JP5119550B2 - Data processing system and data processing method - Google Patents

Description

  The present invention relates to a data processing system and a data processing method, and more particularly to a data processing system and a data processing method in a decoder compliant with the MPEG-2 standard.

  MPEG-2 TS (Transport Stream) includes a PES (Packetized Elementary Stream) for transmitting video data, a PES for transmitting audio data, and a PES for transmitting other data. In the MPEG-2 system decoder, first, a plurality of PESs included in a TS are separated according to the type of data to be transmitted. Next, each PES is separated into a header and a payload. The header includes time information such as PTS (Presentation Time Stamp: presentation time information) or DTS (Decoding Time Stamp: decoding time information). The payload includes an ES (Elementary Stream). The ES is, for example, encoded video data or audio data. The MPEG-2 system decoder includes a video decoder, an audio decoder, and the like. These decoders perform presentation or decoding of an ES based on time information included in the header.

  FIG. 12 is a block diagram showing the configuration of the MPEG-2 video decoder 100. As shown in FIG. 12, the video decoder 100 includes a PES decoding unit 101, buffers 102 and 103, a determination circuit 104, and an ES decoding unit 105.

  The PES decoding unit 101 separates PES input from the outside into a header and a payload. The payload is stored in the buffer 102 and the header is stored in the buffer 103. In the buffer 102 and the buffer 103, a plurality of payloads and a plurality of headers corresponding to a plurality of continuously input PESs are stored, respectively. The determination circuit 104 determines whether or not there is a payload including a sequence header (hereinafter referred to as “specific payload”) among the plurality of payloads stored in the buffer 102. When the specific payload exists, the determination circuit 104 reads time information (hereinafter referred to as “specific time information”) in the header corresponding to the specific payload from the buffer 103, and based on the specific time information. The ES decoding process is executed.

  A technique related to the MPEG-2 decoder is disclosed in, for example, Patent Document 1 below.

JP 2003-244644 A

  According to the video decoder 100 shown in FIG. 12, since the functions of the video decoder are all constructed as hardware, the circuit scale increases.

  The present invention has been made in view of such circumstances, and a data processing system and data processing capable of reducing the circuit scale of a decoder by realizing a decoding function in cooperation with hardware and software. The purpose is to obtain a method.

  A data processing system according to a first aspect of the present invention includes a processing device, a first processing unit that processes PES (Packetized Elementary Stream), a second processing unit that processes ES (Elementary Stream), and the first processing unit. A first storage unit accessible by the processing unit and the second processing unit; and a second storage unit accessible by the processing device, wherein the first processing unit includes a plurality of PESs Are stored in the first storage unit, the second storage unit stores time information in each header of a plurality of PESs, and the second processing unit stores the first storage unit in the first storage unit. Searching for a specific payload including specific information indicating a start point of a sequence from a plurality of payloads stored in the unit, and the processing device stores a plurality of times stored in the second storage unit From the information, the specific pay Searching a specific time information corresponding to the second processing unit executes the process of ES on the basis of the specific time information.

  A data processing system according to a second invention is the data processing system according to the first invention, in particular, a third storage unit accessible by the first processing unit and the processing device, and the second processing. And a fourth storage unit accessible by the processing device, wherein the first processing unit stores a storage address of each of a plurality of payloads in the third storage unit, and the second storage unit The processing unit stores the storage address of the specific payload in the fourth storage unit, and the processing device stores a plurality of storage addresses stored in the third storage unit and the fourth storage. The specific time information is searched based on the storage address stored in the section.

  In the data processing system according to the third invention, in particular in the data processing system according to the second invention, the storage address of each payload corresponding to each header is stored in each of the second storage units in each time information. It is characterized by being stored in association with.

  In the data processing system according to the fourth invention, particularly in the data processing system according to the second or third invention, the specific information indicating the start point of the sequence is a sequence header, and is stored in the fourth storage unit. The storage address to be stored is a head address in which a picture header following the sequence header is stored.

  A data processing system according to a fifth invention is characterized in that, in the data processing system according to any one of the first to fourth inventions, the processing device is a CPU.

  According to a sixth aspect of the present invention, there is provided a data processing method comprising: (A) a step of separating a PES (Packetized Elementary Stream) into a header and a payload; and (B) storing each payload of the plurality of PESs in a first storage unit. (C) storing time information in each header of the plurality of PESs in the second storage unit; and (D) among the plurality of payloads stored in the first storage unit. And (E) searching for a specific payload including specific information indicating the start point of the sequence, and (E) corresponding to the specific payload from a plurality of time information stored in the second storage unit Searching for specific time information to perform, and (F) performing an ES (Elementary Stream) process based on the specific time information.

  A data processing method according to a seventh invention is the data processing method according to the sixth invention, in particular, (G) storing each storage address of a plurality of payloads in a third storage unit; Storing a storage address of a specific payload in a fourth storage unit, and in the step (E), a plurality of storage addresses stored in the third storage unit, and the fourth storage unit The specific time information is searched based on a storage address stored in a storage unit.

  In the data processing method according to the eighth invention, particularly in the data processing method according to the seventh invention, in the step (C), the storage address of each payload corresponding to each header is included in each time information. It is stored in the second storage unit in association with each other.

  The data processing method according to the ninth invention is the data processing method according to the seventh or eighth invention, in particular, the specific information indicating the start point of the sequence is a sequence header, and in the step (H), The storage address stored in the fourth storage unit is a head address in which a picture header following the sequence header is stored.

  According to the data processing system according to the first to fifth inventions, the software processing by the processing device and the hardware functions by the first and second processing units and the first and second storage units, PES and ES decoding functions can be realized. Therefore, the circuit scale of the decoder device can be reduced as compared with the case where all functions are constructed by hardware.

  In particular, according to the data processing system of the second invention, the third and fourth storage units accessible by the processing device are provided, and each storage address of the plurality of payloads is stored in the third storage unit. And the storage address of the specific payload is stored in the fourth storage unit. Accordingly, referring to the third and fourth storage units makes it easy to compare the storage addresses by the processing device.

  In particular, according to the data processing system of the third invention, the storage address of each payload corresponding to each header is stored in the second storage unit in association with each time information. Therefore, the processing device can easily and reliably read out the specific time information corresponding to the specific payload from the second storage unit by notifying the storage address of the specific payload to the second storage unit. It becomes.

  In particular, according to the data processing system of the fourth aspect of the present invention, the fourth storage unit stores the start address where the picture header following the sequence header is stored as the storage address of the specific payload. Therefore, the second processing unit can appropriately start the decoding process of the picture header following the sequence header by starting the ES process from the storage address stored in the fourth storage unit. .

  According to the data processing methods of the sixth to ninth inventions, step (E) can be executed by software processing, and all or part of the other steps (A) to (D), (F) It can be executed by a hardware function. Accordingly, the PES and ES decoding functions can be realized by the cooperation of the software processing and the hardware functions. Therefore, the circuit scale of the decoder device can be reduced as compared with the case where all functions are constructed by hardware.

  In particular, according to the data processing method of the seventh invention, the third and fourth storage units accessible by the processing device are provided, and each storage address of the plurality of payloads is stored in the third storage unit. And the storage address of the specific payload is stored in the fourth storage unit. Accordingly, referring to the third and fourth storage units makes it easy to compare the storage addresses by the processing device.

  In particular, according to the data processing method of the eighth invention, the storage address of each payload corresponding to each header is stored in the second storage unit in association with each time information. Therefore, the processing device can easily and reliably read out the specific time information corresponding to the specific payload from the second storage unit by notifying the storage address of the specific payload to the second storage unit. It becomes.

  In particular, according to the data processing method of the ninth invention, the fourth storage unit stores the start address in which the picture header following the sequence header is stored as the storage address of the specific payload. Accordingly, in step (F), it is possible to appropriately start the decoding process of the picture header following the sequence header by starting the ES process from the storage address stored in the fourth storage unit. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the element which attached | subjected the same code | symbol in different drawing shall show the same or corresponding element.

  FIG. 1 is a block diagram showing a configuration of a data processing system 1 according to an embodiment of the present invention. The data processing system 1 according to the present embodiment can be applied to a video decoder in an MPEG-2 system decoder, for example. However, the application target of the present invention is not limited to this. As shown in FIG. 1, a data processing system 1 according to the present embodiment includes a PES (Packetized Elementary Stream) decoder 2, an ES (Elementary Stream) decoder 3, a storage device 4, and a CPU 5. The CPU 5 is connected to the storage device 4 and the ES decoder 3 via a bus (not shown).

  The storage device 4 includes a buffer 6, a buffer 7, a register 8, and a register 9. For example, it is possible to allocate a part of the DRAM memory space as the buffer 6 and the other part as the buffer 7. The buffers 6 and 7 each function as a ring buffer having a predetermined storage capacity.

  In the example shown in FIG. 1, the buffer 6 is accessible by the PES decoder 2 and the CPU 5, and the buffer 7 is accessible by the PES decoder 2 and the ES decoder 3. The register 8 can be accessed by the PES decoder 2 and the CPU 5, and the register 9 can be accessed by the ES decoder 3 and the CPU 5.

  FIG. 2 is a flowchart showing the flow of processing in the PES decoder 2. FIG. 3 is a flowchart showing the flow of processing in the ES decoder 3. FIG. 4 is a flowchart showing the flow of processing in the CPU 5. Hereinafter, the operation of the data processing system 1 according to the present embodiment will be described with reference to FIGS.

  First, in step SP101 of FIG. 2, the PES decoder 2 separates the PES sent as data S1 from the preceding processing apparatus into a header H and a payload P. Here, when the data processing system 1 is applied to a video decoder in an MPEG-2 system decoder, the above-mentioned processing device is a PES that transmits MPEG-2 TS (Transport Stream) and transmits video data. And a demultiplexer for separating the PES for transmitting audio data and the PES for transmitting other data.

  FIG. 5 is a diagram showing the structure of the PES. The PES has a header H and a payload P. The header includes time information T such as PTS (Presentation Time Stamp: presentation time information) or DTS (Decoding Time Stamp: decoding time information). The payload P includes ES. When the data processing system 1 is applied to a video decoder in an MPEG-2 system decoder, the ES is, for example, encoded video data. Or the sequence header which is a header which shows the starting point of a sequence may be contained in the payload P as ES. In such a PES, a picture header of an I picture (Intra-Picture) exists after the sequence header.

  Next, in step SP102 of FIG. 2, the PES decoder 2 extracts time information T from the header H separated in step SP101.

  Next, in step SP103 of FIG. 2, the PES decoder 2 transmits the payload P separated in step SP101 to the buffer 7 as data S2, and stores the payload P in the buffer 7. Step SP103 may be executed before step SP102, or may be executed in parallel with step SP102.

  FIG. 6 is a diagram illustrating an example of the buffer 7. In the example illustrated in FIG. 6, the buffer 7 stores a total of eight payloads P, ie, payloads P1 to P8. In the following description, it is assumed that the payload P1 is the oldest and the payload P8 is the newest. Payloads P1 to P8 are stored in the buffer 7 with consecutive addresses. For example, the payload P1 is stored from the address “100” to the address “199”, and the subsequent payload P2 is stored from the address “200” continuous to the address “199” to the address “299”.

  Next, in step SP104 of FIG. 2, the PES decoder 2 transmits the time information T extracted in step SP102 and the storage address A of the payload P stored in the buffer 7 in step SP103 to the buffer 6 as data S3. The time information T and the storage address A are associated with each other and stored in the buffer 6. For example, the final address of the buffer 7 storing the current payload P and the final address of the buffer 7 storing the previous payload P are set as the storage address A.

  FIG. 7 is a diagram showing an example of the buffer 6 corresponding to FIG. As an example, when the payload P4 shown in FIG. 6 is the payload P stored in the current buffer 7, it is time information T4 corresponding to the current payload P4 and the last address of the buffer 7 storing the current payload P4. The address “499” and the address “399” which is the final address of the buffer 7 storing the previous payload P3 are stored in the buffer 6. As another example, when the payload P8 shown in FIG. 6 is the payload P stored in the current buffer 7, the time information T8 corresponding to the current payload P8 and the final address of the buffer 7 storing the current payload P8 are shown. “899” address and “799” address which is the last address of the buffer 7 storing the previous payload P7 are stored in the buffer 6.

  Next, in step SP105 of FIG. 2, the PES decoder 2 transmits the storage address A stored in the buffer 6 in step SP104 to the register 8 as data S4, and stores the storage address A in the register 8. Step SP105 may be executed before step SP104, or may be executed in parallel with step SP104.

  FIG. 8 is a diagram showing an example of the register 8 corresponding to FIGS. Data relating to only the storage address A obtained by deleting the time information T1 to T8 from the stored data in the buffer 6 shown in FIG. For example, “299,399” which is the storage address A of the third row of the register 8 is the same as “299,399” which is the storage address A in the storage data of the third row of the buffer 6, and the register “699,799” which is the storage address A of the seventh row of 8 is the same as “699,799” which is the storage address A in the storage data of the seventh row of the buffer 6.

  Next, in step SP201 in FIG. 3, the ES decoder 3 searches for the payload P including the sequence header from the plurality of payloads P1 to P8 stored in the buffer 7. The sequence header is a header indicating the start point of the sequence, and is given a unique ID number. The ES decoder 3 searches for the payload P including the sequence header by searching for the unique ID number in the buffer 7.

  Next, in step SP202 of FIG. 3, the ES decoder 3 determines whether or not the payload P including the sequence header has been found, and if not found (that is, if the result of the determination in step SP202 is “NO”). Returns to step SP201.

  On the other hand, if the payload P including the sequence header is found (that is, if the result of determination in step SP202 is “YES”), then in step SP203 of FIG. 3, the ES decoder 3 includes the sequence header. From the payload P, the picture header of the I picture following the sequence header is specified. Next, the ES decoder 3 determines the storage address in the buffer 7 in which the picture header is stored. Next, the ES decoder 3 transmits the storage address B, which is the head address of the storage address, to the register 9 as data S5, and stores the storage address B in the register 9.

  FIG. 9 is a diagram illustrating an example of the register 9. FIG. 9 shows an example in which the payload P including the sequence header is the payload P3 shown in FIG. 6 and the storage address B of the picture header of the I picture is “350”.

  Next, in step SP204 in FIG. 3, the ES decoder 3 notifies the CPU 5 as data S6 that the storage address B has been stored in the register 9.

  Next, in step SP301 shown in FIG. 4, the CPU 5 refers to the registers 8 and 9 and changes the storage address A stored in the register 9 from the plurality of storage addresses A stored in the register 8. Search for the corresponding storage address. Specifically, the CPU 5 searches for the storage address A in which two storage addresses sandwiching the storage address B are defined. In this example, since storage address B is “350”, storage address A (storage address in the third row of register 8) in which two storage addresses “299, 399” sandwiching “350” are defined. Is specified as the storage address A corresponding to the storage address B.

  Next, in step SP302 shown in FIG. 4, the CPU 5 transmits the storage address A specified in step SP301 to the buffer 6 as data S7. In this example, the storage address A “299, 399” is transmitted from the CPU 5 to the buffer 6.

  Next, in step SP303 shown in FIG. 4, the time information T corresponding to the storage address A received from the CPU 5 is read from the buffer 6, and the time information T is transmitted to the CPU 5 as data S8. S8 is received. In this example, time information T 3 corresponding to the storage address A “299, 399” is transmitted from the buffer 6 to the CPU 5.

  Next, in step SP304 shown in FIG. 4, the CPU 5 transmits the time information T received from the buffer 6 in step SP303 to the ES decoder 3 as data S9. In this example, the CPU 5 transmits time information T3 to the ES decoder 3.

  Next, in step SP205 shown in FIG. 3, the ES decoder 3 receives the time information T transmitted from the CPU 5 in step SP304. In this example, the ES decoder 3 receives time information T3 transmitted from the CPU 5.

  Next, in step SP206 shown in FIG. 3, the ES decoder 3 executes ES decoding processing based on the time information T (time information T3 in this example) received in step SP205. Here, the ES decoder 3 can appropriately execute the decoding process from the picture header of the I picture by starting the decoding process from the storage address B stored in the register 9.

  As described above, according to the data processing system 1 according to the present embodiment, the software processing by the CPU 5 and the hardware functions by the PES decoder 2, ES decoder 3, buffers 6 and 7, and registers 8 and 9 are cooperated. , PES and ES decoding functions can be realized. Therefore, the circuit scale of the decoder device can be reduced as compared with the case where all functions are constructed by hardware.

  Also, registers 8 and 9 accessible by the CPU 5 are provided. The register 8 stores the storage addresses A of the plurality of payloads P1 to P8. The register 9 stores the payload P3 including the sequence header. A storage address B is stored. Therefore, by referring to the registers 8 and 9, the CPU 5 can easily compare the storage addresses A and B.

  In the buffer 6, the storage address A of each payload P corresponding to each header H is stored in association with each time information T. Therefore, the CPU 5 notifies the buffer 6 of the storage address A (“299, 399”) of the payload P3 including the sequence header to the buffer 6 so that the time information T3 corresponding to the payload P3 including the sequence header can be simply and from the buffer 6. It is possible to read the data reliably.

  Moreover, the buffer 6 does not store the header H itself, but stores time information T extracted from the header H and a storage address A associated with the time information T. Therefore, when searching for the time information T3 corresponding to the payload P3 including the sequence header in the buffer 6, the load of the search process is reduced, so that the time required for the search can be shortened.

  In the register 9, the head address where the picture header of the I picture following the sequence header is stored is stored as the storage address B. Therefore, the ES decoder 3 can appropriately start the decoding process of the picture header of the I picture following the sequence header by starting the decoding process of the ES from the storage address B stored in the register 9. .

  Furthermore, since the CPU 5 can access the buffer 6, debugging work by software processing using the CPU 5 becomes easier as compared with the configuration in which the CPU cannot access the buffer 103 as shown in FIG. 12.

  Further, indirect data communication is performed between the PES decoder 2 and the ES decoder 3 via the storage device 4 and the CPU 5, and direct data communication from the PES decoder 2 to the ES decoder 3 is not performed. Therefore, even if the IP of the PES decoder 2 and the IP of the ES decoder 3 are different from each other, communication between the two can be realized by software processing.

  Hereinafter, modifications of the present embodiment will be described.

  FIG. 10 is a block diagram showing a first modification. In the example shown in FIG. 1, both the time information T and the storage address A are stored in the buffer 6 by the PES decoder 2. On the other hand, in the first modification shown in FIG. 10, the PES decoder 2 stores only the time information T as data S3T in the buffer 6, and the storage address A refers to the register 8 so that the CPU 5 To store.

  FIG. 11 is a block diagram showing a second modification. In the example shown in FIG. 11, the buffer 6 can be accessed only by the CPU 5. In the example shown in FIG. 1, the time information T and the storage address A are stored in the buffer 6 by the PES decoder 2. On the other hand, in the second modification shown in FIG. 11, the PES decoder 2 stores the time information T and the storage address A in the register 8, and by referring to the register 8, the CPU 5 stores the time information T and the storage address A. Address A is stored in buffer 6.

  Also by the first and second modifications shown in FIGS. 10 and 11, the same effects as those of the above embodiment can be obtained.

It is a block diagram which shows the structure of the data processing system which concerns on embodiment of this invention. It is a flowchart which shows the flow of the process in a PES decoder. It is a flowchart which shows the flow of the process in ES decoder. It is a flowchart which shows the flow of the process in CPU. It is a figure which shows the structure of PES. It is a figure which shows an example of a buffer. It is a figure which shows an example of a buffer corresponding to FIG. It is a figure which shows an example of a register corresponding to FIG. It is a figure which shows an example of a register | resistor. It is a block diagram which shows a 1st modification. It is a block diagram which shows the 2nd modification. It is a block diagram which shows the structure of a video decoder.

Explanation of symbols

1 Data Processing System 2 PES Decoder 3 ES Decoder 4 Storage Device 5 CPU
6,7 buffer 8,9 registers

Claims (9)

A processing device;
A first processing unit that processes a PES (Packetized Elementary Stream);
A second processing unit for processing an ES (Elementary Stream);
A first storage unit accessible by the first processing unit and the second processing unit;
A second storage unit accessible by the processing device,
The first processing unit stores the payload of each of a plurality of PESs in the first storage unit,
The second storage unit stores time information in each header of the plurality of PESs,
The second processing unit searches for a specific payload including specific information indicating a start point of a sequence from a plurality of payloads stored in the first storage unit,
The processing device searches for specific time information corresponding to the specific payload from a plurality of time information stored in the second storage unit,
The data processing system, wherein the second processing unit executes ES processing based on the specific time information. A third storage unit accessible by the first processing unit and the processing device;
A fourth storage unit accessible by the second processing unit and the processing device;
The first processing unit stores a storage address of each of a plurality of payloads in the third storage unit,
The second processing unit stores a storage address of the specific payload in the fourth storage unit,
The processing device searches for the specific time information based on a plurality of storage addresses stored in the third storage unit and a storage address stored in the fourth storage unit. Item 4. The data processing system according to Item 1.   The data processing system according to claim 2, wherein a storage address of each payload corresponding to each header is stored in the second storage unit in association with each time information. The specific information indicating the starting point of the sequence is a sequence header,
4. The data processing system according to claim 2, wherein the storage address stored in the fourth storage unit is a head address in which a picture header following the sequence header is stored. 5.   The data processing system according to claim 1, wherein the processing device is a CPU. (A) separating a PES (Packetized Elementary Stream) into a header and a payload;
(B) storing the payload of each of the plurality of PESs in the first storage unit;
(C) storing time information in each header of the plurality of PESs in the second storage unit;
(D) searching for a specific payload including specific information indicating a start point of a sequence from a plurality of payloads stored in the first storage unit;
(E) searching for specific time information corresponding to the specific payload from a plurality of time information stored in the second storage unit;
(F) A data processing method comprising: executing an ES (Elementary Stream) process based on the specific time information. (G) storing a storage address of each of the plurality of payloads in the third storage unit;
(H) storing the storage address of the specific payload in a fourth storage unit,
In the step (E), the specific time information is searched based on a plurality of storage addresses stored in the third storage unit and a storage address stored in the fourth storage unit. The data processing method according to claim 6.   8. The data processing method according to claim 7, wherein in step (C), the storage address of each payload corresponding to each header is stored in the second storage unit in association with each time information. . The specific information indicating the starting point of the sequence is a sequence header,
9. The data processing method according to claim 7, wherein the storage address stored in the fourth storage unit in the step (H) is a head address in which a picture header following the sequence header is stored.

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