Information encoding method and apparatus, information decoding method and apparatus and recording medium

• US 6,647,063 B1
• Filed: 07/26/1995
• Issued: 11/11/2003
• Est. Priority Date: 07/27/1994
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Oikawa, Yoshiaki
• Primary Examiner(s): Tran, Khai
• Application Number:
  US08/506,726
• Time in Patent Office: 3,030 Days
• Field of Search: 375/342, 375/240, 375/242, 375/122, 375/245, 375/25, 375/354, 375/355, 370/79, 358/133, 358/141
• US Class Current: 375/242
• CPC Class Codes: G10L 19/035 Scalar quantisation

Abstract

A method of encoding information of an input signal using a fixed number of bits for each unit time frame. Part of the encoded information of at least one second frame temporally consecutively or non-consecutively preceding or following a first frame is contained in the encoded information of the first frame. This eliminates fluctuations in the sound quality due to bit surplus/shortage resulting from quantization for achieving efficient encoding and decoding.

Claims

1. A method of encoding information of an input signal using a fixed number of bits for each unit time frame, wherein the improvement resides in that a part of the encoded information of at least one second frame temporarily consecutively or non-consecutively preceding or following the first frame is contained in the encoded information of said first frame, wherein said part comprises a variable number of bits, and the encoded information of said first frame is determined independent of the encoded information of the at least one second frame.

2. The method of claim 1, wherein information indicating said second frame is contained in said part of the encoded information.

3. The method of claim 1, wherein said part of the encoded information is surplus data which would surpass a pre-set fixed number of bits for the second frame if the input signal for the second frame were encoded using a number of bits which would be required for realizing a required quality of decoded signals obtained on decoding the encoded information for the second frame.

4. The method of claim 3, wherein said part of the encoded information is divided and contained in said first frame.

5. The method of claim 4, wherein said part of the encoded information is such data in the absence of which the encoded information of the second frame can at least be decoded.

6. The method of claim 1, wherein the encoded information of plural frames encoded using a number of bits necessary for producing the decoded signals of a required quality is preserved, and wherein, if, when the input signal of each frame is encoded using the necessary number of bits, there is produced surplus data exceeding the fixed number of bits for each frame, said plural frames are searched and said first frame capable of storing the encoded information in which the surplus data can be stored is found, said surplus data being formed in a code string by being contained in the encoded information of the first frame in which the surplus data can be stored.

7. The method of claim 1, wherein the input signal of a frame is encoded using a number of bits required for realizing a required quality of decoded signal, wherein, if, when the input signal of the frame is encoded using the required number of bits, surplus data is produced which surpasses the fixed number of bits of the frame, said surplus data is preserved, and wherein, if the required number of bits is less than the fixed number of bits of the frame, it is judged whether or not preserved surplus data in the past can be stored in the frame, and if the preserved surplus data in the past can be stored, said preserved surplus data is included in the encoding information of the frame and formed into a code string as said part of the encoding information.

26. The method of claim 1, wherein said second frame precedes said first frame.

27. The method of claim 1, wherein said at least one second frame comprises two or more second frames.

8. A method of decoding encoded information in which a code string produced using a fixed number of bits for each unit time frame is decoded, wherein the improvement resides in that

a code string in which a part of the encoded information of at least one second frame temporally consecutively or non-consecutively preceding or following a first frame is contained in the encoded information of said first frame is decoded, wherein said part comprises a variable number of bits, and the encoded information of said first frame is decoded independent of the encoded information of the at least one second frame.

9. The method of claim 8, wherein

if said part of the encoded information represents surplus data exceeding the fixed number of bits of the second frame when a signal of the second frame is encoded using a number of bits required for obtaining a required quality of signal decoded from the encoded information of the second frame, and if a code string in which surplus data of an arbitrary second frame is contained in the encoded information of a first frame temporally posterior to said second frame is to be decoded, the surplus data contained in said first frame is separated and preserved, and wherein

if the surplus data of the second frame is in the surplus data preserved so far, both surplus data are decoded.

10. The method of claim 8, wherein said part of the encoded information is preserved and, if, when preserving said part of the encoded information, a recording capacity for preserving said part of the encoded information is exceeded, a part of the encoded information of a frame older in the preserving sequence or further from a current frame is sequentially erased and a part of the encoded information of the current frame is preserved.

11. The method of claim 8, wherein

if said part of the encoded information represents surplus data exceeding the fixed number of bits of the second frame when a signal of the second frame is encoded using a number of bits required for obtaining a required quality of signal decoded from the encoded information of the second frame, and if a code string in which surplus data of an arbitrary second frame is contained in the encoded information of a first frame temporally previous to said second frame is to be decoded, a code string of a pre-set number of framers is taken out, and

if the surplus data of the second frame is contained in the code string of the pre-set number of frames, said surplus data is also decoded.

28. The method of claim 8, wherein said second frame precedes said first frame.

29. The method of claim 8, wherein said at least one second frame comprises two or more second frames.

12. An apparatus for encoding an input signal to form encoded information using a fixed number of bits for each unit time frame, comprising:

means for separating a part of the encoded information of at least one second frame temporally consecutively or non-consecutively preceding or following a first frame; and

synthesizing means for incorporating said part of the encoded information separated by said separating means into the encoded information of said first frame,

wherein said part comprises a variable number of bits, and the encoded information of said first frame is determined independent of the encoded information of the at least one second frame.

13. The apparatus of claim 12, wherein said separating means incorporates the information representing the second frame in said part of the encoded information.

14. The apparatus of claim 13, wherein said part of the encoded information is surplus data which would surpass a pre-set fixed number of bits for the second frame if the input signal for the second frame were encoded using a number of bits which would be required for realizing a required quality of decoded signals obtained on decoding the encoded information for the second frame.

15. The apparatus of claim 14, wherein said separating means subdivides said part of the encoded information and wherein said synthesizing means incorporates the subdivided portions of said part of the encoded information in a plurality of first frames.

16. The apparatus of claim 15, wherein said part of the encoded information is such data in the absence of which at least the encoded information of the second frame can be decode.

17. The apparatus of claim 12, wherein said synthesizing means comprises:

means for preserving the encoded information of plural frames encoded using a number of bits necessary for producing decoded signals of a required quality;

means for discriminating such first frame among said plural frames preserving the encoded information in which surplus data exceeding the fixed number of bits for each frame can be stored as said part of the encoded information if, when the input signal of each frame is encoded using the necessary number of bits, there is producing such surplus data; and

means for generating a code string comprising the encoding information of a first frame capable of storing the surplus data and the surplus data contained in the first frame.

18. The apparatus of claim 12, further comprising:

encoding means for encoding the input signal of a frame using a number of bits required for realizing a required quality of decoded signal, wherein said synthesizing means has preserving means for preserving surplus data which surpasses the fixed number of bits of the frame if, when the input signal of the frame is encoded using the required number of bits, said surplus data is produced, means for judging whether preserved surplus data in the past can be stored in a frame if the required number of bits is less than the fixed number of bits of the frame, and means for incorporating said surplus data as said part of the encoded information in a frame found to be capable of storing the surplus data for forming a code string.

30. The apparatus of claim 12, wherein said second frame precedes said first frame.

31. The apparatus of claim 12, wherein said at least one second frame comprises two or more second frames.

19. An apparatus for decoding encoded information in which a code string produced using a fixed number of bits for each unit time frame is decoded, wherein the improvement resides in that a code string in which a part of the encoded information of at least one second frame temporally consecutively or non-consecutively preceding or following a first frame is contained in the encoded information of said first frame is decoded, wherein said part comprises a variable number of bits, and the encoded information of said first frame is decoded independent of the encoded information of the at least one second frame.

20. The apparatus of claim 19, comprising:

separating means for separating surplus data contained in said first frame if said part of the encoded information represents surplus data exceeding the fixed number of bits of the second frame when the signal of the second frame is encoded using a number of bits required for obtaining a required quality of signal decoded from the encoded information of the second frame, and if a code string in which surplus data of an arbitrary second frame is contained in the encoded information of a first frame temporally posterior to said second frame is to be decoded,

means for preserving the separated surplus data,

synthesizing means for synthesizing surplus data of said second frame, if any, present in the sure plus data preserved thus far, and

decoding means for decoding the synthesized encoded information.

21. The apparatus of claim 19, comprising preservation control means for controlling said means for preserving, wherein, if a recording capacity for holding said part of the encoded information is exceeded when preserving said part of the encoded information, a part of the encoded information of a frame older in a preserving sequence or further from a current frame is sequentially erased and a part of the encoded information of the current frame is preserved.

22. The apparatus of claim 19, comprising:

means for taking out a code string of a pre-set number of frames if said part of the encoded information represents surplus data exceeding the fixed number of bits of the second frame when the signal of the second frame is encoded using a number of bits required for obtaining a required quality of signal decoded from the encoded information of the second frame, and if a code string in which surplus data of an arbitrary second frame is contained in the encoded information of a first frame temporally previous to said second frame is to be decoded;

synthesizing means for synthesizing surplus data of said second frame, if any, present in the code string of the pre-set number of frames; and

decoding means for decoding the synthesized encoded information.

32. The apparatus of claim 19, wherein said second frame precedes said first frame.

33. The apparatus of claim 19, wherein said at least one second frame comprises two or more second frames.

23. A recording medium for encoding information encoded from an input signal using a fixed number of bits for each unit time frame, wherein the improvement resides in that

a code string in which a part of the encoded information of at least one second frame temporally consecutively or non-consecutively preceding or following a first frame is contained in the encoded information of said first frame is recorded thereon, wherein said part comprises a variable number of bits, and the encoded information of said first frame is determined independent of the encoded information of the at least one second frame.

24. The recording medium as claimed in claim 23, wherein said code string comprises surplus data which would surpass a pre-set fixed number of bits for the second frame if the input signal for the second frame were encoded using a number of bits which would be required for realizing a required signal quality obtained on decoding the encoded information for the second frame, and wherein the surplus data of an arbitrary second frame is contained in the encoded information of a frame temporally posterior to the first frame.

25. The recording medium as claimed in claim 23, wherein said code string comprises surplus data which would surpass a pre-set fixed number of bits for the second frame if the input signal for the second frame were encoded using a number of bits which would be required for realizing a required signal quality obtained on decoding the encoded information for the second frame, and wherein the surplus data of an arbitrary second frame is contained in the encoded information of a frame temporally anterior to the first frame.

34. The recording medium of claim 23, wherein said second frame precedes said first frame.

35. The recording medium of claim 23, wherein said at least one second frame comprises two or more second frames.