JP2001052448A - Medium and device for data recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an encoded data stream which can easily be analyzed by inserting stuffing data into a data block of packets which has part of a predetermined control code present a length, determined by a certain rule, behind the head of a connection stream and includes the connection stream. SOLUTION: An input stream 1-1 is divided into divided streams 1-4, 1-5, 1-6, 1-7, and 1-8. At this time, the stream is so divided that control codes 1-2 and 1-3 are not divided. When the divided streams are made constant in length and their division positions are determined, the control codes are possibly divided. When a division position is on a control code, the division position is set before the control code. Stuffing data 1-9 are inserted into the divided streams when necessary, and headers 1-10, 1-11, 1-12, 1-13, and 1-14 are added as data blocks to generate packets 1-15, 1-16, 1-17, 1-18, and 1-19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording medium for packetizing and recording a stream, a computer-readable recording medium for recording a data packetizing method, and a data recording apparatus, and more particularly, to multimedia data such as MPEG. The present invention relates to a data recording medium, a computer-readable recording medium recording a data packetizing method, and a data recording apparatus.

[0002]

2. Description of the Related Art MPEG (Moving) is a technique for recording and transmitting a large amount of video and audio information as digital data.
Picture Experts Group) and other encoding schemes have been formulated, and the ISO / IEC11172 standard and ISO / I
It is an international standard encoding system as the EC13818 standard. These systems have been adopted as encoding systems for digital satellite broadcasting, DVDs, and the like, and their use is becoming more and more popular at present.

In addition, the development of digital video cameras, DV
With the advent of large-capacity recording media such as D-RAM and DVD-RW, the demand for processing of digitally recorded video and audio has been increasing, and R & D for high-speed retrieval and analysis of such data has been actively conducted. Is being done.

[0004] Hereinafter, the MPEG system will be described as an example. ISO / IEC 13818 standard (hereinafter MP
EG-2 standard) is based on the ISO / IEC13818-1 standard (hereinafter referred to as system standard) and ISO / IEC13818-
2 standards (hereinafter video standards), ISO / IEC1381
It is composed of 8-3 standards (hereinafter referred to as audio standards) and the like, and has a configuration in which streams of video standards and audio standards are multiplexed according to system standards. In the video standard and the audio standard, video and audio information are structured according to coding units, and the information is detected based on a specific start code and synchronization data. In the system standard, not only video and audio information but also information such as encoder parameters and data arrangement in storage media can be multiplexed.

When these data streams are multiplexed for transmission and recording, the streams conforming to the video standard and the audio standard are divided into appropriate lengths according to the system standard and packetized by adding a header. Multiplexing is performed in packet units. The packet includes a header portion and a payload portion, and information for synchronizing video and audio, a flag indicating a characteristic of data, and the like are recorded in the header portion. Video and audio data streams are recorded in the payload section.

[0006] By dividing a stream into packets of a fixed length and multiplexing the data, data can be recorded, transmitted and reproduced efficiently. In particular, when a storage medium such as a DVD or a CD is used, the length of a sector, which is a unit of recording, is determined, and the journal of the Institute of Image Information and Television Vol. 51 No. 7 pp. 942-94
6 (1997), DVDs are determined to record data in units of packs having a length of 2048 bytes. Also, as indicated in the MPEG-2 system standard, fixed-length TS packets are used in transport streams (TS) used for satellite broadcasting and the like.

[0007]

[0005] While streaming can be efficiently multiplexed by packetization, when a stream is divided into a certain length and packetized,
In some cases, a start code or a synchronization data string included in a video or audio stream is divided into a plurality of packets and recorded. In this case, the start code of the stream cannot be detected only by checking the payload portion of the packet individually, and a problem occurs in that the detection and analysis methods become complicated and the processing time increases.

As an example of packetization so that the packet length is constant, there is a case where data is recorded on a DVD. In the case of a DVD, data is recorded in units of 2048 bytes as described above. A fixed-length TS packet is also used when packetizing a transport stream specified in the MPEG-2 system standard. Each of the pack and the TS packet is composed of a header portion and a data block portion, and a control code such as a start code included in the data block portion may be divided into a plurality of packs or packets.

FIG. 2 shows an example. A method of packetizing the packet so that the packet length is constant is used as an example. The input stream (2-1) is divided and divided streams (2-4, 2-5, 2-6, 2-7, 2-8)
After that, the above divided stream is used as a data block as a header (2-11, 12-2, 2-13, 2-14,
2-15) and the packet (2-16, 2-17,
2-18, 2-19, 2-20). If the length of the header is constant, the length of the packet can be constant if the length of the divided stream is constant. However, at this time, the predetermined control code (2-3 in this case) included in the stream is divided and the divided control code (2-
9, 2-10), and the control code may not be detected in packet units. For example, assuming that the control code included in the stream is a sequence header (0x000001B3) in the MPEG-2 standard and is divided at the center of the code, the first half 0x
0000 is included in the data block of the previous packet, and the latter half 0x01B3 is included in the data block of the subsequent packet, so that the control code is divided. Can not.

As another problem, as described in the MPEG-2 system standard, a boundary between a header portion and a payload portion added based on the system standard at the time of packetization is defined by a video standard or the like. The same data series as the determined start code may occur. This data sequence is called a pseudo start code. The pseudo start code causes erroneous detection when detecting the start code from the packetized data sequence.

FIG. 3 shows an example. In the figure, a method of packetizing a packet so that the length of the packet is constant is used as an example. The input stream (3-1) is divided into divided streams (3-5, 3-6, 3-7, 3-
8, 3-9), and the above divided stream is used as a data block as a header (3-11, 3-12, 3-1).
3, 3-14, 3-15) and the packet (3-1).
6, 3-17, 3-18, 3-19, 3-20). A predetermined control code (3
-2, 3-3) and the like.

Assuming that the length of the header is constant, the length of the packet can be constant if the length of the divided stream is constant. However, at this time, if a specific data string (3-4) exists in the stream, the added header (3-1)
By combining with a part of 4), the same data sequence (3-10) as a predetermined control code is generated,
This may cause false detection of control codes.

For example, when a stream conforming to the MPEG-2 video standard is packetized in accordance with the MPEG-2 system standard, if a specific data sequence (0x000001) exists at the end of a data block, the header of the next packet header In combination with the data sequence (0x000001E0), a picture start code (0x00000100) in the MPEG-2 video standard, which should be detected only in the data block, appears at the boundary of the packet. Change the length of the data block,
By creating data blocks in picture units, it is possible to suppress the occurrence of pseudo start codes,
This technique cannot be used when the packet length is fixed.

[0014] In the conventional packetization processing conforming to the MPEG-2 standard or the like, since the main purpose is to multiplex a stream, the contents of the data in the payload portion have not been checked in advance. For this reason, the above-described problem has occurred. However, in order to analyze and edit the stream after packetization by an easy means, it is desirable to create packetized data without a control code or a pseudo start code divided in advance.

[0015] Accordingly, an object of the present invention is to estimate in advance the problems caused by the packetization method, such as when a control code such as a stream start code is divided into a plurality of packets by packetization or when a pseudo start code is generated. An object of the present invention is to provide a coded data sequence which is easy to analyze by packetizing so as not to cause these phenomena, and a data packetizing method and a data packetizing device for creating the same.

[0016]

According to the present invention, in order to solve the above-mentioned problems, a data recording medium on which a stream is recorded is composed of a data block including an input stream and having a fixed length according to a certain rule, and a header. Data recording medium on which the packet to be recorded is recorded,
Regarding a stream in which an input stream included in a data block of an arbitrary packet and an input stream included in a subsequent packet are concatenated, the stream is previously set at a position behind the head of the concatenated stream by a length determined by the certain rule. A data recording medium in which a part of a predetermined control code exists and stuffing data is inserted in a data block of the packet is used.

The data recording medium on which the stream is recorded is a data recording medium on which a packet including an input stream and having a data block whose length is determined according to a certain rule and a header is recorded. And a stream obtained by concatenating the input stream included in the data block of the packet with the input stream included in the subsequent packet, exists at a position behind the head of the concatenated stream by the length determined by the certain rule. A data recording medium in which a data sequence is a data sequence that becomes the same data sequence as a predetermined control code by being combined with a part of a header of a packet, and stuffing data is inserted in a data block of the packet. Is used.

The fixed rule is a rule for making the length of the data block of each packet or the length of each packet constant for each type of packet or for all packets.

Here, the predetermined control code is a start code or synchronous data indicating an information start position in a stream, an end code indicating an information end position in a stream, and a data string accompanying these.

The stream is divided into a plurality of data blocks, and a header is added to each data block to form a packet. The data packetizing method is recorded as a computer-readable recording medium on the basis of a predetermined packetizing method. A first step of packetizing the stream by the first step; a second step of determining whether a predetermined control code included in the stream is divided into a plurality of packets by the first step; A third step of creating a data block in which the control code is completed in the data block based on the determination result; and a fourth step of packetizing the data block based on the predetermined packetization method. Readable recording medium on which a data packetizing method is recorded Used.

The stream is divided into a plurality of data blocks, and a header is added to each data block to form a packet. The data packetizing method is recorded as a computer-readable recording medium based on a predetermined packetizing method. And a data sequence consisting of a part of the data in the stream and a part of the added header in the fifth step of packetizing the stream by the fifth step. A sixth step of determining whether or not the data packet will be the same, a seventh step of creating a data block that does not generate the same data series based on the determination result, and a step of converting the data block into the predetermined packetization method. Compiling a data packetizing method comprising an eighth step of packetizing based on Used over data readable recording medium.

The predetermined packetization method is as follows:
A method of packetizing the data block length or the packet length so as to be constant, a method of dividing a stream according to a fixed time interval and packetizing the data, or a method of combining these.

The method for determining whether or not a predetermined control code included in the stream is divided into a plurality of packets includes the step of dividing the stream by the predetermined packetizing method. This is a method of determining by checking whether or not a predetermined control code exists at a division position of a stream divided by the method.

[0024] In the method of creating a data block in which the control code is completed in the data block, the predetermined control code is determined to be divided by a plurality of packets. If the stream is divided by changing the stream division position to the position before or after the control code, the stuffing data is inserted, a data block is created, and it is determined that the data block is not divided. Is a method of creating a data block according to the predetermined packetization method.

The method for judging whether or not a data sequence composed of a part of the data in the stream and a part of the added header becomes the same data sequence as a predetermined control code is performed by the method described above. When the stream is divided by the given packetization method, a data sequence consisting of a part of the data before and after the division position of the stream divided by the division method and a part of the added header is a predetermined control code. This is a method of making a determination based on whether or not the same data series is obtained.

The method of creating a data block that does not generate the same data series is based on the method of determining whether or not the data series is the same. When the position is changed to a position before or after a part of the data in the stream and the stream is divided, stuffing data is inserted to create a data block, and it is determined that the data blocks do not become the same data series. Is a method of creating a data block according to the predetermined packetization method.

The predetermined control code is a start code or synchronous data indicating an information start position in a stream, an end code indicating an information end position in a stream, and a data string accompanying these.

[0028] As a data recording apparatus for dividing a stream into a plurality of data blocks, adding a header to each data block to create and record a packet, the stream is input, and the stream is input based on the predetermined packetization method. Means for outputting a stream division position when dividing the stream, and inputting the division position and the stream, and the predetermined control code included in the stream is divided into a plurality of packets by the predetermined packetization method. Means for outputting a determination result as to whether or not division is performed;
Means for receiving the determination result and the stream as input, outputting the divided position of the stream in which the predetermined control code is completed in the data block, inputting the divided position and the stream, and outputting the divided stream. Means for inputting the divided streams, inserting stuffing data to output a data block, and means for inputting the data block, adding a header, packetizing the packet, and outputting a packet. Use a data recording device.

As a data recording device for dividing a stream into a plurality of data blocks, adding a header to each data block to create and record a packet, the stream is input, and the stream is input based on the predetermined packetization method. Means for outputting a stream splitting position when splitting the stream, and inputting the splitting position and the stream, from a part of data in a data block and a part of a header to be added by the predetermined packetization method. Means for outputting a determination result as to whether or not the data sequence becomes the same data sequence as the predetermined control code, and a stream having the determination result and the input as input, and the same as the predetermined control code. Means for outputting the split position of a stream that does not generate a data sequence, and inputting the split position and the stream Means for outputting the divided stream, means for receiving the divided stream as input, inserting the stuffing data to output a data block, inputting the data block, adding a header, and performing packetization. A data recording device comprising means for outputting a packet is used.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of packetized data created by the present invention, and a method of creating the packetized data will be described.

In the figure, as a packet composed of a data block and a header whose length is determined according to a certain rule, a stream having a constant packet length is used as an example. Data blocks whose lengths are determined according to certain rules will be described later.

First, the input stream (1-1) is divided into divided streams (1-4, 1-5, 1-6, 1-7, 1).
-8). At this time, the control code (1-2, 1-3)
Split the stream so that it does not split If the division position is determined while keeping the length of the division stream constant, the control code may be divided. Therefore, when the division position comes on the control code, the division position is changed before the control code. If necessary, stuffing data (1-9) is inserted into the divided stream, and a header (1-10, 1-11, 1-12, 1-13, 1--1) is inserted as a data block.
14) and the packet (1-15, 1-16, 1-
17, 1-18, 1-19).

For example, as an input stream, MPEG
Video and audio elementary streams (ES) compliant with -2 standard are conceivable. MPEG
When packetization is performed based on the transport stream (TS) described in the -2 system standard, a packetized elementary stream (PES) may be input. Examples of packets include packs, packets, and TS packets in the MPEG-2 standard. For example, the header includes a packet header and a pack header in the MPEG-2 standard.

The content of the MPEG-2 header is ISO / I
As described in the EC 13818 standard.
The stuffing data includes a padding packet. The padding packet is 0x0 according to the MPEG-2 standard.
This packet has a start code of 00001BE. For the contents of the stuffing data and the padding packet, a general technique such as the MPEG-2 system standard can be used as it is. The stuffing data and padding packet may not be present. Thereby, data in which the predetermined control code included in the stream is not divided into a plurality of packets is created.

A stream in which such a control code is not divided into a plurality of packets has the following characteristics on a data recording medium. That is, in the case of a stream having a fixed packet length as exemplified here, when a stream obtained by connecting an input stream included in a certain packet and an input stream included in a subsequent packet is extracted, the connected stream A part of the control code is located at a position behind the head by the length of the data block derived from the length of the packet determined above.

When the input stream is extracted from the packets (1-17) and (1-18), (1-6) and (1-7)
Is connected. The control code (1-3) exists at a position behind the head of this concatenated stream by the length of the data block. Such data structure is obtained by inserting stuffing data to prevent division of the control code. For data in which the control code is not divided into a plurality of packets, the control code can be detected by individually verifying the packets. The predetermined control code will be described later.

FIG. 4 shows another embodiment of the packetized data created by the present invention, and a method of creating the packetized data will be described.

As a packet composed of a data block and a header whose length is determined according to a certain rule, a stream having a constant packet length is used as an example. Data blocks whose lengths are determined according to certain rules will be described later.

First, the input stream (4-1) is divided into divided streams (4-5, 4-6, 4-7, 4-8, 4).
−9). The control code (4-
2, 4-3) and the like. At this time, if there is a specific data sequence (4-4) that becomes the same data sequence as a predetermined control code by combining with a part of the added header, The stream is divided so as not to be a data series. If the division position is determined while keeping the length of the division stream constant, the stream may be divided immediately after the specific data string. In such a case, the division position is changed.

If necessary, stuffing data (4-10) is inserted into the above-mentioned divided stream, and a header (4-11, 4-12, 4-13, 4-1) is inserted as a data block.
4, 4-15) and the packet (4-16, 4-1).
7, 4-18, 4-19, 4-20). The input stream, packet, header, and stuffing data are as described above. As a result, data is created in which a data sequence composed of a part of the data in the stream and a part of the header to be added does not become the same data sequence as a predetermined control code.

A stream that does not have the same data sequence as such a control code has the following characteristics on a data recording medium. That is, in the case of a stream having a fixed packet length as exemplified here, when a stream obtained by connecting an input stream included in a certain packet and an input stream included in a subsequent packet is extracted, the connected stream One part of a specific data sequence that becomes the same data sequence as the control code by combining with a part of the header at a position behind the head by the length of the data block derived from the length of the packet determined above Department exists.

When the input stream is extracted from the packets (4-18) and (4-19), (4-7) and (4-8)
Is connected. A specific data string (4-4) exists at a position behind the head of this concatenated stream by the length of the data block. Such a data structure is obtained by inserting stuffing data and preventing occurrence of the same data series.

Next, a packet composed of a data block and a header whose length is determined according to the above-mentioned certain rules will be described.

FIG. 5 shows an example of the structure of a packet. Generally, the packets (5-1, 5-2) include headers (5-3, 5-4) including information for synchronizing the streams, flags indicating the characteristics of the streams, and data of the streams. It consists of data blocks (5-5, 5-6). The data block may include a packet that is packetized by another method. The header identifies the type of packet.

For example, in the MPEG-2 standard, a video packet has a header starting with 0x000001E0 and the like, and an audio packet has a header starting with 0x000001C0 and the like. The packet and header are as described above. Here, as a packet composed of a data block and a header whose length is determined according to a certain rule, a packet having a constant data block length or a constant packet length can be considered. These rules may be applied to one type of packet, may be applied to a plurality of types, or may be applied to all packets.

As an example in which the length of a packet is constant, see Journal of the Institute of Image Information and Television Engineers, Vol. 51 No. 7
pp. 942-946 (1997),
In DVD, it is determined that data is recorded in units of 2048 bytes in length. In a transport stream (TS) of the MPEG-2 system standard used for satellite broadcasting or the like, a fixed-length TS packet is used.

Next, the predetermined control code will be described.

FIG. 6 shows an example of the configuration of a packet and a control code. The packet (6-1) includes a header (6-2) and a data block (6-3). A data block is constituted by a stream. The control code (6-4) exists in the stream. The control code includes a start code indicating the information start position in the stream, or synchronous data and an end code indicating the information end position in the stream (6-5), and a data string (6-6) associated therewith.
Consists of For example, in the MPEG-2 standard, a sequence header, a picture header, a header of an audio access unit, an audio frame, audio sample data, and the like are control codes. The sequence header starts with a sequence start code (0x000001B3) and has an accompanying data string such as bit rate information.
The picture header is a picture start code (0x000)
00100), and has an accompanying data string such as a picture type. The header of the audio access unit starts with synchronous data (0xFFF) and has an accompanying data string such as a layer. There may be no accompanying data. The length of the control code may be adjusted to the length of the data to be detected in packet units. Regarding control codes in the MPEG-2 standard, ISO / IEC 1381
8 as described in the Standard.

FIG. 7 shows an embodiment of a system configuration for realizing a data packetizing method using a computer-readable data recording medium used in the present invention. The computer (7-1) reads the computer-readable recording medium (7-2) and loads the program into the memory, whereby the computer operates to realize data packetization. 4 shows the internal configuration (7-3) of the computer. The program is loaded into the program memory (7-5). The arithmetic unit (7-4) reads this program, packetizes the input stream taken into the input buffer (7-6) according to the instruction, and converts the packet into an output buffer (7-
7) and output the packetized data from the output buffer. These memories are only functionally classified and may be on the same memory.

FIG. 8 shows an embodiment of a method of packetizing data recorded on a computer-readable data recording medium according to the present invention, and the method will be described.

In the figure, the operation is first started from step (8-1), and in step (8-2), the position at which the input stream is to be divided into streams based on a predetermined packetization method is determined. , Step (8-
Proceed to 3). The input stream is as described above. The predetermined packetization method will be described later.

In step (8-3), step (8-
It is determined whether or not the predetermined control code in the stream is divided into a plurality of packets based on the information on the stream division position in 2), and the process proceeds to step (8-4).
A detailed determination method and a predetermined control code will be described later.

In step (8-4), step (8-
Based on the determination result of 3), a data block in which the control code is completed in the data block is created, and the process proceeds to step (8-5). A method for creating a data block in which the control code is completed within the data block will be described later.

In step (8-5), step (8-
A packet is created by adding a header to the data block created in 4). The packet and header are as described above. In step (8-6), the data packetization ends. Data packetization is performed by the above steps.

FIG. 9 shows another embodiment of a data packetizing method recorded on a computer-readable data recording medium according to the present invention.

In the figure, the operation is first started from step (9-1), and in step (9-2), the position at which the input stream is divided into streams is determined based on a predetermined packetization method. , Step (9-
Proceed to 3). The input stream is as described above. This step (9-2) is the same step as step (8-2).

In step (9-3), step (9-
Based on the information of the stream division position in 2), it is determined whether or not a data sequence composed of a part of the data and a part of the header in the stream is the same data sequence as a predetermined control code, Proceed to step (9-4). A detailed determination method will be described later.

In step (9-4), step (9-
Based on the determination result of 3), a data block that does not generate the same data sequence as the control code is created, and the process proceeds to step (9-5). A method of creating a data block that does not generate the same data series as the control code will be described later.

In step (9-5), step (9-
A packet is created by adding a header to the data block created in 4). The packet and header are as described above. This step is Step (8)
This is the same step as -5). In step (9-6), the data packetization ends. Data packetization is performed by the above steps.

Next, the predetermined packetization method will be described.

A description will be given using an example of the configuration of the packet shown in FIG. Generally, the packets (5-1, 5-2) include headers (5-3, 5-4) including information for synchronizing the streams, flags indicating the characteristics of the streams, and data of the streams. Data block (5-5,
5-6). The data blocks and packets are as described above. Packetization is performed by dividing the stream into data blocks and adding headers. Here, as the predetermined packetization method, a method of packetizing the data block length or packet length to be constant, or a method of dividing and packetizing a stream according to a fixed time interval, or A method combining these may be considered.

For example, in the method of packetizing a data block with a fixed length, a stream is divided into a predetermined data block length, and a packet is created by adding a header. An example in which the packet length is constant is described in Journal of the Institute of Image Information and Television Engineers, Vol. 51
No. 7 pp. As shown in 942-946 (1997), DVDs are determined to record data in units of 2048 bytes in length. In a transport stream (TS) of the MPEG-2 system standard used for satellite broadcasting or the like, a fixed-length TS packet is used, and packetization is performed so that the packet length is constant.

FIG. 10 shows a method of determining whether a predetermined control code is divided into a plurality of packets.
This shows step (8-3) in detail.

In the figure, first, step (10-1)
The operation is started from, the division position at the time of dividing the stream based on the predetermined packetization method is obtained, and the process proceeds to step (10-2). For example, if the predetermined packetization method is a packetization method that keeps the length of the packet constant, the length from the start position of the stream to the division position is obtained by subtracting the header length from the packet length. Obtained by pulling.

In step (10-2), step (1)
From the split position of the stream obtained by 0-1),
It is determined whether a predetermined control code exists at the division position. For example, this determination is made by preparing a control code table and comparing it with the data sequence at the division position. Through the above steps, it is determined whether the predetermined control code is divided into a plurality of packets.

FIG. 11 shows a method of creating a data block in which a predetermined control code is completed within the data block. This shows step (8-4) in detail.

In the figure, first, step (11-1)
The operation is started from step (8-3). If the predetermined control code obtained in step (8-3) is divided into a plurality of packets based on the determination result, the step (11-2) If not, go to step (11-4).

In step (11-2), the stream division position is changed to a position where the control code is not divided, the stream is divided, and the flow advances to step (11-3). For example, if the picture header in the MPEG-2 video standard is a corresponding control code, the position of division of the stream may be changed immediately before the picture header, and the control code may not be divided by dividing the stream. .

In step (11-3), step (1)
The stuffing data is inserted into the divided stream obtained by 1-2), and the process proceeds to step (11-5). For example, when performing packetization based on the MPEG-2 system standard, stuffing data is inserted before or after the divided stream. The length of the stuffing data is obtained by subtracting the length of the divided stream obtained in step (11-2) from the length of the required data block. The required data block length is obtained by the predetermined packetization method. For example, if the predetermined packetization method is a packetization method that keeps the length of the packet constant, the required data block length can be obtained by subtracting the header length from the packet length. If not necessary, the stuffing data need not be inserted. The stuffing data is as described above.

In step (11-4), the stream is divided according to the predetermined packetization method, and the flow advances to step (11-5). For example, if the predetermined packetization method is a packetization method that makes the length of a packet constant, the stream is divided into a length obtained by subtracting the length of the header from the length of the packet.

In step (11-5), step (1)
The data obtained by 1-3) or step (11-4) is defined as a data block. Through the above steps, a data block is created so that a predetermined control code is not divided into a plurality of packets.

FIG. 12 shows a method for determining whether or not a data sequence composed of data in a stream and a part of an added header becomes the same data sequence as a predetermined control code. This shows the step (9-3) in detail.

In the figure, first, step (12-1)
, And obtains a division position when dividing the stream based on the predetermined packetization method, and proceeds to step (12-2). This step is the same as step (10-1).

In step (12-2), step (1)
From the split position of the stream obtained by 2-1),
After comparing the data before and after the division position with the data of the header to be added, a table of a data sequence having the same length as the control code in a data sequence obtained by combining them is created, and the process proceeds to step (12-3). . If there are a plurality of control codes and the lengths are different, a table is created according to the lengths. For example, the length of the control code is 4 bytes, and the end of the stream before the division position is 0x000.
001, if the beginning of the packet to be added is 0x000001, 0x00000100, 0x0001000
Add 0, 0x01000001, etc. to the table.

In step (12-3), step (1)
The data series table obtained in 2-2) is compared with predetermined control data to determine whether or not the data series is the same. For example, this determination is made by preparing a control code table and comparing it with the table of step (12-2). When the data sequence table is the above example, if the control data table contains a picture start code (0x00000100), it is determined that the same data sequence exists. Through the above steps, it is determined whether or not the data sequence including the data in the stream and a part of the added header becomes the same data sequence as the predetermined control code.

FIG. 13 shows a method of creating a data block that does not generate the same data sequence as a predetermined control code. This shows the step (9-4) in detail.

In the figure, first, step (13-1)
From the step (9-3), and determine whether the data sequence consisting of the data in the stream obtained in the step (9-3) and a part of the added header becomes the same data sequence as the predetermined control code. If the same data sequence is generated from the determination result of (1), the process proceeds to step (13-2), and if the same data sequence is not generated, the process proceeds to step (13-4).

In the step (13-2), the stream dividing position is changed to a position where the same data series is not generated, the stream is divided, and the process proceeds to the step (13-3). For example, when a stream conforming to the MPEG-2 video standard is packetized according to the MPEG-2 system standard, a specific data string (0x0
0001), the picture start code (0x00000100) in the MPEG-2 video standard, which should be detected only in the data block, is combined with the first data string (0x000001E0) of the header of the next packet. It will appear at the border. In such a case, the problem can be avoided by changing the division position just before the specific data string and dividing the stream to create a data block.

In step (13-3), step (1)
The stuffing data is inserted into the divided stream obtained in 3-2), and the flow advances to step (13-5). For example, when performing packetization based on the MPEG-2 system standard, stuffing data is inserted before or after the divided stream. The length of the stuffing data is obtained by subtracting the length of the divided stream obtained in step (13-2) from the length of the required data block. The required data block length is obtained by the predetermined packetization method. For example, if the predetermined packetization method is a packetization method that keeps the length of the packet constant, the required data block length can be obtained by subtracting the header length from the packet length. If not necessary, the stuffing data need not be inserted. The stuffing data is as described above. This step is the same as step (11-3).

In step (13-4), the stream is divided according to the predetermined packetization method, and the flow advances to step (13-5). For example, if the predetermined packetization method is a packetization method that makes the length of a packet constant, the stream is divided into a length obtained by subtracting the length of the header from the length of the packet. This step is the same as step (11-4).

In step (13-5), step (1)
3-3) Or the data obtained in step (13-4) is used as a data block. This step is the same as step (11-5). Through the above steps, a data block is created so as not to generate the same data sequence as a predetermined control code.

Next, the predetermined control code will be described.

A description will be given using an example of the configuration of the packet and the control code shown in FIG. The packet (6-1) includes a header (6-2) and a data block (6-3). A data block is constituted by a stream. The control code (6-4) exists in the stream. The control code includes a start code or synchronization data indicating an information start position in the stream, an end code indicating an information end position in the stream (6-5), and a data string (6-6) accompanying these. For example, in the MPEG-2 standard, a sequence header, a picture header, a header of an audio access unit, an audio frame, audio sample data, and the like are control codes.

The sequence header starts with a sequence start code (0x000001B3) and has an accompanying data string such as bit rate information. The picture header starts with a picture start code (0x00000100) and has an accompanying data sequence such as a picture type. The header of the audio access unit starts with synchronous data (0xFFF) and has an accompanying data string such as a layer. There may be no accompanying data. The length of the control code may be adjusted to the length of the data to be detected in packet units. Control codes in the MPEG-2 standard are as described in the ISO / IEC 13818 standard.

FIG. 14 is a block diagram showing one embodiment of the present invention. A stream is divided into a plurality of data blocks by using a data packetizer (14-1), and a header is added to each data block. A method for creating a packet will be described.

In the figure, first, the division position detecting section (14)
-2) Input the stream. The division position detection unit outputs a stream division position when dividing the stream based on a predetermined packetization method. As a predetermined packetization method, a method of packetizing the data block length or the packet length so as to be constant, a method of dividing the stream according to a fixed time interval and packetizing, or a method of performing these Combined methods are conceivable. For example, if the predetermined packetization method is a packetization method that keeps the length of the packet constant, the length from the start position of the stream to the division position is obtained by subtracting the header length from the packet length. Obtained by pulling.

Next, the division position and the stream are input to the judgment section (14-3). The determining unit determines whether or not a predetermined control code exists at the division position from the division position of the input stream, and outputs a determination result. For example, this determination is made by preparing a control code table and comparing it with the data sequence at the division position.

Next, the determination result and the stream are input to the division position setting unit (14-4). The division position setting unit sets the division position of the stream so that the predetermined control code is completed in the data block. If the determination result is that the control code is not to be divided, the stream division position based on a predetermined packetization method is output by means similar to the division position detection unit (14-2), and the stream is divided. In such a case, the division position is changed and output so as not to divide the control code. For example, when a picture header in the MPEG-2 video standard is a corresponding control code, the control code can be prevented from being divided by changing a stream division position immediately before the picture header.

Next, the above-mentioned division position and stream are input to the stream division section (14-5). The stream division unit divides the input stream based on the input division position, and outputs the divided streams.

Next, the divided stream is input to the stuffing data insertion unit (14-6). The stuffing data insertion unit adds stuffing data to the input divided stream and outputs a data block. For example, when performing packetization based on the MPEG-2 system standard, stuffing data is inserted before or after the divided stream. The length of the stuffing data is obtained by subtracting the length of the divided stream from the length of the required data block. The required data block length is obtained by the predetermined packetization method. For example, if the predetermined packetization method is a packetization method that keeps the length of the packet constant, the required data block length can be obtained by subtracting the header length from the packet length. If not necessary, the stuffing data need not be inserted. The stuffing data is as described above.

Next, the above data block is input to the packet generator (14-7). The packet creation unit creates a packet by adding a header to the data block, and outputs the packet. The packet and header are as described above. By the above operation, a data block in which a predetermined control code included in the stream is completed in the data block is output.

FIG. 15 is a block diagram showing another embodiment of the present invention. The stream is divided into a plurality of data blocks using a data packetizing device (15-1), and a header is added to each data block. The method for creating a packet is described below.

In the figure, first, the division position detecting section (15)
-2) Input the stream. The division position detection unit outputs a stream division position when dividing the stream based on a predetermined packetization method. For example, if the predetermined packetization method is a packetization method that keeps the length of the packet constant, the length from the start position of the stream to the division position is obtained by subtracting the header length from the packet length. Obtained by pulling. This division position detection unit (1
5-2) is a unit similar to the division position detection unit (14-2).

Next, the above-mentioned division position and stream are inputted to the judgment section (15-3). When packetizing a stream based on a predetermined packetization method, the determination unit determines that a data sequence consisting of a part of data in the stream and a part of a header to be added is the same as a predetermined control code. The result of the determination as to whether or not the data series is to be output is output. After comparing the data before and after the input division position with the data of the added header, create a data sequence table with the same length as the control code in the data sequence that combines them, and compare it with the control code table. Is determined.

If there are a plurality of control codes and the lengths are different, a table is created in accordance with the lengths. For example, when a stream conforming to the MPEG-2 video standard is packetized according to the MPEG-2 system standard, the length of the control code is 4 bytes, the end of the stream immediately before the division position is 0x000001, and the start of the packet to be added is 0x000001. Is 0x00
000100, 0x00010000, 0x01000
001 and the like are created as a data series table, and this is compared with the control data table. The picture start code (0x0000010) is stored in the control data table.
0) is included, in this case, it is determined that the same data sequence exists.

Next, the above determination result and the stream are input to the division position setting section (15-4). The division position setting unit outputs, as a stream division position, a position where a data sequence including a part of data in the stream and a part of a header to be added does not become the same data sequence as a predetermined control code. If the result of the determination is that there is no data sequence identical to the control code, the stream division position based on a predetermined packetization method is output by means similar to the division position detection unit (15-2). If there is, the division position is changed and output so that the same control code is not generated.

For example, when a stream conforming to the MPEG-2 video standard is packetized according to the MPEG-2 system standard, if a specific data string (0x000001) exists at the end of the stream immediately before the division position, the header of the next packet First data string (0x000001E
In combination with (0), the picture start code (0x00000100) in the MPEG-2 video standard, which should be detected only in the data block, appears at the boundary of the packet. In such a case, the problem can be avoided by changing the division position immediately before the specific data string.

Next, the division position and the stream are input to the stream division unit (15-5). The stream division unit divides the input stream based on the input division position, and outputs the divided streams. The stream division unit (15-5)
This is the same means as -5).

Next, the divided stream is input to the stuffing data insertion unit (15-6). The stuffing data insertion unit adds stuffing data to the input divided stream and outputs a data block. For example, when performing packetization based on the MPEG-2 system standard, stuffing data is inserted before or after the divided stream.

The length of the stuffing data is obtained by subtracting the length of the divided stream from the length of the required data block. The required data block length is obtained by the predetermined packetization method. For example, if the predetermined packetization method is a packetization method that keeps the length of the packet constant, the required data block length can be obtained by subtracting the header length from the packet length. If not necessary, the stuffing data need not be inserted. The stuffing data is as described above. The stuffing data insertion unit (15-6) is provided with the stuffing data insertion unit (14).
-6).

Next, the above data block is input to the packet generator (15-7). The packet creation unit creates a packet by adding a header to the data block, and outputs the packet. The packet and header are as described above. This packet creation unit (15-7) is the same means as the packet creation unit (14-7). By the above operation, a data block is output in which the data sequence composed of a part of the data in the stream and a part of the added header does not become the same data sequence as a predetermined control code.

Although the above embodiment has been described by taking the MPEG-2 standard as an example, the present invention is not limited to this. Such a problem may occur not only in the MPEG-2 standard but also in general data encoding processing for packetization and multiplexing, and the present invention can be applied to other encoding processing. For example MP
EG-4 standard and the like. Further, it is also possible to transmit packetized data created by using the present invention by using communication means.

[0103]

According to the present invention, the generation of a control code divided into a plurality of packets and the generation of a pseudo start code are suppressed, and a packetized stream capable of detecting information such as a control code by individually examining packets is provided. This makes it possible to obtain an encoded data string that can be created and easily decoded and analyzed. This eliminates the need to disassemble the packet to detect the control code, simplifies the decoding and analysis device, and reduces the circuit scale.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of one embodiment of packetized data used in the present invention.

FIG. 2 is an explanatory diagram of packetized data in a conventional example.

FIG. 3 is an explanatory diagram of packetized data of another conventional example.

FIG. 4 is an explanatory diagram of another embodiment of packetized data used in the present invention.

FIG. 5 is an explanatory diagram showing an example of a general packet configuration.

FIG. 6 is an explanatory diagram of an example showing a configuration of a packet and a control code.

FIG. 7 is a block diagram showing a configuration example of a computer system used in the present invention.

FIG. 8 is a processing flowchart showing an example of a data packetizing method used in the present invention.

FIG. 9 is a processing flowchart showing an example of a data packetizing method used in the present invention.

FIG. 10 is a processing flowchart showing an example of a data packetizing method used in the present invention.

FIG. 11 is a processing flowchart showing an example of a data packetizing method used in the present invention.

FIG. 12 is a processing flowchart showing an example of a data packetizing method used in the present invention.

FIG. 13 is a processing flowchart showing an example of a data packetizing method used in the present invention.

FIG. 14 is a block diagram of a data packetizing apparatus according to one embodiment of the present invention.

FIG. 15 is a block diagram of a data packetizing apparatus according to another embodiment of the present invention.

[Explanation of symbols]

14-1 Data packetizer, 14-2 Division position detector, 14-3 Judgment unit, 14-4 Division position setting unit, 14-5 Stream division unit, 14-6 stuffing data insertion unit , 14-7 ... Packet creation unit.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Yoshito Neneko 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (72) Inventor Satoshi Date 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Central Research Laboratory (72) Inventor Tatsuto Suzuki 1-280 Higashi Koikekubo, Kokubunji City, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (72) Inventor Naoo Tanabe 1-280 Higashi Koigakubo, Kokubunji City, Tokyo F, Hitachi Central Research Laboratory Terms (reference) 5C053 FA02 FA14 FA20 FA24 GB06 GB37 JA21 KA05 KA24 LA11 5D044 AB05 AB07 BC06 CC04 DE02 DE03 DE22 DE32 DE37 DE52 GK08

Claims (14)

[Claims] 1. A data recording medium on which a discrete data sequence (hereinafter abbreviated as a stream) is recorded, in which a packet including an input stream and having a length determined according to a certain rule and a header is recorded. A data recording medium, wherein an input stream included in a data block of an arbitrary packet and a stream in which an input stream included in a subsequent packet is concatenated are determined by the certain rule from the beginning of the concatenated stream. A data recording medium, characterized in that a part of a predetermined control code exists at a position behind by a length, and stuffing data is inserted in a data block of the packet. 2. A data recording medium on which a stream is recorded, on which a packet including a data block including an input stream and having a length determined according to a certain rule and a header is recorded. And a stream obtained by concatenating the input stream included in the data block of the packet with the input stream included in the subsequent packet, exists at a position behind the head of the concatenated stream by the length determined by the certain rule. The data sequence is a data sequence that becomes the same data sequence as a predetermined control code by being combined with a part of a packet header, and stuffing data is inserted in a data block of the packet. A data recording medium. 3. The fixed rule is characterized in that, for each type of packet or for all packets, the rule is that the length of the data block of each packet or the length of the packet is constant. The data recording medium according to claim 1. 4. The control code according to claim 1, wherein the predetermined control code is a start code indicating an information start position in the stream, or synchronous data, an end code indicating an information end position in the stream, and a data string attached thereto. 3. The data recording medium according to claim 1, wherein: 5. A predetermined packetization method on a computer-readable recording medium in which a stream is divided into a plurality of data blocks, and a header is added to each data block to form a packet. A first step of packetizing the stream based on the first step, and a second step of determining whether the predetermined control code included in the stream is divided into a plurality of packets by the first step. A third step of creating a data block in which the control code is completed within the data block based on the determination result;
A computer-readable recording medium, wherein a data packetizing method comprising a fourth step of packetizing the data block based on the predetermined packetizing method is recorded. 6. A predetermined packetization method in a computer-readable recording medium in which a stream is divided into a plurality of data blocks, and a header is added to each data block to form a packet. And a data sequence consisting of a part of the data in the stream and a part of the header added by the fifth step is the same as a predetermined control code. A sixth step of determining whether or not the data series is to be formed, a seventh step of creating a data block that does not generate the same data series based on the determination result, and converting the data block into the predetermined packetization. A data packetizing method comprising an eighth step of packetizing based on the method is recorded. Wherein, the computer readable recording medium. 7. The packetization method according to claim 1, wherein:
It is characterized by a method of packetizing the data block length or the packet length so as to be constant, a method of dividing and packetizing a stream according to a fixed time interval, or a method of combining them. The computer-readable recording medium according to claim 5 or 6. 8. A method of determining whether or not a predetermined control code included in a stream is divided into a plurality of packets, the method comprising the steps of: 6. The computer-readable recording medium according to claim 5, wherein the determination is made by checking whether a predetermined control code exists at a division position of the stream divided by the division method. . 9. A method for creating a data block in which a control code is completed within a data block is performed by determining whether the predetermined control code is divided into a plurality of packets. If it is determined that the stream is divided to a position before or after the control code, the stream is divided, stuffing data is inserted to create a data block, and it is determined that the data block is not divided. 6. The computer-readable recording medium according to claim 5, wherein a method of creating a data block according to the predetermined packetization method is used in the case where the data block is used. 10. A method for determining whether a data sequence composed of a part of data in a stream and a part of an added header is the same data sequence as a predetermined control code, When a stream is divided by a predetermined packetization method, a data sequence including a part of data before and after a division position of the stream divided by the division method and a part of a header to be added is predetermined. 7. The computer-readable recording medium according to claim 6, wherein the method is a method of determining whether a data sequence is the same as a control code. 11. The method of creating a data block that does not generate the same data sequence is performed by the method of determining whether or not the data sequence is the same when the data block is determined to be the same data sequence. After the stream is divided by changing the division position of the stream to a position before or after a part of the data in the stream, stuffing data is inserted to create a data block, and it is determined that the data block does not become the same data series. 7. The computer-readable recording medium according to claim 6, wherein a data block is created in accordance with the predetermined packetization method. 12. The predetermined control code includes a start code or a synchronization data indicating an information start position in a stream, an end code indicating an information end position in a stream, and a data string attached thereto. The computer-readable recording medium according to any one of claims 5, 6, and 10, wherein: 13. A data recording apparatus for dividing a stream into a plurality of data blocks, adding a header to each data block to create and record a packet, wherein the stream is input and the predetermined packetizing method is performed. First means for outputting a stream division position at the time of dividing a stream based on the above, and the predetermined position included in the stream by the predetermined packetization method with the division position and the stream as inputs. A second means for outputting a determination result as to whether or not the control code is divided into a plurality of packets; and a stream in which the determination result and the stream are input, and wherein the predetermined control code is completed in a data block. A third means for outputting the division position of the above, an input of the division position and the stream, and outputting the divided stream Fourth means for inputting the divided stream, inserting stuffing data to output a data block, and inputting the data block, adding a header and packetizing the packet. 6. A data recording apparatus, comprising: a sixth means for outputting a data. 14. A data recording apparatus for dividing a stream into a plurality of data blocks, adding a header to each data block to create and record a packet, wherein the stream is input and the predetermined packetizing method is performed. Means for outputting a stream division position when the stream is divided on the basis of the above, inputting the division position and the stream, and adding a part of the data in the data block by the predetermined packetization method. Eighth means for outputting a result of determination as to whether or not a data sequence consisting of a part of the header to be performed is the same data sequence as the predetermined control code, and inputting the determination result and the stream,
Ninth means for outputting a division position of a stream that does not generate the same data sequence as the predetermined control code, and tenth means for receiving the division position and the stream as input and outputting the divided stream An eleventh means for receiving the divided stream as input, inserting stuffing data to output a data block, and a twelfth means for inputting the data block as input, adding a header, packetizing the packet, and outputting a packet. A data recording device comprising: