Coding system and decoding system

• US 7,472,316 B2
• Filed: 10/23/2006
• Issued: 12/30/2008
• Est. Priority Date: 09/29/1995
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Watanabe, Toshiaki, Chujoh, Takeshi, Kikuchi, Yoshihiro, Nagai, Takeshi, Dachiku, Kenshi
• Primary Examiner(s): Baker; Stephen M
• Application Number:
  US11/584,548
• Publication Number:
  US 20070094576A1
• Time in Patent Office: 799 Days
• Field of Search: 714/701
• US Class Current: 714/701
• CPC Class Codes: G11B 20/1813 by adding special bits or symbols to the coded information G11B20/1809 takes precedence
• CPC Class Codes: G11B 27/3027 used signal is digitally coded
• CPC Class Codes: H03M 13/15 Cyclic codes, i.e. cyclic shifts of codewords produce other codewords, e.g. codes defined by a generator polynomial, Bose-Chaudhuri-Hocquenghem [BCH] codes H03M13/17 takes precedence
• CPC Class Codes: H03M 13/152 Bose-Chaudhuri-Hocquenghem [BCH] codes
• CPC Class Codes: H03M 13/23 using convolutional codes, e.g. unit memory codes
• CPC Class Codes: H03M 13/33 Synchronisation based on error coding or decoding
• CPC Class Codes: H03M 13/356 Unequal error protection [UEP]
• CPC Class Codes: H04J 3/0602 Systems characterised by the synchronising information used
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0042 Encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit distortions, jitter, or to improve signal shape H04L1/0067 takes precedence
• CPC Class Codes: H04L 1/0047 Decoding adapted to other signal detection operation in conjunction with sequence estimation or equalization H04L25/03286
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 1/007 Unequal error protection for format H04L1/0078; for codes per se H03M13/35
• CPC Class Codes: H04L 1/0075 Transmission of coding parameters to receiver H04L1/0023 takes precedence
• CPC Class Codes: H04L 1/0079 Formats for control data H04L1/16 takes precedence; training sequences H04L25/00 and H04L27/00
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 2001/0098 Unequal error protection
• CPC Class Codes: H04L 7/041 using special codes as synchronising signal
• CPC Class Codes: H04L 7/048 using the properties of error detecting or error correcting codes, e.g. parity as synchronisation signal
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 19/61 : in combination with predictive coding
• CPC Class Codes: H04N 19/68 : involving the insertion of resynchronisation markers into the bitstream
• CPC Class Codes: H04N 19/70 : characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/89 : involving methods or arrangements for detection of transmission errors at the decoder
• CPC Class Codes: H04N 7/56 : Synchronising systems therefor

Abstract

In a coding system wherein an error correction/detection coding is combined with a synchronization recovering technique using a synchronization code, the problems of a pseudo synchronization and a step out due to error detection are solved. There is provided a coding part 212 for coding an input multiplexed code string 201 to an error correcting/detecting code comprising an information bit and a check bit, and code string assembling part 213 for inserting a synchronization code into any one of a plurality of periodically predetermined synchronization code inserting positions in the code string 201, for arranging the information bit at an optional position in the code string, and for arranging the check bit at a position other than the synchronization code inserting positions in the code string 201 to assemble an output code string 205.

Claims

1. A decoding method, comprising:

detecting a synchronization code at a plurality of synchronization code inserting positions periodically provided in an input code string, the input code string including a multiplexed code string obtained by multiplexing a plurality of variable length code strings, each of the plurality of variable length code strings having a code capable of being decoded in forward and backward directions, the code being generated by compressing and coding an image signal, the input code string having stuffing bits;

demultiplexing the multiplexed code string in the input code string based on a position of the detected synchronization code to generate the variable length code; and

decoding the generated variable length code to output a reproduced image signal.

2. A decoding apparatus, comprising:

a synchronization code detector configured to detect a synchronization code at a plurality of synchronization code inserting positions periodically provided in an input code string, the input code string including a multiplexed code string obtained by multiplexing a plurality of variable length code strings, each of the plurality of variable length code strings having a code capable of being decoded in forward and backward directions, the code being generated by compressing and coding an image signal, the input code string having stuffing bits;

a demultiplexer configured to demultiplex the multiplexed code string in the input code string based on a position of the detected synchronization code to generate the variable length code; and

a decoder configured to decode the generated variable length code to output a reproduced image signal.

3. The decoder according to claim 2, further comprising:

a code string converter configured to convert a code string, except for the synchronization code, into an original code string, each code of the code string being located with a Hamming distance from the synchronization code, the Hamming distance being equal to or more than a predetermined value at the synchronization code inserting position of the input code string.

4. The decoder according to claim 2,

wherein the input code string has a stuffing code and is capable of being uniquely decoded from a backward direction of the input code string, the stuffing code having a Hamming distance from the synchronization code or a portion of the synchronization code to be equal to or more than, a predetermined value.

5. The decoder according to claim 4,

wherein the stuffing code is arranged just before the synchronization code in the input code string.

6. The decoder according to claim 2,

wherein the multiplexed code string is generated by multiplexing the variable length codes in units of one frame of the image signal;

and

the demultiplexer demultiplexes the multiplexed code string in units of one frame.

7. The decoder according to claim 6, further comprising:

a code string converter configured to convert a code string, except for the synchronization code, into an original code string, each code of the code string being located with a Hamming distance from the synchronization code, the Hamming distance being equal to or more than a predetermined value at the synchronization code inserting position of the input code string.

8. The decoder according to claim 2,

wherein the multiplexed code string is generated by multiplexing the variable length codes in units of a partial area of each frame of the image signal;

and

the demultiplexer demultiplexes the multiplexed code string in units of the partial area.

9. The decoder according to claim 8, further comprising:

a code string converter configured to convert a code string, except for the synchronization code, into an original code string, each code of the code string being located with a Hamming distance from the synchronization code, the Hamming distance being equal to or more than a predetermined value at the synchronization code inserting position of the input code string.

10. The decoder according to claim 2,

wherein the multiplexed code string is generated by multiplexing the variable length codes in units of one frame of the image signal;

the synchronization code detector detects the synchronization code at the synchronization code inserting position positioned immediately before or after an end portion in each multiplexed unit multiplexed in units of one frame of the multiplexed code string; and

the demultiplexer demultiplexes the multiplexed code string in units of one frame.

11. The decoder according to claim 10, further comprising:

a code string converter configured to convert a code string except for the synchronization code, into an original code string, each code of the code string being located with a Hamming distance from the synchronization code, the Hamming distance being equal to or more than a predetermined value at the synchronization code inserting position of the input code string.

12. The decoder according to claim 2,

wherein the multiplexed code string is generated by multiplexing the variable length codes in units of a partial area of each frame of the image signal;

the synchronization code detector detects the synchronization code at the synchronization code inserting position positioned immediately before or after an end portion in each multiplexed unit multiplexed in units of the partial area of the multiplexed code string; and

the demultiplexer demultiplexes the multiplexed code string in units of the partial area.

13. The decoder according to claim 12, further comprising:

a code string converter configured to convert a code string, except for the synchronization code, into an original code string, each code of the code string, being located with a Hamming distance from the synchronization code, the Hamming distance being equal to or more than a predetermined value at the synchronization code inserting position of the input code string.