JP2003229828A - Method for inserting synchronous pattern and method for removing synchronous pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize synchronous pattern removal processing for performing conversion so as not to be a synchronous pattern by inserting delimiter data into a bit string coinciding with a synchronous pattern in an encoded signal with a small amount of processing. <P>SOLUTION: If a bit string coinciding with a synchronous pattern is detected at any place other than a place where a synchronous pattern is originally located in the encoded signal, a prescribed bit string whose insertion result does not become a synchronous pattern is inserted before the last bit in the bit string coinciding with the synchronous pattern and also at the last byte boundary in the bit string. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronization pattern insertion method and a synchronization pattern removal method for removing / inserting a synchronization pattern in a coded signal, and a recording medium having a program for implementing the same implemented by software. It is related.

[0002]

2. Description of the Related Art In recent years, with the development of multimedia applications, it has become common to uniformly handle information of all media such as images, voices and texts. At this time, it becomes possible to handle media in a unified manner by digitizing all media. However, since a digitized image has a huge amount of data, an image information compression technique is indispensable for storage and transmission. On the other hand, standardization of compression technology is also important in order to interoperate compressed image data. Image compression technology standards include ITU (International Telecommunication Union Telecommunication Standardization Sector) H.261, H.263, and ISO (International Organization for Standardization) MPEG (Moving Picture Experts Gro).
up) -1, MPEG-2, MPEG-4 and so on.

In an image coding system such as MPEG, a specific bit string called a start code is added to the beginning of a frame or slice of a coded signal. The start code is useful information indicating from which position of the coded signal the image decoding apparatus can start decoding, and is used to restore decoding at the start of reproduction or when an unrecoverable error occurs in the coded signal. Here, start decoding like the start code
A specific bit string used for synchronization of return is called a synchronization pattern. By the way, in order to synchronize correctly,
It is important that the bit string of the sync pattern does not appear in the encoded signal except where the sync pattern should be. In MPEG, a variable length coding code used for coding is designed so that a synchronization pattern does not appear at a position other than a predetermined position such as the beginning of a frame / slice. On the other hand, in the case of an image coding method using arithmetic coding, if the result of arithmetic coding is that the same bit string as the synchronization pattern appears, delimiter bits are inserted into the coded signal to form the same bit string as the synchronization pattern. In many cases, it is prevented. For example, in H.263, a start code in which 15 or more 0-valued bits are consecutive is defined. When arithmetic coding is used, when 14 consecutive 0-valued bits appear, the start code immediately follows 1 Value bits are inserted so that 15 or more 0 value bits do not appear consecutively.

In the specification, a device for converting a coded signal so that the sync pattern does not appear in the coded signal is called a sync pattern removing device. On the contrary, a device for returning the encoded signal converted so that the sync pattern does not appear is called a sync pattern insertion device.

FIG. 14 shows a conventional sync pattern removing device 2.
It is a block diagram which shows the structure of 00a. First, the synchronization pattern removing device receives an image signal Img from the outside and encodes it by the image encoding means ImgEnc to generate an encoded signal BitStrm21. The zero-value bit counting means ZeroBitC counts the number of consecutive zero-valued bits in the encoded signal BitStrm21, and when the number exceeds the prescribed number, it notifies the delimiter bit insertion instructing means BitI by the signal FindZeroBits. The delimiter bit insertion instruction means BitI switches the switch SW01 to the 1 side when the number of 0-valued bits exceeds a prescribed number, and inserts a 1-valued bit as a delimiter bit. The multiplexing means Mux01 multiplexes other data such as voice into a transmission format and outputs it as a coded signal BitStrm02.

FIG. 15 shows a conventional sync pattern insertion device 2.
It is a block diagram which shows the structure of 00b. The device is shown in FIG.
Coded signal BitStr output from the synchronization pattern removal device of No. 4
It inputs m02 and decrypts it. The separation means Demux01
The encoded signal BitStrm02 is separated and the encoded signal BitStrm03 including the delimiter bit is output. Zero value bit counting means ZeroBitC is a sequence of zeros in the encoded signal BitStrm21.
When the number of value bits is counted and exceeds a prescribed number (the same value as the number of consecutive 0 value bits of the delimiter bit insertion condition of the synchronization pattern removal device), this is signaled to the delimiter bit removal instruction means BitI by the signal FindZeroBits. Notice. Delimiter bit removal instruction means BitI is a place where a delimiter bit is included,
The switch R02 is switched to the 1 side by the signal RmvBit to remove the delimiter bit. The image decoding means ImgDec decodes the encoded signal BitStrm04 from which the delimiter bits have been removed, and outputs it as an image signal DecImg.

[0007]

However, the conventional sync pattern removal / insertion is a bit-unit data operation, and bit-unit data insertion / deletion involves bit processing. For example, when deleting a 1-bit delimiter bit from a coded signal, bit-based arithmetic processing such as bit shift is required for all coded signals that follow the delimiter bit, and the amount of processing required for conversion is reduced. There is a problem that it becomes large.

In order to solve these problems, the present invention introduces a byte-unit delimiter signal so as to easily delete the same bit string as the sync pattern from the coded signal. It is intended to provide a pattern removal method.

[0009]

[Means for Solving the Problems] First invention (Claim 1)
When a bit string that matches the synchronization pattern is detected at a position other than the place where the synchronization pattern originally exists in the encoded signal, is before the last bit in the bit string that matches the synchronization pattern and at the end of the bit string. Is a method for removing a synchronization pattern by inserting a predetermined byte sequence whose insertion result does not become a synchronization pattern at the byte boundary of.

A second aspect of the present invention (claim 2) is a result of removing a sync pattern by inserting a predetermined byte string into a bit string that coincides with the sync pattern at a position other than where the sync pattern originally exists in the encoded signal. The encoded signal is input, the predetermined byte sequence starting from the position of the byte boundary is included, and the bit sequence that matches the synchronization pattern is present at the position resulting from the removal of the predetermined byte sequence from the encoded signal. In this case, the synchronization pattern insertion method is characterized in that the predetermined byte string is removed from the encoded signal and a synchronization pattern is inserted.

According to a third aspect of the present invention (claim 3), when a bit string that matches the sync pattern is detected in a coded signal other than the place where the sync pattern originally exists, the last bit string that matches the sync pattern is detected. Before the bit, and
At the last byte boundary in the bit string, a predetermined byte string whose insertion result does not become a sync pattern is inserted to remove the sync pattern, and the predetermined byte string is inserted, and the sync signal is synchronized at a predetermined position with respect to the encoded signal. It is a method of removing a synchronization pattern, which is characterized by inserting a pattern.

According to a fourth aspect of the present invention (claim 4), a predetermined byte string is inserted into a bit string that coincides with the sync pattern in a coded signal except where the sync pattern originally exists, and the sync pattern is removed. A coded signal with a sync pattern inserted at a predetermined position for the result is input, the sync pattern is removed from the predetermined position of the coded signal, and the predetermined byte string starting from a byte boundary position is included, and If there is a bit string that matches the synchronization pattern at the position resulting from the removal of the predetermined byte sequence from the encoded signal, the predetermined byte sequence is removed from the encoded signal and the predetermined byte sequence is removed. And outputs a coded signal as a result of inserting the synchronization pattern.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram showing a configuration of a synchronization pattern removing apparatus 101 (corresponding to claim 1) according to an embodiment of the present invention. Units that operate in the same manner as those in the block diagram of FIG. 14 and signals that operate in the same manner are denoted by the same symbols, and description thereof is omitted.

The buffer Buf1 is a buffer for temporarily storing the coded signal BitStrm10 output by the image coding means ImgEnc for detecting a synchronization pattern. When the sync pattern detecting means SyncF1 detects a bit string that matches the sync pattern in the encoded signal, the sync pattern detecting means SyncF1
Notifies the byte boundary detection means BAlignF that the sync pattern has been detected by the signal FindSync. The encoded signal BitStrm11 that has undergone the synchronization pattern detection processing is stored in the buffer Buf1.
To output as a coded signal BitStrm11. When notified that the sync pattern has been detected, the byte boundary detection means BAlignF detects the last byte boundary in the bit string that is before the last bit in the bit string that matches the sync pattern in the encoded signal BitStrm11 and in the bit string. To do. The byte boundary detecting means BAlignF detects the signal Ins when the byte boundary is detected.
Switch SW1 to 1 side by Deli, delimiter byte
Deli is inserted into the encoded signal BitStrm11 and output as BitStrm13. After inserting the delimiter byte, the switch SW1 is switched to the 0 side. When there is no notification from the synchronization pattern detection means SyncF1, the switch SW1 is set to the 0 side and the encoded signal Bit
Strm11 is output as BitStrm13 as it is. The multiplexing means Mux1 multiplexes the coded signal BitStrm13 into a transmission format together with other data such as voice and encodes the coded signal BitStrm13.
Output as m14.

FIG. 2 is a conceptual diagram of synchronization pattern detection and delimiter byte insertion processing. Here, the synchronization pattern Sync
Is a bit string consisting of 23-bit 0 and 1-bit 1. The delimiter byte Deli1 is 1 byte and all bit values are 1. Sync pattern detecting means SyncF1 is a coded signal BitS
For trm12, check whether there is a bit string that matches the sync pattern other than the place where the sync pattern should originally exist. The synchronization pattern is detected by, for example, checking whether or not each bit of the encoded signal and the synchronization pattern match. In the case of the coded signal BS1 of FIG. 2, the synchronization pattern Sync is detected at the rectangular position of SyncMatch. At this time, the delimiter byte Deli is inserted at the byte boundary closest to the end of the bit string before the last bit of the bit string that matches the synchronization pattern Sync. In the case of the coded signal BS1 of FIG. 2, I
Insert the delimiter byte Deli at the position of nsPos. The coded signal BS2 of FIG. 2 is a delimiter byte De for the coded signal BS1.
li shows the coded signal resulting from the insertion. In this way, the size of the delimiter data is set in bytes and the insertion position of the delimiter data is set at the byte boundary, so that the synchronization pattern removal processing can be reduced compared to the insertion of the delimiter data in bit units, and the processing load is reduced. be able to. Also,
Since the delimiter data is 1 byte, the amount of data that must be inserted is increased compared to the insertion of 1-bit delimiter data, but since a bit string that is unlikely to appear in the encoded signal is used for the synchronization pattern, The decrease in encoding efficiency due to the delimiter data being 1 byte is almost negligible.

As described above, the sync pattern removing device of the present invention can handle delimiter data in byte units, and can reduce the processing load as compared with inserting delimiter data in bit units.

The value used as the delimiter byte Deli may be other than the value shown in the present embodiment, but any bit string that can be taken by the combination of the sync pattern and the inserted delimiter byte does not become the bit string of the sync pattern. Must be a value.

(Embodiment 2) FIG. 3 is a block diagram showing the configuration of a synchronization pattern insertion device 102 (corresponding to claim 2) according to Embodiment 2 of the present invention. In FIG.
Units that perform the same operations as those in the block diagram of FIG. 15 and signals that have the same operations are denoted by the same symbols, and description thereof is omitted. The synchronization pattern insertion device of the present embodiment, for example,
Like the coded signal created in the first embodiment, a predetermined byte string is inserted into a bit string that matches the sync pattern at a position other than the position where the sync pattern originally exists in the coded signal, and the sync pattern is removed. It can be used to decode the resulting encoded signal.

The demultiplexing means Demux1 separates the coded signal BitStrm20 multiplexed into a coded signal bitStrm21 including delimiter bytes.
To separate. The buffer Buf2 is a buffer that temporarily stores the encoded signal BitStrm21 output by the separating unit Demux1 for detecting a delimiter byte. Delimiter byte / sync pattern detection means DeliF is the encoded signal B in the buffer Buf2.
For itStrm23, a sync pattern including delimiter bytes is detected. Delimiter byte / sync pattern detection means Deli
F is a delimiter byte removal instruction means by the signal FindDeli when a sync pattern including a delimiter byte is detected.
Notify DeliR. Delimiter byte removal instruction means DeliR
When it is notified that the sync pattern has been detected, the switch opens the switch SW2 by the signal RmvDeli and removes the delimiter byte data. The image decoding means ImgDec decodes the encoded signal BitStrm24 resulting from removing the delimiter byte and outputs it as a decoded image DImg.

The operation of removing the delimiter byte according to the present invention will be described with reference to FIG. It is assumed that the coded signal BS2 is input as the coded signal including the delimiter byte. The detection of the synchronization pattern including the delimiter byte can be performed, for example, by first detecting the delimiter byte and then checking whether or not the bit string excluding the delimiter byte includes the synchronization pattern. In the case of the coded signal BS2 of FIG. 2, the synchronization pattern including the delimiter pattern is checked by checking whether the byte string Bn-2, Bn-1, Bn, Bn + 2 in which the delimiter byte of Bn + 1 is removed includes the synchronization pattern. Can be detected. To remove the delimiter byte detected from the encoded signal BS2, the byte data Bn + 1 including the delimiter byte may be deleted from the encoded signal.

As described above, the sync pattern insertion device of the present invention can handle delimiter data in units of bytes, and can reduce the processing load as compared with the case of deleting delimiter data in units of bit.

(Third Embodiment) FIG. 4 shows the third embodiment.
4 is a block diagram showing a configuration of a synchronization pattern removing device 103 (corresponding to claim 3) according to FIG. In FIG. 5, units that perform the same operations as those in the block diagram of FIG. 1 and signals that have the same operations are denoted by the same symbols, and description thereof will be omitted.

The synchronization pattern removing apparatus according to the third embodiment differs from the synchronization pattern removing method according to the first embodiment in that a synchronization pattern insertion process is performed on a coded signal in which delimiter bytes are inserted.

Depending on the image encoding method, the encoded signal may not include the synchronization pattern. On the other hand, for example, M
There is also a multiplexing method designed on the assumption that a start code (synchronization pattern) is included in an image coded signal like a PEG-2 program stream. When an image coded signal that does not include a synchronization pattern is multiplexed in such a multiplexing method, the synchronization pattern removal method shown in the first embodiment is performed before the image coded signal is multiplexed, and the result is obtained. A synchronization pattern may be inserted for

Coded signal BitStr with delimiter bytes inserted
The processing up to the output of m13 is the same as that of the synchronization pattern removing apparatus of the first embodiment. For the encoded signal BitStrm13, the synchronization pattern insertion instructing means SyncI switches the switch SW3 to the 1 side and inserts the synchronization pattern Sync at the position where the synchronization pattern should be inserted. For example, the synchronization pattern can be inserted immediately before the frame slice of the coded image signal, and the start position of the frame slice in the coded signal is synchronized with the sync position information SyncPo from the image coding means ImgEnc.
By s, the image coding means ImgEnc is inserted into the synchronization pattern insertion instructing means SyncI. The multiplexing means Mux2 multiplexes the coded signal BitStrm15 after inserting the synchronization pattern Sync,
Output as encoded signal BitStrm16.

FIG. 5 is a conceptual diagram showing a coded signal with a sync pattern inserted. Coded signal BS51 shows a coded signal before the sync pattern is inserted, and coded signal BS52 shows a coded signal after the sync pattern is inserted. In this example, the synchronization signal Sync is inserted immediately before the frame or slice of the encoded signal BS51.

As described above, the synchronization pattern removing apparatus of the present invention inserts a synchronization pattern into a coded signal in which delimiter bytes are inserted and multiplexes the coded signal, so that the coded signal requires a sync pattern. It is possible to multiplex a coded signal that does not include a synchronization pattern in the system.

(Embodiment 4) FIG. 6 is a block diagram showing the structure of a synchronization pattern insertion device 104 (corresponding to claim 4) according to Embodiment 4 of the present invention. In FIG.
Units that perform the same operations as those in the block diagram in FIG.
The sync pattern insertion device of the present embodiment inserts a predetermined byte string and removes the same bit string as the sync pattern from the coded signal, such as the coded signal created in the third embodiment. On the other hand, it can be used for decoding an encoded signal in which a synchronization pattern is inserted at a predetermined position.

The separating means Demux2 separates the multiplexed coded signal BitStrm30 into coded signals BitStrm31 including a synchronization pattern. The buffer Buf3 is a separation means Dem
This is a buffer that temporarily stores the coded signal BitStrm31 output by ux2 for detecting a synchronization pattern. The sync pattern detection means SyncF2 detects a sync pattern for the coded signal BitStrm33 accumulated in the buffer Buf3. When the sync pattern detecting means SyncF2 detects the sync pattern, the sync pattern detecting means SyncF2 receives the sync pattern removing means Sy by the signal FindSync.
Notify ncR. When notified of the detection of the synchronization pattern, the synchronization pattern removal means SyncR opens the switch SW4 by the signal RmvSync and removes the synchronization pattern.
Subsequent processing on the encoded signal BitStrm21 from which the synchronization pattern is removed is the same as that of the synchronization pattern insertion device of the second embodiment.

As described above, the sync pattern insertion device of the present invention makes it possible to decode a coded signal in which a sync pattern is inserted into a coded signal in which delimiter bytes are inserted and multiplexed.

(Fifth Embodiment) FIG. 7 is a block diagram showing the structure of a synchronization pattern removing apparatus 105 (corresponding to claim 5) according to a fifth embodiment of the present invention. In FIG.
Units that perform the same operations as those in the block diagram of FIG. 1 and signals that have the same operations are denoted by the same symbols, and description thereof will be omitted.

The synchronization pattern used in this embodiment is a bit string including consecutive 0-valued bits like the synchronization pattern Sync in FIG. When the sync pattern includes consecutive 0-bits of N bits, no matter where the sync pattern exists in the bit string, at least M consecutive bytes from the byte boundary (M is (N-7) is 8 Quotient divided by)
It is possible to detect a pattern in which the bit value is 0. Therefore, in order to find a bit string that matches the synchronization pattern of FIG. 2 in the encoded signal, the encoded signal is input for each byte, and only when two consecutive 0s in the input byte sequence are detected, It suffices to check whether that portion matches the synchronization pattern. Compressed data such as image coded signals is 0,
Since there is little statistical bias in the appearance frequency of 1s, it is rare that 0s continue for 2 bytes. Therefore, in most cases, it suffices to check whether two 0's continue in the byte string, and the amount of processing required to detect the synchronization pattern can be reduced. FIG. 8 is a processing flow showing the flow of the synchronization pattern detection and delimiter byte insertion processing. Bn is the n-th byte data of the encoded signal (n = 0 indicates the first byte of the encoded signal), and L is the total number of bytes of the encoded signal. It is judged whether the continuous 2-byte data is 0 (process F82), and if so,
Furthermore, it is determined whether a synchronization pattern is included (process F8
Four). If the synchronization pattern is included, a delimiter byte is inserted after Bn (process F85). The above process is repeated for each byte of the coded signal, and when n = L and all bytes of the coded signal are input, the process ends (process F87).

The synchronous pattern removing apparatus of FIG. 7 performs the processing of the above flow. The byte input means ByteInput inputs the encoded signal BitStrm10 in byte units. Buffer Buf4
Temporarily stores the input coded signal BitStrm70 in byte units for detecting a synchronization pattern. The zero-value byte counter ZeroC counts consecutive zero-value bytes in the encoded signal BitStrm71. Zero value byte number counter ZeroC is 0
When two value bytes continue, the signal FindZero notifies the sync pattern detecting means FSync2. The sync pattern detecting means FSync2 checks whether or not two consecutive zero-value bytes and the bytes before and after the byte contain a bit string of the sync pattern. When the synchronization pattern is detected, the delimiter byte Deli is inserted into the encoded signal BitStrm11 by the same processing as that of the first embodiment.

As described above, the sync pattern removing apparatus of the present invention can reduce the processing load for detecting the bit string that matches the sync pattern.

In this embodiment, the case where 0s are continuous in the bit string of the synchronization pattern has been described, but the same idea can be applied to the case where 1s are continuous in the bit string of the synchronization pattern.

(Sixth Embodiment) FIG. 9 is a block diagram showing the structure of a synchronization pattern insertion device 106 (corresponding to claim 6) according to the sixth embodiment of the present invention. In FIG.
Units that perform the same operations as those in the block diagram in FIG.

The synchronization pattern insertion device of this embodiment is
For example, as in the coded signal created in the second embodiment, a predetermined byte string is inserted into a bit string that matches the sync pattern at a position other than where the sync pattern originally exists in the coded signal, and the sync pattern is created. It can be used for decoding the encoded signal resulting from the removal.

FIG. 10 is a processing flow showing the flow of the synchronization pattern detection including the delimiter byte and the delimiter byte removal processing. Bn is the nth byte data of the encoded signal (n = 0
Indicates the first byte of the encoded signal), and L is the total number of bytes of the encoded signal. It is determined whether consecutive 2 bytes of data are 0 (processing F102), and if so, it is determined whether the byte following the 2 bytes of 0 matches the delimiter byte (processing F1).
03). If it matches the delimiter byte, it is further determined whether a sync pattern is included (process F104). If the synchronization pattern is included, the delimiter byte is removed (process F105). The above process is repeated for each byte of the coded signal, and when n = L and all bytes of the coded signal are input, the process ends (process F107).

The synchronization pattern insertion device of FIG. 9 performs the processing of the above flow. The byte input means ByteInput inputs the encoded signal BitStrm21 in byte units. Buffer Buf5
Stores the input coded signal BitStrm90 in byte units temporarily for the synchronization pattern detection. The zero-value byte counter ZeroC counts consecutive zero-value bytes in the encoded signal BitStrm91. Zero value byte number counter ZeroC is 0
If two value bytes are consecutive, the signal FindZero causes
Notify the delimiter byte / sync pattern detection means FSync2. Delimiter byte / sync pattern detection means FSync2 is 0
Check whether the bit string of the synchronization pattern including the delimiter byte is included in the place where two value bytes are consecutive and the bytes before and after it. When the synchronization pattern including the delimiter byte is detected, the delimiter byte Deli is removed from the encoded signal BitStrm22 by the same process as in the second embodiment.

As described above, the sync pattern insertion device of the present invention can reduce the processing load for detecting a bit string that matches a sync pattern including delimiter bytes.

In this embodiment, the case where 0s are continuous in the bit string of the synchronization pattern has been described, but the same idea can be applied to the case where 1s are continuous in the bit string of the synchronization pattern.

(Seventh Embodiment) FIG. 11 shows a synchronization pattern removing apparatus 107 according to a seventh embodiment of the present invention (claim 7).
Is a block diagram showing the configuration of (corresponding to). In FIG. 11, units that perform the same operations as those in the block diagrams in FIGS. 7 and 4 and signals that perform the same operations are denoted by the same symbols, and description thereof will be omitted.

For the reason shown in the third embodiment, it may be necessary to insert the synchronization pattern in the encoded signal in which the delimiter byte is inserted. In the seventh embodiment, similar to the third embodiment, a synchronization pattern insertion process is performed on a coded signal in which delimiter bytes are inserted. In particular,
Coded signal BitS generated by the same processing as in the fifth embodiment
The same sync pattern insertion processing as in the third embodiment is performed on trm13.

As described above, the sync pattern removing apparatus of the present invention can reduce the processing load for detecting a bit string that matches a sync pattern including delimiter bytes.

In this embodiment, the case where 0s are continuous in the bit string of the synchronization pattern has been described, but the same idea can be applied to the case where 1s are continuous in the bit string of the synchronization pattern.

(Embodiment 8) FIG. 12 shows a synchronization pattern insertion device 108 (claim 8) according to Embodiment 8 of the present invention.
Is a block diagram showing the configuration of (corresponding to). In FIG. 12, units that perform the same operations as those in the block diagrams of FIGS. 9 and 6 and signals of the same operations are denoted by the same symbols, and description thereof will be omitted. The sync pattern insertion device of the present embodiment inserts a predetermined byte string and removes the same bit string as the sync pattern from the coded signal, such as the coded signal created in the third embodiment. On the other hand, it can be used for decoding an encoded signal in which a synchronization pattern is inserted at a predetermined position.

Like the fourth embodiment, the eighth embodiment removes the sync pattern and the delimiter byte from the coded signal in which the sync pattern is inserted in the coded signal in which the delimiter byte is inserted. Specifically, the fourth embodiment
Coded signal Bi with the synchronization pattern removed by the same processing as
For tStrm21, the same synchronization pattern removal processing as in the sixth embodiment is performed.

As described above, the sync pattern insertion device of the present invention can reduce the processing load for detecting a bit string that matches a sync pattern including delimiter bytes.

In this embodiment, the case where 0s are continuous in the bit string of the synchronization pattern has been described, but the same idea can be applied to the case where 1s are continuous in the bit string of the synchronization pattern.

(Ninth Embodiment) Further, a program for realizing the structure of the synchronous pattern removing method or the synchronous pattern inserting method shown in each of the above embodiments is recorded in a storage medium such as a flexible disk. This makes it possible to easily carry out the processing shown in each of the above-described embodiments in an independent computer system.

FIG. 13 is an explanatory diagram of a case where a flexible disk storing the synchronous pattern removing method or the synchronous pattern inserting method of the above-described first to eighth embodiments is used to carry out by a computer system.

FIG. 13B shows the appearance, sectional structure, and flexible disk of the flexible disk as viewed from the front, and FIG. 6A shows an example of the physical format of the flexible disk, which is the recording medium body. . The flexible disk FD is built in a case F, and a plurality of tracks Tr are formed concentrically from the outer circumference to the inner circumference on the surface of the flexible disk FD, and each track is angularly divided into 16 sectors Se. ing. Therefore, in the flexible disk storing the above program, in the area allocated on the flexible disk FD,
An image encoding method as the above program is recorded.

FIG. 13C shows a structure for recording / reproducing the above program on / from the flexible disk FD. When the program is recorded on the flexible disk FD, the image encoding method or the image decoding method as the program is written from the computer system Cs via the flexible disk drive FDD. Further, when the image coding method is constructed in the computer system by the program in the flexible disk, the program is read from the flexible disk by the flexible disk drive and transferred to the computer system.

In the above description, the flexible disk is used as the recording medium, but the same can be applied by using the optical disk. Further, the recording medium is not limited to this, and any recording medium such as an IC card and a ROM cassette that can record the program can be similarly used.

[0055]

As described above in detail, according to the sync pattern removing method / sync pattern inserting method of the present invention,
The removal / insertion of the sync pattern from the coded signal can be realized with a smaller processing amount than the conventional method of inserting the delimiter data in bit units, which is highly effective in speeding up the removal / insertion process of the sync pattern. Can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a synchronization pattern removing device according to a first embodiment.

FIG. 2 is a conceptual diagram of synchronization pattern detection / removal processing according to the first embodiment.

FIG. 3 is a block diagram showing a synchronization pattern insertion device according to a second embodiment.

FIG. 4 is a block diagram showing a synchronization pattern removing device according to a third embodiment.

FIG. 5 is a conceptual diagram showing an encoded signal according to the third embodiment.

FIG. 6 is a block diagram showing a synchronization pattern insertion device according to a fourth embodiment.

FIG. 7 is a block diagram showing a synchronization pattern removing device according to a fifth embodiment.

FIG. 8 is a processing flow chart of synchronization pattern detection / removal processing according to the fifth embodiment.

FIG. 9 is a block diagram showing a synchronization pattern insertion device according to a sixth embodiment.

FIG. 10 is a processing flowchart of delimiter byte and synchronization pattern detection and delimiter byte removal processing according to the sixth embodiment.

FIG. 11 is a block diagram showing a synchronization pattern removing device according to a seventh embodiment.

FIG. 12 is a block diagram showing a synchronization pattern insertion device according to an eighth embodiment.

FIG. 13 is an explanatory diagram of a storage medium for storing a program for realizing the synchronization pattern removing method and the synchronization pattern inserting method of the first to eighth embodiments by a computer system.

FIG. 14 is a block diagram showing a conventional synchronization pattern removing device.

FIG. 15 is a block diagram showing a conventional synchronization pattern insertion device.

[Explanation of symbols]

Img Image signal ImgEnc Image coding means Buf1, Buf2, Buf3, Buf4, Buf5 Buffer BitStrm10, BitStrm11, BitStrm13, BitStrm14, BitStr
m15, BitStrm16, BitStrm20, BitStrm21, BitStrm22, B
itStrm23, BitStrm24, BitStrm30, BitStrm31, BitStrm3
2, BitStrm70, BitStrm71, BitStrm90, BitStrm91, Bit
Strm01, BitStrm02, BitStrm03, BS1, BS2, BS51, BS52
Encoded signal SyncF1, SyncF2 Sync pattern detection means FindSync, RmvSync, FindDeli, InsDeli, RmvDeli, Fin
dZero, FindeZeroBits, InsBit, RmvBit Notification / instruction signal BAlignF Byte boundary detection means SW1, SW2, SW3, SW4, SW01, SW02 Switch Deli Delimiter byte Mux1, Mux2 Multiplexing means Sync Sync pattern InsPos Delimiter byte inserting location Demux1, Demux2 Separating means DeliF, DeliF2 Delimiter byte / sync pattern detection means DeliR Delimiter byte removal means ImgDec Image decoding means DImg Decoded image SyncI Sync pattern insertion instruction means Frm Frame / slice SyncR Sync pattern removal means ByteInput Byte input means ZeroC 0 value Byte counter ZeroBitC Zero value bit Counting means BitI Delimiter bit insertion instruction means Bit Delimiter bit BitR Delimiter bit removal instruction means F81 to F87, F101 to F107 Processing items of flow chart Cs Computer system FD Flexible disk FDD Flexible disk drive

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshinori Matsui             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Toshishi Kondo             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Kiyoshi Abe             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5C059 MA00 RB10 RC02 RE01 SS20                       UA34                 5C063 AB03 AB05 AC01 AC05 AC10                       CA11 CA14 CA23 DA01 DA05                       DA07 DA13                 5K028 EE07 KK13 MM16 NN05                 5K047 AA02 DD01 DD02 HH01 HH12                       HH45

Claims (12)

[Claims] 1. When a bit string that matches a sync pattern is detected in a coded signal other than the place where the sync pattern originally exists, before the last bit in the bit string that matches the sync pattern, and in the bit string. A synchronization pattern removal method characterized by inserting a predetermined byte sequence whose insertion result does not become a synchronization pattern at the last byte boundary of, and removing the synchronization pattern. 2. A coded signal as a result of inserting a predetermined byte string into a bit string that coincides with a sync pattern at a position other than where the sync pattern originally exists in the coded signal and removing the sync pattern, and inputting the byte. If the bit string that includes the predetermined byte string starting from the boundary position and that coincides with the synchronization pattern exists at the position resulting from the removal of the predetermined byte string from the encoded signal, the predetermined byte string is A synchronization pattern insertion method, characterized in that the synchronization pattern is inserted by removing it from the encoded signal. 3. When a bit string matching the sync pattern is detected in a coded signal other than the place where the sync pattern originally exists, before the last bit in the bit string matching the sync pattern and in the bit string. At the last byte boundary of the, a predetermined byte string whose insertion result does not become a sync pattern is inserted, the sync pattern is removed, and a sync pattern is placed at a predetermined position with respect to the encoded signal resulting from the insertion of the predetermined byte string. A method for removing a sync pattern, characterized in that 4. A sync pattern at a predetermined position with respect to a result of removing a sync pattern by inserting a predetermined byte string into a bit string that matches the sync pattern at a position other than the place where the sync pattern originally exists in the encoded signal. Is input, the sync pattern is removed from a predetermined position of the coded signal, and the predetermined byte sequence starting from a byte boundary position is included, and the predetermined byte sequence is encoded signal. When there is a bit string that coincides with the sync pattern at the position resulting from the removal from the inside, the predetermined byte string is removed from the encoded signal, the predetermined byte string is removed, and the result of inserting the sync pattern A synchronization pattern insertion method characterized by outputting an encoded signal. 5. The synchronization pattern removing method according to claim 1, wherein a synchronization pattern including N bit values 0 consecutive in a bit string is used and M consecutive from a byte boundary in the encoded signal.
All bit values of bytes (M is a quotient of (N-7) divided by 8) are all 0
In the case of, the sync pattern removal method is characterized in that the sync pattern is detected by checking whether or not the bit string consisting of M bytes continuous with the byte data before and after the byte position includes the bit string of the sync pattern. 6. The synchronization pattern insertion method according to claim 2, wherein a synchronization pattern including N bit values 0 consecutive in a bit string is used, and M consecutive from a byte boundary in the encoded signal.
All bit values of bytes (M is a quotient of (N-7) divided by 8) are all 0
Only in the case of, the sync pattern insertion method is characterized in that the sync pattern is detected by checking whether or not the bit string consisting of M bytes continuous with the byte data before and after the byte position includes the bit string of the sync pattern. 7. The synchronization pattern removing method according to claim 3, wherein a synchronization pattern including N bit values 0 consecutive in a bit string is used and M consecutive from a byte boundary in the encoded signal.
All bit values of bytes (M is a quotient of (N-7) divided by 8) are all 0
In the case of, the sync pattern removal method is characterized in that the sync pattern is detected by checking whether or not the bit string consisting of M bytes continuous with the byte data before and after the byte position includes the bit string of the sync pattern. 8. The synchronization pattern insertion method according to claim 4, wherein a synchronization pattern including N bit values 0 consecutive in a bit string is used, and M consecutive from a byte boundary in a coded signal is used.
All bit values of bytes (M is a quotient of (N-7) divided by 8) are all 0
Only in the case of, the sync pattern insertion method is characterized in that the sync pattern is detected by checking whether or not the bit string consisting of M bytes continuous with the byte data before and after the byte position includes the bit string of the sync pattern. 9. A storage medium for storing a program for performing a synchronization pattern removal method by a computer, wherein the program matches the synchronization pattern in a computer except where the synchronization pattern originally exists in the encoded signal. When a bit string to be detected is detected, a predetermined byte string whose insertion result does not become a synchronization pattern is inserted before the last bit in the bit string that matches the synchronization pattern and at the last byte boundary in the bit string. A storage medium characterized in that the characteristic synchronization pattern removing method is performed. 10. A storage medium that stores a program for performing an image encoding method by a computer,
The above program inputs a coded signal as a result of removing a sync pattern by inserting a predetermined byte string into a bit string that matches the sync pattern at a position other than where the sync pattern originally exists in the coded signal, The predetermined byte sequence is encoded when including the predetermined byte sequence starting from the position of the byte boundary, and when there is a bit sequence that matches the synchronization pattern at the position resulting from the removal of the predetermined byte sequence from encoding. A storage medium characterized by causing a synchronization pattern insertion method characterized by removing the synchronization signal from the encoded signal. 11. A storage medium storing a program for performing an image encoding method by a computer,
The above program causes the computer to detect a bit string that matches the sync pattern at a position other than the place where the sync pattern originally exists in the encoded signal, before the last bit in the bit string that matches the sync pattern, and the bit string. A predetermined byte sequence whose insertion result does not become a synchronization pattern is inserted at the last byte boundary in the inside, and a synchronization pattern is inserted at a predetermined position with respect to the encoded signal resulting from the insertion of the predetermined byte sequence. And a method for removing a synchronization pattern. 12. A storage medium storing a program for performing an image encoding method by a computer,
The above program synchronizes to the computer at a predetermined position with respect to the result of removing the sync pattern by inserting a predetermined byte string into a bit string that matches the sync pattern at a position other than where the sync pattern originally exists in the encoded signal. A coded signal with a pattern inserted is input, a sync pattern is removed from a predetermined position of the coded signal, the predetermined byte sequence starting from a byte boundary position is included, and the predetermined byte sequence is being encoded. When there is a bit string that coincides with the synchronization pattern at the position resulting from the removal from the predetermined byte sequence, the predetermined byte sequence is removed from the encoded signal, and the encoded signal obtained as a result of removing the predetermined byte sequence is output. And a synchronization pattern inserting method.