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

• US 5,731,767 A
• Filed: 09/27/1995
• Issued: 03/24/1998
• Est. Priority Date: 02/04/1994
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Tsutsui, Kyoya, Heddle, Robert
• Primary Examiner(s): Gaffin, Jeffrey A.
• Assistant Examiner(s): JEAN PIERRE, PEGUY
• Application Number:
  US08/532,721
• Time in Patent Office: 909 Days
• Field of Search: 341/50, 341/51, 395/2.31, 395/2.34
• US Class Current: 341/50
• CPC Class Codes: G10L 19/0212 using orthogonal transformation
• CPC Class Codes: G11B 20/10527 Audio or video recording; Data buffering arrangements G11B20/12 - G11B20/18 take precedence
• CPC Class Codes: H04B 1/665 using psychoacoustic properties of the ear, e.g. masking effect

Abstract

The present invention includes an encoding and decoding apparatus and method where there is used a transform processing to allow a waveform element of a corresponding block to interfere with waveform elements of blocks adjoining in both directions at the time of inverse transform processing as in the case of, e.g., MDCT, to compose a waveform signal, amplifying processing in encoding and corresponding correction processing in decoding can be carried out without inconsistency between blocks. Thus, occurrence of pre-echo can be prevented by simple configuration by using spectrum transform processing of high encoding efficiency.

Claims

1. An information encoding method for encoding an input waveform signal,

the method comprising the steps of:

determining, on the basis of a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block;

controlling gain of a signal portion of the input waveform signal corresponding to the current block by using at least the determined gain control function of the overlapping portion;

extracting the gain-controlled signal portion so that a portion of sample of the adjacent block has the overlapping portion on the time base to transform it into a signal on the frequency base; and

encoding the transformed signal and control information for the gain control.

2. An information encoding method as set forth in claim 1,

wherein the transform processing into the signal on the frequency base includes Modified Discrete Cosine Transform processing.

3. An information encoding method as set forth in claim 1,

the method including:

detecting an attack portion where amplitude suddenly changes of the input waveform signal,

wherein control of the gain is carried out only with respect to a portion of the input waveform signal corresponding to the attack portion.

4. An information encoding method as set forth in claim 3,

wherein control of the gain is carried out only with respect to a portion of the input waveform signal in which amplitude suddenly becomes great.

5. An information encoding method as set forth in claim 1,

wherein the gain control function includes coefficients which can be selected in dependency upon the characteristic of the input waveform signal.

6. An information encoding method as set forth in claim 1,

wherein the gain control function has a smooth transient portion.

7. An information encoding method as set forth in claim 3,

wherein the control information includes position information indicating position of the attack portion by number of sub blocks obtained by subdividing the block.

8. An information encoding method as set forth in claim 1,

wherein the control information includes information shared between the adjacent blocks.

9. An information encoding apparatus adapted for encoding an input waveform signal,

the apparatus comprising:

means for determining, on the basis of a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block;

gain control means for controlling gain of a signal portion of the input waveform signal corresponding to the current block by using at least the determined gain control function of the overlapping portion,

transform means for extracting the gain controlled signal portion so that a portion of samples of the adjacent block has the overlapping portion on the time base to transform it into a signal on the frequency base; and

encoding means for encoding the transformed signal and control information for the gain control.

10. An information encoding apparatus as set forth in claim 9,

wherein the transform means carries out Modified Discrete Cosine Transform processing.

11. An information encoding apparatus as set forth in claim 9,

the apparatus further including:

detecting means for detecting an attack portion in which amplitude suddenly changes of the input waveform signal,

wherein the gain control means carries out the gain control only with respect to a portion of the input waveform signal corresponding to the attack portion detected by the detecting means.

12. An information encoding apparatus as set forth in claim 11,

wherein the gain control means carries out the gain control only with respect to the input waveform signal of which amplitude suddenly becomes great.

13. An information encoding apparatus as set forth in claim 11,

wherein the control information includes position information indicating position of the attack portion by number of sub blocks obtained by subdividing the block.

14. An information encoding apparatus as set forth in claim 9,

wherein the gain control function includes coefficients which can be selected in dependency upon the characteristic of the input waveform signal.

15. An information encoding apparatus as set forth in claim 9,

wherein the gain control function has a smooth transient portion.

16. An information encoding apparatus as set forth in claim 9,

wherein the control information includes information shared between the adjacent blocks.

17. An information decoding method for decoding a waveform signal from an encoded signal,

the method comprising the steps of:

decoding the encoded signal to take out therefrom a transformed signal and control information;

carrying out inverse transform processing for allowing waveform elements to interfere with each other between adjacent blocks with respect to the transformed signal;

determining, on the basis of the control information and a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block; and

controlling gain of a portion of the signal to which inverse-transform processing has been implemented corresponding to the current block by using at least the determined gain control function of the overlapping portion to restore an original waveform signal.

18. An information decoding method as set forth in claim 17,

wherein the inverse transform processing includes Inverse Modified Discrete Cosine Transform processing.

19. An information decoding method as set forth in claim 17,

wherein the control information includes information indicating an attack portion in which amplitude suddenly changes of the waveform signal,

the gain control being carried out only with respect to the portion corresponding to the attack portion of the signal to which the inverse transform processing has been implemented.

20. An information decoding method as set forth in claim 19,

wherein control of the gain is carried out only with respect to a portion of the signal to which the inverse transform processing has been implemented, in which amplitude suddenly becomes great.

21. An information decoding method as set forth in claim 19,

wherein the control information includes position information indicating position of the attack portion by number of sub blocks obtained by subdividing the block.

22. An information decoding method as set forth in claim 17,

wherein the control information includes information indicating gain quantity,

the gain control function being determined on the basis of the gain quantity.

23. An information decoding method as set forth in claim 17,

wherein the gain control function has a smooth transient portion.

24. An information decoding method as set forth in claim 17,

wherein the control information includes information shared between the adjacent blocks.

25. An information decoding apparatus adapted for decoding a waveform signal from an encoded signal,

the apparatus comprising:

means for decoding the encoded signal to take out therefrom a transformed signal and control information;

inverse-transform means for carrying out inverse-transform processing to allow waveform elements to interfere with each other between adjacent blocks with respect to the transformed signal;

means for determining, on the basis of a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block; and

gain control means for controlling gain of a portion of the signal to which inverse-transform processing has been implemented corresponding to the current block by using at least the determined gain control function of the overlapping portion.

26. An information decoding apparatus as set forth in claim 25,

wherein the inverse transform means carries out Inverse Modified Discrete Cosine Transform processing.

27. An information decoding apparatus as set forth in claim 26,

wherein the control information includes information indicating an attack portion where amplitude suddenly changes of the waveform signal,

the gain control means being operative to carry out the gain control only with respect to the portion corresponding to the attack portion of the signal to which the inverse transform processing has been implemented.

28. An information decoding apparatus as set forth in claim 27,

wherein the gain control means carries out the gain control only with respect to the signal to which the inverse-transform processing has been implemented, in which amplitude suddenly becomes great.

29. An information decoding apparatus as set forth in claim 27,

wherein the control information includes position information indicating position of the attack portion by number of sub blocks obtained by subdividing the block.

30. An information decoding apparatus as set forth in claim 25,

wherein the control information includes information indicating gain quantity,

the gain control function being determined on the basis of the gain quantity.

31. An information decoding apparatus as set forth in claim 25,

wherein the gain control function has a smooth transient portion.

32. An information decoding apparatus as set forth in claim 25,

wherein the control information includes information shared between the adjacent blocks.

33. An information recording medium where encoded information are recorded,

wherein spectrum signals and control information are recorded therein,

the spectrum signal being generated by:

determining, on the basis of a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block,

controlling gain of a portion of an input waveform signal corresponding to the current block by using at least the determined gain control function of the overlapping portion, and

extracting the gain-controlled signal portion so that a portion of samples of the adjacent blocks has the overlapping portion on the time base,

the control information including information for the gain control.

34. An information recording medium as set forth in claim 33,

wherein the transform processing into the signal on the frequency base includes Modified Discrete Cosine Transform processing.

35. An information recording medium as set forth in claim 33,

wherein control of the gain is carried out only with respect to a portion of the input waveform signal corresponding to an attack portion where amplitude suddenly changes of the input waveform signal.

36. An information recording medium as set forth in claim 35,

wherein control of the gain is carried out only with respect to a portion of the input waveform signal in which amplitude suddenly becomes great.

37. An information recording medium as set forth in claim 35,

wherein the control information includes position information indicating position of the attack portion by number of sub blocks obtained by subdividing the block.

38. An information recording medium as set forth in claim 33,

wherein the gain control function includes coefficients which can be selected in dependency upon the characteristic of the input waveform signal,

the control information including information indicating the coefficients.

39. An information recording medium as set forth in claim 33,

wherein the gain control function has a smooth transient portion.

40. An information recording medium as set forth in claim 33,

wherein the control information includes information shared between the adjacent blocks.

41. An information transmission method for carrying out transmission of encoded information,

the method comprising the steps of:

carrying out, in block units, transmission of a spectrum signal generated by determining, on the basis of a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block to control gain of a portion of an input waveform signal corresponding to the current block by using at least the determined gain control function of the overlapping portion to extract the gain controlled signal portion so that a portion of samples of the adjacent block has the overlapping portion on the time base to transform it into a signal on the frequency base; and

carrying out, in block units, transmission of control information for the gain control.

42. An information transmission method as set forth in claim 41,

wherein the control information includes position information indicating position of an attack portion where amplitude suddenly changes of the input waveform signal by number of sub blocks obtained by subdividing the block.

43. An information transmission method as set forth in claim 41,

wherein the control information includes information shared between the adjacent blocks.

44. An information transmission method as set forth in claim 41,

wherein the control information includes information indicating gain quantity in the gain control.

45. An information encoding method for encoding an input waveform signal,

the method comprising the steps of:

detecting an attack portion in which amplitude suddenly changes of an input waveform signal;

selectively determining a gain control function in dependency upon the characteristic of the attack portion;

controlling gain of the attack portion of the input waveform signal on the basis of the determined gain control function;

transforming the gain-controlled input waveform signal on the time base into a signal on the frequency base; and

encoding the transformed signal and control information for the gain control.

46. An information encoding method as set forth in claim 45,

wherein the gain control function has a smooth transient portion.

47. An information encoding method as set forth in claim 45,

wherein the gain control function includes coefficients which can be selected in dependency upon the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion.

48. An information encoding apparatus adapted for encoding an input waveform signal,

means for detecting an attack portion where amplitude suddenly becomes great of the input waveform signal;

means for selectively determining a gain control function in accordance with the characteristic of the attack portion;

means for controlling gain of the attack portion of the input waveform signal on the basis of the determined gain control function;

means for transforming the gain-controlled input waveform signal on the time base into a signal on the frequency base; and

means for encoding the transformed signal and control information for the gain control.

49. An information encoding apparatus as set forth in claim 48,

wherein the gain control function has a smooth transient portion.

50. An information encoding apparatus as set forth in claim 48,

wherein the gain control function includes coefficients which can be selected in accordance with the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion.

51. An information decoding method for decoding a waveform signal from an encoded signal,

the method comprising the steps of:

decoding the encoded signal to take out therefrom a transformed signal and control information;

inverse-transforming the transformed signal from a signal on the frequency base to a signal on the time base;

selectively determining a gain control function on the basis of the control information; and

controlling gain of the signal to which the inverse transform processing has been implemented corresponding to a portion of the attack portion where amplitude suddenly becomes great by using at least the determined gain control function to restore an original waveform function.

52. An information decoding method as set forth in claim 51,

wherein the gain control function has a smooth transient portion.

53. An information decoding method as set forth in claim 51,

wherein the gain control function includes coefficients which can be selected in accordance with the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion.

54. An information decoding apparatus adapted for decoding a waveform signal from an encoded signal,

the apparatus comprising:

means for decoding the encoded signal to take out therefrom a transformed signal and control information;

means for inverse-transforming the transformed signal from a signal on the frequency base to a signal on the time base;

means for selectively determining a gain control function on the basis of the control information; and

means for controlling gain of a portion of the signal to which the inverse transform processing has been implemented corresponding to an attack portion where amplitude suddenly becomes great by using at least the determined gain control function.

55. An information decoding apparatus as set forth in claim 54,

wherein the gain control function has a smooth transient portion.

56. An information decoding apparatus as set forth in claim 54,

wherein the gain control function includes coefficients which can be selected in accordance with the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion.

57. An information recording medium where encoded information are recorded,

wherein spectrum signals and control information are recorded onto or into the information recording medium,

the spectrum signal being prepared by;

detecting an attack portion in which amplitude suddenly becomes great of an input waveform signal,

selectively determining a gain control function in accordance with the characteristic of the attack portion;

controlling gain of the attack portion of the input waveform signal on the basis of the determined gain control function, and

transforming the gain-controlled input waveform signal on the time base into a signal on the frequency base,

the control information including control information for the gain control.

58. An information recording medium as set forth in claim 57,

wherein the gain control function has a smooth transient portion.

59. An information recording medium as set forth in claim 57,

wherein the gain control function includes coefficients which can be selected in accordance with the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion.

60. An information transmission method for carrying out transmission of encoded information,

the method comprising the steps of:

carrying out, in block units, transmission of a spectrum signal generated by detecting an attack portion where amplitude suddenly becomes great of an input waveform signal to selectively determine a gain control function in accordance with the characteristic of the attack portion to control gain of the attack portion of the input waveform signal on the basis of the determined gain control function to transform the gain-controlled input waveform signal on the time base into a signal on the frequency base; and

carrying out, in the block units, transmission of control information for the gain control.

61. An information transmission method as set forth in claim 60,

wherein the gain control function includes coefficients which can be selected in accordance with the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion.

62. An information encoding method for encoding an input waveform signal,

the method comprising the steps of:

determining, on the basis of a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block;

controlling gain of a signal portion of the input waveform signal corresponding to the current block by using at least the determined gain control function of the overlapping portion;

extracting the gain-controlled signal portion so that a portion of sample of the adjacent block has the overlapping portion on the time base to transform it into a signal on the frequency base; and

encoding the transformed signal and control information for the gain control, wherein the control information includes flag information indicating whether or not the gain control is carried out every block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

63. An information encoding apparatus adapted for encoding an input waveform signal, the apparatus comprising:

means for determining, on the basis of a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block;

gain control means for controlling gain of a signal portion of the input waveform signal corresponding to the current block by using at least the determined gain control function of the overlapping portion,

transform means for extracting the gain controlled signal portion so that a portion of samples of the adjacent block has the overlapping portion on the time base to transform it into a signal on the frequency base; and

encoding means for encoding the transformed signal and control information for the gain control, wherein the control information includes flag information indicating whether or not the gain control is carried out every block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

64. An information decoding method for decoding a waveform signal from an encoded signal, the method comprising the steps of:

decoding the encoded signal to take out therefrom a transformed signal and control information;

carrying out inverse transform processing for allowing waveform elements to interfere with each other between adjacent blocks with respect to the transformed signal;

determining, on the basis of the control information and a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block; and

controlling gain of a portion of the signal to which inverse-transform processing has been implemented corresponding to the current block by using at least the determined gain control function of the overlapping portion to restore an original waveform signal, wherein the control information includes flag information indicating whether or not the gain control is carried out every block, and the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

65. An information decoding apparatus adapted for decoding a waveform signal from an encoded signal, the apparatus comprising:

means for decoding the encoded signal to take out therefrom a transformed signal and control information;

inverse-transform means for carrying out inverse-transform processing to allow waveform elements to interfere with each other between adjacent blocks with respect to the transformed signal;

means for determining, on the basis of a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block; and

gain control means for controlling gain of a portion of the signal to which inverse-transform processing has been implemented corresponding to the current block by using at least the determined gain control function of the overlapping portion, wherein the control information includes flag information indicating whether or not the gain control is carried out every block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

66. An information recording medium where encoded information are recorded, wherein spectrum signals and control information are recorded therein, the spectrum signal being generated by:

determining, on the basis of a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block,

controlling gain of a portion of an input waveform signal corresponding to the current block by using at least the determined gain control function of the overlapping portion, and extracting the gain-controlled signal portion so that a portion of samples of the adjacent blocks has the overlapping portion on the time base,

the control information including information for the gain control, wherein the control information includes flag information indicating whether or not the gain control is carried out every block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

67. An information transmission method for carrying out transmission of encoded information, the method comprising the steps of:

carrying out, in block units, transmission of a spectrum signal generated by determining, on the basis of a gain control function of a block forward in point of time at an overlapping portion of a current block and the forward block, a gain control function of at least the overlapping portion of the current block to control gain of a portion of an input waveform signal corresponding to the current block by using at least the determined gain control function of the overlapping portion to extract the gain controlled signal portion so that a portion of samples of the adjacent block has the overlapping portion on the time base to transform it into a signal on the frequency base; and

carrying out, in block units, transmission of control information for the gain control, wherein the control information includes flag information indicating whether or not the gain control is carried out every block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

68. An information encoding method for encoding an input waveform signal, the method comprising the steps of:

detecting an attack portion in which amplitude suddenly changes of an input waveform signal;

selectively determining a gain control function in dependency upon the characteristic of the attack portion;

controlling gain of the attack portion of the input waveform signal on the basis of the determined gain control function;

transforming the gain-controlled input waveform signal on the time base into a signal on the frequency base; and

encoding the transformed signal and control information for the gain control, wherein the gain control function includes coefficients which can be selected in dependency upon the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion, wherein the control information includes flag information indicating whether or not the gain control is carried out every predetermined block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

69. An information encoding apparatus adapted for encoding an input waveform signal,

means for detecting an attack portion where amplitude suddenly becomes great of the input waveform signal;

means for selectively determining a gain control function in accordance with the characteristic of the attack portion;

means for controlling gain of the attack portion of the input waveform signal on the basis of the determined gain control function;

means for transforming the gain-controlled input waveform signal on the time base into a signal on the frequency base; and

means for encoding the transformed signal and control information for the gain control, wherein the gain control function includes coefficients which can be selected in accordance with the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion, wherein the control information includes flag information indicating whether or not the gain control is carried out every predetermined block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

70. An information decoding method for decoding a waveform signal from an encoded signal, the method comprising the steps of:

decoding the encoded signal to take out therefrom a transformed signal and control information;

inverse-transforming the transformed signal from a signal on the frequency base to a signal on the time base;

selectively determining a gain control function on the basis of the control information; and

controlling gain of the signal to which the inverse transform processing has been implemented corresponding to a portion of the attack portion where amplitude suddenly becomes great by using at least the determined gain control function to restore an original waveform function, wherein the gain control function includes coefficients which can be selected in accordance with the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion, wherein the control information includes flag information indicating whether or not the gain control is carried out every predetermined block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

71. An information decoding apparatus adapted for decoding a waveform signal from an encoded signal, the apparatus comprising:

means for decoding the encoded signal to take out therefrom a transformed signal and control information;

means for inverse-transforming the transformed signal from a signal on the frequency base to a signal on the time base;

means for selectively determining a gain control function on the basis of the control information; and

means for controlling gain of a portion of the signal to which the inverse transform processing has been implemented corresponding to an attack portion where amplitude suddenly becomes great by using at least the determined gain control function, wherein the gain control function includes coefficients which can be selected in accordance with the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion, wherein the control information includes flag information indicating whether or not the gain control is carried out every predetermined block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

72. An information recording medium where encoded information are recorded, wherein spectrum signals and control information are recorded onto or into the information recording medium, the spectrum signal being prepared by;

detecting an attack portion in which amplitude suddenly becomes great of an input waveform signal,

selectively determining a gain control function in accordance with the characteristic of the attack portion;

controlling gain of the attack portion of the input waveform signal on the basis of the determined gain control function, and transforming the gain-controlled input waveform signal on the time base into a signal on the frequency base,

the control information including control information for the gain control, wherein the gain control function includes coefficients which can be selected in accordance with the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion, wherein the control information includes flag information indicating whether or not the gain control is carried out every predetermined block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.

73. An information transmission method for carrying out transmission of encoded information, the method comprising the steps of:

carrying out, in block units, transmission of a spectrum signal generated by detecting an attack portion where amplitude suddenly becomes great of an input waveform signal to selectively determine a gain control function in accordance with the characteristic of the attack portion to control gain of the attack portion of the input waveform signal on the basis of the determined gain control function to transform the gain-controlled input waveform signal on the time base into a signal on the frequency base; and

carrying out, in the block units, transmission of control information for the gain control, wherein the gain control function includes coefficients which can be selected in accordance with the characteristic of the input waveform signal,

the control information including information indicating the coefficients and position information indicating position of the attack portion, wherein the control information includes flag information indicating whether or not the gain control is carried out every predetermined block, and

the control information corresponding to a block or blocks in which the gain control is not carried out consisting of only the flag information.