JPH10285210A - Packetizing method and depacketizing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently utilize a recording medium and a transmission medium by erasing the specified bit pattern of picture data or the header of voice, etc., and adding a packet header to the position. SOLUTION: A picture encoder 101 inputs a picture frame, outputs picture data which is encoded by MPEGs 1, 2 or 4 to a packet converting device 102 and stores it in a buffer 103. A processor 104 detects the specified bit pattern included in picture data, for example, 0000 0000 0000 0000 0000 0001 so as to erase it, generates the packet header and inserts it in the erasion position. That is, 23 bits are inputted from the buffer to a 24-bit register so as to execute initialization. One bit shift to left is executed in the register, one bit is inputted from the buffer so as to obtain a logical sum with the register, the value of the register is inspected, the packet header is outputted when the specified bit pattern is detected and the highest order bit of the register is outputted unless it is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packetizing method for packetizing digital data for transmission or recording, and to an inverse packetizer for restoring digital data from packetized data.

[0002]

2. Description of the Related Art MPEG2 (reference: ISO / IEC JTC1 / SC29 / WG11N) is an international standard method of packetizing digital data when transmitting or recording packetized digital data.
801, "ISO / IEC 13818-1 International Standard: INFO
RMATION TECHNOLOGY-GENERICCODING OF MOVING PICTU
RES AND ASSOCIATED AUDIO: SYSTEMS ", 1994/11). A packetization method in MPEG2 will be described with reference to Fig. 15. Fig. 15 is a conceptual data diagram for explaining a packetization method in MPEG2. 15, (a) shows image data encoded by MPEG2,
(B) shows image data packetized by MPEG2. (B) shows audio data encoded by MPEG2, and (d) shows audio data packetized by MPEG2.

As shown in FIG. 1A, a sequence start code is first added to image data. Further, a picture start code is added to the head of the data of one frame of the image. In addition, various start codes are present in the image data, such as a slice start code added to the beginning of each slice in the frame. These start codes need to be the only bit pattern in the image data, and therefore have a relatively long bit length. Each start code is 32 bits, and is divided into a bit pattern common to each 24-bit start code and a bit pattern indicating the type of an 8-bit start code. The common bit pattern is 0000 0
000 0000 0000 0000 0001. The bit pattern indicating the type of the 8-bit start code is, for example,
The sequence start code is 1011 0011, and the picture start code is 0000 0000.

In the packetization method of MPEG2, FIG.
As shown in (b), the image data is divided at an appropriate length, and a PES (Packetized Elementary Stream) packet header is added. The PES packet header starts with a 32-bit start code for indicating a PES packet header. 16 types of PES packet start codes are prepared for image data. Therefore, 16 types of image data can be multiplexed in one data stream.

[0005] As shown in (b), a frame header is added to audio data at substantially constant intervals. The frame header specifies the compression bit rate and compression method of the following audio data, and the contents of the frame header are often the same. The number of bits of the frame header is 32 bits.

In the MPEG2 packet method, FIG.
As shown in (d), audio data is divided at an appropriate length, and a PES packet header is added as in the case of image data. 32 types of PES packet start codes are prepared for audio data. Therefore,
32 types of audio data can be multiplexed in one data stream.

As described above, by converting into PES packets, it is possible to multiplex 16 types of image data and 32 types of audio data coded by MPEG2 in one data stream and transmit or record them. Become.

[0008]

The common 24-bit bit pattern in the start code is indispensable for identifying the type of the start code when recording or transmitting only image data.
However, when recording or transmitting in the form of a PES packet, depending on the configuration method of the PES packet, 24
It is not necessary to record or transmit a common bit pattern or start code of bits as it is. However, in the conventional MPEG2 packetization method, 2
Since the common 4-bit bit pattern or start code is stored as it is in the data portion of the PES packet, a redundant component is recorded or transmitted on the recording medium or transmission medium. These cause a reduction in the recording time in the recording medium or an increase in the transmission rate in the transmission medium. Also, the same problem as the start code of the image data occurs in the frame header of the audio data.

[0009]

In order to solve the above-mentioned problems, a packetizing method according to the present invention comprises the steps of: inputting digital data; detecting a specific bit pattern from the digital data; A specific bit pattern is deleted, a packet header is created, inserted at the position where the specific bit pattern is deleted, and output.

[0010] Further, the packetization method according to the present invention comprises:
When digital data is input and a specific bit pattern is detected from the digital data, the specific bit pattern is deleted from the digital data, and a packet header including a code indicating that the specific bit pattern is deleted is created. Then, the specific bit pattern is inserted at the deleted position.

The depacketizing apparatus according to the present invention comprises: input means for inputting packet data; bit pattern output means for outputting a specific bit pattern when a packet header of the packet data is detected; Digital data output means for removing the packet header from the digital data output means, and a data multiplexing means for multiplexing and outputting the bit pattern output by the bit pattern output means and the output digital data of the digital data output means. Is provided.

Further, the depacketizing apparatus according to the present invention includes an input means for inputting packet data, a packet of the packet data, a code indicating that a specific bit pattern in a packet header has been deleted, is checked. A bit pattern output unit that outputs the specific bit pattern when the code indicates that the specific bit pattern is deleted, and a digital data output unit that outputs the digital data by deleting the packet header from the packet data. Data multiplexing means for multiplexing and outputting the bit pattern output from the bit pattern output means and the digital data output from the digital data output means.

Further, in order to solve the redundancy when packetizing and transmitting digital data to which a header is added for every N bits (N is a natural number), the packetizing method of the present invention uses In a packetizing method for inserting a packet header immediately before a start position of the header and outputting packet data including the packet header and the digital data, the m-th header of the digital data may be an (m-1) -th header If it is the same as above, the m-th header is deleted from the digital data, and a code indicating that the m-th header is deleted from the digital data is added to the packet header.

Further, in the packetizing method according to the present invention, in the packet header, the m-th header is the m-th header.
When it is the same as the first header, the value does not change,
When the i-th header is not the same as the (m-1) -th header, the header includes a header change discrimination code whose value changes.

Further, the depacketizing apparatus of the present invention comprises an input means for inputting packet data, a packet header of the packet data, a code indicating that the header of the digital data is deleted, and a check for the code. When indicating that the header of the digital data has not been deleted, the same data as the header of the digital data is created and stored in the memory, and when the code indicates that the header of the digital data has been deleted, the data is stored in the memory. Header deletion determining means for outputting the stored header data; digital data output means for deleting the packet header from the packet data to output digital data; header data for the header output means and digital data for the digital data output means. Data multiplexing means for multiplexing and outputting data.

Further, in the depacketizing apparatus according to the present invention, the header deletion judging means detects a packet header of the packet data and checks a code indicating that the header of the digital data has been deleted. If the header of the digital data is not deleted, the header of the digital data is stored in the memory and the header change determination code is stored in the memory, and the code indicating that the header of the digital data is deleted is digital. If the header of the data is deleted, the header change discrimination code stored in the memory is further compared with the header change discrimination code added to the packet header of the packet data input by the packet means, so that they match. In this case, the header stored in the memory is output.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) A packetizing apparatus according to Embodiment 1 for describing a packetizing method of the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram of a packetizing apparatus according to a first embodiment for explaining a packetizing method according to the present invention. In FIG. 1, reference numeral 101 denotes an image encoder, 10
Reference numeral 2 denotes a packetizing device, which includes a buffer 103 and a processor 104. FIG. 2 is a flowchart for explaining a part of the operation of the processor 104.

An image encoder 101 receives an image frame, and outputs image data encoded by MPEG1, MPEG2 or MPEG4 to a packetizing device 102. The packetizer 102 stores the input image data in the buffer 103. The processor 104 generates a specific bit pattern 0000 0000 00 included in the image data.
00 0000 0000 0001 (0x000001 in hexadecimal notation) is detected and deleted, a packet header is created, and the packet header is inserted at the position where the bit pattern was deleted. This specific procedure will be described with reference to the flowchart of FIG. First, in step 201, 23 bits are input to the register R from the buffer 103 and initialized. R is a 24-bit register. Next, in step 202, the register R is shifted one bit to the left, and in step 203, one bit is input from the buffer and the logical sum with the register R is obtained. Further, in step 204, the value of the register R is checked to see if it matches a specific bit pattern. In Embodiment 1, 0000 0
Let 000 0000 0000 0000 0001 be a specific bit pattern. If the register R matches the specific bit pattern, a packet header is created and output in step 205, and the
And 23 bits are input from the buffer 103 to reinitialize. That is, when a specific bit pattern is detected, the packet header is output and the specific bit pattern is not output. If the register R does not match the specific bit pattern in step 204, step 2
In 07, the MSB (Most Significant B) of the register R
it, the most significant bit).

The packetizing apparatus according to the first embodiment of the packetizing method of the present invention has been described above.

In the first embodiment, the specific bit pattern is 24-bit 0x000001. However, the present invention is not limited to this. For example, a sequence start code or a picture start code in MPEG1 or MPEG2, a video object in MPEG4 layer·
It is possible to use a start code, a resync marker code, an MPEG1 audio frame header, or the like.

The packet data output from the packetizing apparatus according to the first embodiment can be recorded on a recording medium such as a floppy disk, a hard disk, or a digital versatile disk. This is effective when packet data is stored or carried. Further, the packet data output from the packetizing apparatus according to the first embodiment can be transmitted by an optical fiber cable, a wired transmission medium such as Ethernet, or a wireless transmission medium. This is effective when transmitting packet data to a remote place.

(Embodiment 2) A packetizing apparatus according to Embodiment 2 for describing a packetizing method of the present invention will be described with reference to FIGS. 1, 3 and 4. FIG.

In the second embodiment, two or more specific bit patterns are checked, and when each bit pattern is detected, the bit pattern is deleted and a packet header having a code indicating the deleted bit pattern is added. And insert it at the position where the bit pattern was deleted,
It differs from the first embodiment in that it outputs.

In FIG. 1, an image encoder 101 receives an image frame and outputs image data encoded by MPEG2 or MPEG4 to a packetizer 102. The packetizer 102 stores the input image data in the buffer 103. The processor 104 detects and deletes a plurality of specific bit patterns included in the image data, creates a packet header including a flag indicating that the specific bit pattern has been deleted, and generates a packet header at a position where the bit pattern is deleted. Insert packet header. This specific procedure will be described with reference to the flowchart of FIG. First, in step 301, 31 bits are input to the register R from the buffer 103 and initialized. R is a 32-bit register. Then step 3
02, the value of the register R is shifted one bit to the left,
In step 303, one bit is input from the buffer,
The logical sum with the register R is calculated. In step 304, it is checked whether or not the register R matches a specific bit pattern 0x000001B3. Register R value is 0x000001B3
If it matches, in step 305, a packet header in which the code indicating that the specific bit pattern has been deleted is set to 1 is created and output. In step 306, 31 bits are input to the register R from the buffer 103 and reinitialized. Step 304
If the value of the register R does not match 0x000001B3, it is checked in step 307 whether the register R matches another specific bit pattern 0x00000100.
If the value of the register R is equal to 0x00000100, a packet header in which the sign indicating that the specific bit pattern has been deleted is set to 0 in step 308, and the packet header is output in step 309. And returns to step 302. If the value of register R does not match any particular bit pattern, then at step 310 the MSB of register R
Is output. If the value of the code indicating that the specific bit pattern has been deleted is 1, it indicates that the bit pattern 0x000001B3 has been deleted, and if the value of the code indicating that the specific bit pattern has been deleted is 0, the bit pattern 0x0000.
Indicates that 0100 has been deleted.

FIG. 4 shows an example of packet data created by the packetizer in the second embodiment. FIG. 4 (a)
The packet header is inserted into the image data in the buffer 103 shown in FIG. At this time, specific bit patterns 0x000001B3 and 0x0000 in the image data of FIG.
4B is deleted in FIG. 4B, and as shown in the contents of the packet header in FIG. 4C, a code indicating that a specific bit pattern of the packet header is deleted is changed to a value indicating the deleted bit pattern. Is set.

The packetizing apparatus according to the second embodiment of the packetizing method of the present invention has been described.

In the second embodiment, the specific bit pattern is a 32-bit bit pattern, 0x000001.
B3 and 0x00000100 are used, but the number of bits of the bit pattern and the type of the bit pattern are not limited thereto. For example, a video object layer start code, a video object start code, a resync marker code, or the like in MPEG4 is used. It is possible.

In the second embodiment, a code indicating that a specific bit pattern has been deleted is represented by 1 bit. However, when there are three or more specific bit patterns, a code of 2 bits or more is replaced by a code. It can be used.

The packet data output from the packetizer according to the second embodiment can be recorded on a recording medium such as a floppy disk, a hard disk, or a digital versatile disk. Further, the packet data output from the packetizing device according to the second embodiment can be transmitted by an optical fiber cable, a wired transmission medium such as Ethernet, or a wireless transmission medium.

(Embodiment 3) Embodiment 3 for describing the depacketizing apparatus of the present invention will be described with reference to FIGS. FIG. 5 is a block diagram of Embodiment 3 for explaining the depacketizing apparatus of the present invention. In FIG. 5, reference numeral 501 denotes a buffer, 502 denotes a bit pattern output unit, 503 denotes a digital data output unit,
504 is a data multiplexing unit. Also, in FIG.
510 is a bit pattern, 511 is digital data from which a packet header is deleted, and 512 is multiplexed data in which 510 and 511 are multiplexed. FIG. 6 is a flowchart for explaining the operation of the bit pattern output means 502.

The buffer 501 stores the input packet data. Packet data according to the first embodiment of the present invention
Are output by the packetizer described in FIG. The bit pattern output means 502 operates based on the flowchart shown in FIG. In step 601, packet data of the buffer 501 is input to detect a packet header, and in step 602, the bit pattern 5
As 0, 0x000001 is output. The digital data output means 503 outputs digital data 511 from which the packet header has been deleted. The data multiplexing means 504 inputs the bit pattern 510 when the bit pattern output means 502 outputs the bit pattern 510, and then inputs the digital data 51.
1 and outputs multiplexed digital data 512. Therefore, the multiplexed digital data 512 outputs the same data as the image data output from the image encoder 101 in FIG.

The third embodiment which is the depacketizing apparatus of the present invention has been described. In the third embodiment, the specific bit pattern is a 24-bit bit pattern, 0x000001, but is not limited to this.
For example, it is possible to use a sequence start code or a picture start code of MPEG1 or MPEG2, a video object layer start code of MPEG4, a resync marker code, or an audio frame header of MPEG1.

In the third embodiment, the bit pattern output means 502, the digital data output means 503, and the data multiplexing means 504 are used.
It can be realized by software processing by one processor.

As described above, according to the third embodiment, since the specific bit pattern of the image data which has been deleted from the packet data is restored by the depacketizer, the image data to which the multiplexed data 512 is input is input. The decoding device and the like can be used with the conventional configuration. Further, there is no need to record or transmit a redundant component when recording or transmitting packet data, that is, a specific bit pattern, so that a recording medium or a transmission medium can be used efficiently.

(Embodiment 4) FIGS. 4 and 5 show Embodiment 4 for explaining the depacketizing apparatus of the present invention.
This will be described with reference to FIG. FIG. 7 is a flowchart for explaining the operation of bit pattern output means 502 in FIG. 5 in Embodiment 4 of the depacketizing apparatus of the present invention.

Embodiment 4 differs from Embodiment 3 in the operation of bit pattern output means 502. Embodiment 4
The operation of the bit pattern output means 502 will be described with reference to the flowchart of FIG. In step 701, the packet data in the buffer 501 is input and a packet header is detected. The input packet data has a packet header as shown in FIG. In step 702, a code indicating that the specific bit pattern in the packet header has been deleted is checked. If the code value is 1, 0x000001B3 is output as the bit pattern 510 in step 703, and if the code value is 0. Outputs 0x00000100 as the bit pattern 510 in step 704. The digital data output means 503 outputs digital data 511 from which the packet header has been deleted. Data multiplexing means 504
When the bit pattern 510 is output from the bit pattern output means 502, the input 510 is input, then the digital data 511 is input, and the multiplexed digital data 512 is output. Therefore, the multiplexed digital data 512 outputs the same data as the image data output from the image encoder 101 in FIG.

The fourth embodiment, which is the reverse packetizer of the present invention, has been described above. In the fourth embodiment, the specific bit patterns are two 32-bit bit patterns, 0x000001B3 and 0x00000100.
Both the number of bits of the bit pattern and the type of the bit pattern are not limited to these, and for example, a video object layer start code, a video object start code, a resync marker code, or the like in MPEG4 can be used.

In the fourth embodiment, a code indicating that a specific bit pattern has been deleted is represented by one bit. However, if there are three or more types of bit patterns to be deleted, a code of two bits or more is replaced with one bit. It can be used.

In the third embodiment, the bit pattern output means 502, the digital data output means 503, and the data multiplexing means 504 are used.
It can be realized by software processing by one processor.

As described above, according to the fourth embodiment, the specific bit pattern of the image data, which has been deleted from the packet data, is restored by the depacketizer, so that the multiplexed data 512 The decoding device and the like can be used with the conventional configuration.

(Embodiment 5) A packetizing apparatus according to Embodiment 5 for describing the packetizing method of the present invention will be described with reference to FIGS. FIG. 8 is a block diagram of a packetizing apparatus according to a fifth embodiment of the present invention. In FIG. 8, reference numeral 801 denotes a speech encoder;
Is a packetizing device, which comprises a buffer 803, a processor 804, and a memory 805. FIG. 9 is a flowchart for explaining the operation of the processor 804.

An audio encoder 801 receives audio data, converts the input audio data into frames for a fixed time, and outputs MPEG1 and MPEG data.
2 or MPEG4, and outputs frame data with a header added to the frame. For example, if the sampling frequency is 48 kHz for layer 2 of MPEG1, encoding is performed as a frame every 24 milliseconds. The packetizer 802 stores the input frame data in the buffer 803. Processor 804
Operates according to the flowchart shown in FIG.
In step 901, one frame of audio data is input from the buffer 803, and the header of the frame is stored in the memory 80.
5 is stored. Next, in step 902, a packet header in which the value of the code indicating that the header has been deleted is set to 0 is created, and this is added to the head of the frame data input in step 901 and output. Step 903
In step 904, one frame of audio data is input from the buffer 803, and in step 904, it is checked whether the header of the input frame data matches the header stored in the memory 805. If the header of the input frame data matches the header stored in the memory, step 90
In step 5, the header is deleted from the input frame data, a packet header in which the value of the code indicating that the header has been deleted is set to 1 is added to the head of the frame data from which the header has been deleted, and the packet data is output. If it is determined in step 904 that the header of the input frame data does not match the header stored in the memory, in step 906,
A packet header in which the value of the code indicating that the header has been deleted is set to 0 is created, and this is added to the head of the input frame data and output. In step 907, the header of the frame data stored in the memory 805 is replaced with the header of the frame data input in step 903.

The fifth embodiment which is the packetizing apparatus of the present invention has been described. The packet data output from the packetizing apparatus according to the fifth embodiment can be recorded on a recording medium such as a floppy disk, a hard disk, or a digital versatile disk. Further, the packet data output from the packetizing device according to the second embodiment can be transmitted by an optical fiber cable, a wired transmission medium such as Ethernet, or a wireless transmission medium.

According to the fifth embodiment, when the content of the header of the frame data is constant, the packet data in which the header of the frame data of the second and subsequent frames is deleted is output. Efficient storage and transmission becomes possible.

In the fifth embodiment, when the header of the input frame data matches the header stored in the memory, the header of the frame data is always deleted. However, the present invention is not limited to this. When the deletion occurs continuously P times or Q seconds, even if the header of the input frame data matches the header stored in the memory, a packet whose header is not deleted may be output. For example, 20 as P and 0.5 as Q
Seconds and the like can be set. This is effective as a measure against packet data transmission errors and recording errors. Also, in a depacketizing device that inputs packet data from the middle and depackets it, the operation when packet data is received from the middle can be guaranteed.

In the fifth embodiment, the input data is an audio frame. However, the present invention is not limited to this. It is assumed that the header having the same content appears repeatedly in the data and the content of the header is substantially constant. Digital data can be used as input.

(Embodiment 6) A packetizing apparatus according to Embodiment 6 for describing the packetizing method of the present invention will be described with reference to FIGS. 8, 10 and 11. FIG. FIG. 8 is a block diagram of a packetizing apparatus according to a sixth embodiment of the present invention. FIG.
5 is a flowchart for explaining the operation of FIG. Also,
FIG. 11 is a data configuration diagram for explaining an operation of the packetizing apparatus according to the sixth embodiment.

The packetizer in the sixth embodiment is
The operation of the processor 804 is partially different from the packetization device described in the fifth embodiment. The operation of the processor 804 will be described with reference to the flowchart shown in FIG. First, in step 1001, N is defined as a variable used inside the processor, and the value of N is set to 0. Next, in step 1002, one frame of audio data is input from the buffer 803, the same data as the header of the frame is created, and stored in the memory 805.
03, the value of the header deletion code is set to 0, the value of the header deletion number is set to the value indicated by N, that is, a packet header is set to 0, and further, in step 1004,
In step 1002, a packet header is added to the head of the input frame and output. The configuration of the packet data at this time is such that the value of the header deletion code is set to 0 and the value of the header deletion number is set to N in the packet header as shown in FIG. The header deletion code is 1 bit,
A value of 0 indicates that the header of the frame has not been deleted, and a value of 1 indicates that the header of the frame has been deleted. The header deletion number is a 3-bit code, and is a value that is incremented by one when the header stored in the memory and the input header do not match, and becomes 0 after counting up from 0 to 7. It will return. In FIG. 11A, the input voice frame follows the packet header. Next, in step 1005, one frame of audio data is input from the buffer 803, and in step 1006, if the header of the input frame matches the header stored in the memory 803 and the header matches, the flow proceeds to step 1007. A packet header in which the value of the header deletion code is set to 1 and the value of the header deletion number is set to the value indicated by N, that is, 0, is created. And output. The configuration of the packet data at this time is such that the value of the header deletion code is set to 1 and the value of the header deletion number is set to N in the packet header as shown in FIG. Data following the packet header is a frame from which the header has been deleted. Step 1006
, The header of the input frame and the memory 80
If the headers stored in step 3 are different, step 10
At step 09, data having the same content as the header of the input frame is overwritten and stored in the memory 803. Further, in step 1010, the variable N is incremented by one. If the value is incremented when the value of the variable N is 7, it returns to 0. In step 1011, the header deletion code is set to 0, and a packet header in which the header deletion number is set to the value of N is created. In step 1012, the packet header is added to the head of the input frame and output. Return to

The embodiment 6 which is the packetizing apparatus of the present invention has been described above. Packet data output from the packetizing apparatus according to the sixth embodiment can be recorded on a recording medium such as a floppy disk, a hard disk, or a digital versatile disk. Further, the packet data output from the packetizing apparatus according to the second embodiment can be transmitted by an optical fiber cable, a wired transmission medium such as Ethernet, or a wireless transmission medium.

In the sixth embodiment, when the value of the header deletion code is 0, it indicates that the header is not deleted. However, when it is 1, it may indicate that the header is not deleted. Although the initial value of the header deletion number is set to 0, it may be a numerical value other than 0. Furthermore, although the number of bits of the header deletion number is set to 3 bits, the number of bits other than 3 bits may be used.

In the sixth embodiment, the input data is an audio frame. However, the present invention is not limited to this. It is assumed that the header having the same content appears repeatedly in the data and the content of the header is substantially constant. Digital data can be used as input.

(Embodiment 7) Embodiment 7 for describing the depacketizing apparatus of the present invention will be described with reference to FIGS. FIG. 12 is a block diagram of Embodiment 7 for explaining the depacketizing apparatus of the present invention. In FIG. 12, reference numeral 1201 denotes a buffer;
2 is a header deletion determining unit, 1203 is a memory, 1204
Denotes a digital data output unit, and 1205 denotes a data multiplexing unit. 1210 is a header, 1211 is data obtained by removing a packet header from packet data,
Is multiplexed data obtained by multiplexing 1210 and 1211. FIG. 13 is a flowchart for explaining the operation of the header deletion determining means 1202.

The depacketizer inputs the packet data to the buffer 1201. The packet header in the packet data includes the header deletion code described in the sixth embodiment. Header deletion determining means 120
2 inputs packet data from the buffer 1201. The operation of the header deletion determining means will be described with reference to the flowchart of FIG. First, in step 1301, packet data is input. In step 1302, the header deletion code in the packet header is checked. If this value is 0, in step 1303, the digital data header immediately after the packet header is stored in the memory 12
03 is stored. In step 1302, the header deletion code in the packet header is checked. If this value is 1, in step 1304, the memory 1203
The header 1210 of the digital data stored in the
It is read out from 203 and output. Digital data output means 1204 receives the packet data, deletes the packet header, and outputs digital data 1211. The data multiplexing means 1205 inputs the header 1210 output from the header deletion determination means, if any, inputs the digital data 1211 output from the digital data output means, and adds the header 1210 to the head of the digital data 1211. The data 1212 is output. If the header 1210 is not output, the digital data 121
Outputs 1.

The embodiment 7 which is the depacketizing apparatus according to the present invention has been described above. According to Embodiment 7,
Since the header added to each frame of the digital data which has been deleted from the packet data is restored by the depacketizer, the multiplexed data 1212
Can be used with the conventional configuration. Further, there is no need to record or transmit a redundant component when recording or transmitting packet data, that is, a header having the same content continuously, and it is possible to use a recording medium or a transmission medium efficiently.

(Embodiment 8) Embodiment 7 for describing the depacketizing apparatus of the present invention will be described with reference to FIGS. FIG. 12 is a block diagram for explaining the depacketizing apparatus according to the eighth embodiment, and has the same configuration as that of the seventh embodiment. Embodiment 7
Means the operation of the header deletion determining means 1202 and the memory 120
3 is different. The operation of header deletion determination means 1202 in the eighth embodiment will be described with reference to the flowchart in FIG. First, step 1401
Input the packet data. The packet header of the input packet data includes the header deletion code and the header deletion number described in the sixth embodiment. In step 1402, the header deletion code in the packet header is checked, and if this value is 0,
In step 1403, the header deletion number is stored in the memory 12
03, and in step 1404, the digital data header immediately after the packet header is stored in the memory 1203. In step 1402, the header deletion code in the packet header is checked, and if this value is 1
In step 1405, the header deletion number in the input packet header and step 14
03, the header deletion number stored in the memory 1203 is compared.
In step 6, the digital data header 1210 stored in the memory 1203 is output. Regarding the operation of the digital data output unit 1204 and the data multiplexing unit 1205,
The description is omitted because it is similar to the seventh embodiment.

The embodiment 8 which is the depacketizing apparatus according to the present invention has been described above. In the eighth embodiment, the output of the header of digital data stored in the memory is determined by checking the header deletion number. Therefore, if packet data is lost on the way and the header information is changed in the lost packet, an erroneous In order to prevent the output of the header, the operation of the decoding device or the like for inputting the output of the depacketizing device,
More reliable than in the seventh embodiment.

[0059]

As described above, according to the packetizing method and the depacketizing apparatus of the present invention, when image data or audio data is packetized and recorded or transmitted, a redundant component, that is, an image data A recording medium or transmission medium for deleting a specific bit pattern such as a start code, a header in an audio frame, and the like, and adding a packet header to the deleted position or adding a packet header to which a code indicating the deletion is added. Can be used efficiently.

Further, according to the depacketizing apparatus of the present invention, when a packet header is detected, a specific bit pattern such as a start code in image data deleted in the image data and a header in an audio frame are added and output. Thus, it is possible to obtain an effect that it can be used in a decoding device or the like for inputting image data or audio data without changing the conventional configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram of a packetizing apparatus according to Embodiments 1 and 2 of the present invention.

FIG. 2 is a flowchart illustrating a packetizing apparatus according to Embodiment 1 of the present invention.

FIG. 3 is a flowchart illustrating a packetizing apparatus according to a second embodiment of the present invention.

FIG. 4 is a data configuration diagram for describing a packetizing device according to a second embodiment of the present invention.

FIG. 5 is a block diagram illustrating a depacketizing apparatus according to Embodiments 3 and 4 of the present invention.

FIG. 6 is a flowchart illustrating a depacketizing apparatus according to a third embodiment of the present invention.

FIG. 7 is a flowchart illustrating a depacketizing apparatus according to a fourth embodiment of the present invention.

FIG. 8 is a block diagram for explaining a packetizing apparatus according to the fifth and sixth embodiments of the present invention.

FIG. 9 is a flowchart illustrating a packetizing apparatus according to a fifth embodiment of the present invention.

FIG. 10 is a flowchart illustrating a packetizing apparatus according to a sixth embodiment of the present invention.

FIG. 11 is a data configuration diagram for describing a packetizing device according to a sixth embodiment of the present invention.

FIG. 12 is a block diagram illustrating a depacketizing apparatus according to Embodiments 7 and 8 of the present invention.

FIG. 13 is a flowchart illustrating a depacketizing apparatus according to a seventh embodiment of the present invention.

FIG. 14 is a flowchart illustrating a depacketizing apparatus according to an eighth embodiment of the present invention.

FIG. 15 is a conceptual data diagram for explaining an MPEG2 packetization method in a conventional example.

[Explanation of symbols]

 101 packetizer 401 input image data 402 output packet data 403 packet header 404 packet header 802 packetizer

Claims (12)

[Claims] 1. When digital data is input and a specific bit pattern is detected from the digital data, the specific bit pattern is deleted from the digital data, a packet header is created, and the specific bit pattern is changed. A packetizing method, wherein the packet is inserted at the position where the packet is deleted and output. 2. The packetizing method according to claim 1, wherein the packet header includes a code indicating that the specific bit pattern has been deleted. 3. The specific bit pattern is 0000 0000
2. The value of 0000 0000 0000 0001.
3. The packetization method according to any one of claims 1 to 2. 4. An input means for inputting packet data,
A bit pattern output unit that outputs a specific bit pattern when a packet header of the packet data is detected; a digital data output unit that deletes the packet header from the packet data to output digital data; A depacketizing device comprising: a data multiplexing unit that multiplexes and outputs a bit pattern output by a unit and digital data output by the digital data output unit. 5. An input means for inputting packet data,
The packet of the packet data is detected, a code indicating that the specific bit pattern in the packet header has been deleted is checked, and if the code indicates that the specific bit pattern has been deleted, the specific bit pattern is output. Bit pattern output means, digital data output means for removing the packet header from the packet data and outputting digital data, bit pattern output by the bit pattern output means and output digital data of the digital data output means. And a data multiplexing means for multiplexing and outputting. 6. Digital data to which a header is added for every N bits (N is a natural number) is input, and a packet header is inserted immediately before a start position of the header in the digital data. In a packetization method for outputting packet data composed of data,
When the m-th header of the digital data is the same as the (m-1) -th header, the m-th header is deleted from the digital data, and the m-th header is deleted from the digital data in the packet header. A packetization method comprising adding a code indicating that a header has been deleted. 7. When the m-th header is the same as the (m-1) -th header P times (P is an integer of 2 or more) continuously, the m-th header is not deleted. 7. The packetizing method according to claim 6, wherein: 8. The packet header does not change when the m-th header is the same as the (m-1) -th header, and the m-th header is the same as the (m-1) -th header. 7. The packetizing method according to claim 6, further comprising a header change discrimination code whose value changes when not. 9. An input means for inputting packet data,
The packet header of the packet data is detected, and a code indicating that the header of the digital data has been deleted is checked. If the code indicates that the header of the digital data has not been deleted, the same data as the header of the digital data is used. Create and store in the memory, header deletion determination means to output the header data stored in the memory when the code indicates that the header of the digital data has been deleted,
Digital data output means for outputting the digital data by removing the packet header from the packet data,
A demultiplexing apparatus comprising: a data multiplexing unit that multiplexes and outputs header data of the header output unit and digital data of the digital data output unit. 10. The header deletion determining means detects a packet header of the packet data, checks a code indicating that the digital data header has been deleted, and determines that the code does not delete the digital data header. When indicating, the header of the digital data is stored in the memory and the header change determination code is stored in the memory, and the code indicating that the header of the digital data has been deleted has deleted the header of the digital data. When the header change discrimination code stored in the memory is further compared with the header change discrimination code added to the packet header of the packet data input by the packet means, if the header change discrimination code matches, the header stored in the memory is further compared. The depacketizer according to claim 9, wherein the output is output. 11. A recording medium for recording packet data output by the packetizing method according to claim 1. 12. A transmission medium for transmitting packet data output by the packetization method according to any one of claims 1, 2, 3, 6, 7, and 8.