TSP generation unit 2301 TSP filter processing unit 2302 TSP interval equalization processing unit 2303 Sub-transmission path signal extraction processing unit 4201 Transmission buffer 4202 Transmission block identification information extraction unit

Claims (5)

A stream dividing device that divides an input transport stream (TS) into two transmission lines, a main transmission line and a sub-transmission line,
A stream discriminating unit for identifying the input TS packet (TSP) into a predetermined type and outputting the identification result to the stream structuring unit together with the TSP;
Wherein after storing the TSP inputted from the stream discriminator temporarily memory, using said identification result, and structural information to determine the order of the types of pre-defined TS slot in the transmission block, P CR time stamp Among the TSPs having the TSP, the correction including the reordering of the TSPs and the addition and subtraction of the null packets is performed so that the ratio of the number of TSPs sent on the main transmission line is always constant, and the correction of the PCR time stamp accompanying the correction is performed. A stream structuring unit that performs TS structuring, and
For the TSP of the TS structured by the stream structuring unit, according to the structure information, the TSP (TYPE_m) transmitted on the main transmission path without the PCR time stamp and the main transmission regardless of the presence or absence of the PCR time stamp The TSP (TYPE_t) transmitted on the path and the TSP (TYPE_s) transmitted on the sub-transmission path are separated into three types, and the TSP interval is made uniform for the TSP of the TYPE_m and the TSP of the TYPE_t. A stream demultiplexer that outputs the transmission block identification information for identifying the transmission block and the TSP of the TYPE_s for the transmission line, and outputs the transmission block identification information for the sub-transmission path;
A stream dividing apparatus comprising:   The stream separation unit further includes means for outputting a PCR time stamp value of a TSP having a PCR time stamp in the transmission block and position information indicating a position of a TS slot in the transmission block. Item 2. The stream dividing device according to Item 1. A receiving apparatus that receives a TSP that is divided into two transport paths, a main transmission path and a sub-transmission path, and reconfigures the transport stream (TS) into the one TS,
The one TS has a TSP (TYPE_m) transmitted on the main transmission path without a PCR time stamp, a TSP (TYPE_t) transmitted on the main transmission path regardless of the presence or absence of the PCR time stamp, and a sub-transmission. The TSP (TYPE_s) transmitted on the path is separated into three types, the TSP of the TYPE_m and the TSP of the TYPE_t are equalized at the TSP interval and transmitted on the main transmission path, and transmitted with the TSP of the TYPE_s. It is specified that the identification information of the transmission block for identifying the block is transmitted on the sub transmission path,
After the TSP is temporarily stored in the memory, the one TS includes an identification result for identifying the TSP in a predetermined type and structure information for determining the order of the types of TS slots defined in the transmission block. The correction including the reordering of the TSP and the addition and removal of null packets is performed so that the ratio of the number of TSPs sent on the main transmission line is always constant, and the PCR time stamp is corrected according to the correction. And
A main signal receiver for receiving a TSP transmitted on the main transmission path;
And Fuchsin No. reception section that receives identification information of the transmission blocks for identifying the transmitted TSP and transmission blocks sub-transmission line,
When the TSP received via the main transmission path is stored in the TS slot of TYPE_t and the TS slot of TYPE_m according to the structure information, and the type of TS slot when storing the TSP including the PCR time stamp is not TYPE_t The stream composition unit which modifies the arrangement of the transmission block so that the TS slot at the TSP storage position becomes TYPE_t, and sequentially stores the TSP received via the sub-transmission path in the TS slot of the TYPE_s of the transmission block And
When the stream synthesis unit determines that the transmission block delimiter of the TSP received from the sub-transmission path is reached before all the TYPE_s TS slots of the transmission block are stored according to the identification information of the transmission block. A receiver characterized in that a null packet is stored in a TS slot of TYPE_s thereafter in the transmission block, and the one TS is combined. The stream synthesis unit
Means for extracting identification information of the transmission block for the TSP received from the main transmission path and storing it in a predetermined transmission buffer for each transmission block;
Means for receiving and extracting transmission block identification information from the sub-transmission path, and storing the TSP received from the sub-transmission path in a transmission block storage area that matches the transmission block identification information in the transmission buffer;
The receiving apparatus according to claim 3, comprising: The stream synthesis unit
Means for extracting the value of the PCR time stamp of the TSP having the PCR time stamp in the transmission block obtained from the sub-transmission path and the position information of the TS slot in the transmission block defined in advance by the transmission side;
It is determined whether or not the TSP received from the main transmission path has the same value as the PCR timestamp value input from the sub transmission path. If it is determined that the TSP has the same value, the TS slot for storing the TSP is determined. Means for modifying the arrangement of the transmission block so as to match the position information of the TS slot in the transmission block;
The receiving apparatus according to claim 3, wherein the receiving apparatus includes:

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