Method and apparatus for encoding the information, method and apparatus for decoding the information and method for information transmission

• US 6,167,093 A
• Filed: 08/11/1995
• Issued: 12/26/2000
• Est. Priority Date: 08/16/1994
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Tsutsui, Kyoya, Shimoyoshi, Osamu
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US08/514,393
• Time in Patent Office: 1,964 Days
• Field of Search: 375/241-246, 375/253, 370/207, 370/210, 341/143, 395/2, 395/2.13, 395/2.21, 395/2.38, 395/2.39, 704/203, 704/204, 704/212, 364/725.03, 364/726.01, 364/726.02, 364/726.03
• US Class Current: 375/242
• CPC Class Codes: G06F 17/147 Discrete orthonormal transforms, e.g. discrete cosine transform, discrete sine transform, and variations therefrom, e.g. modified discrete cosine transform, integer transforms approximating the discrete cosine transform G06F17/145 takes precedence

Abstract

A method and apparatus for encoding input digital data by high-efficiency encoding, a method for transmitting the encoded information and a method and apparatus for reproducing and decoding the transmitted information, are disclosed. For encoding, an input signal is forward orthogonal transformed into spectral signals using a windowing function for forward orthogonal transform having a shape A. For decoding, the spectral signals are inverse orthogonal transformed using a windowing function having a shape B different from the shape A. The degree of concentration of the energy of the spectral distribution may be raised and efficient encoding may be achieved even in case of modified DCT (MDCT) wherein the windowing function needs to satisfy a pre-set constraint.

Claims

1. An information encoding method for encoding information, comprising the steps of:

forward orthogonal transforming an input signal using a windowing function for forward orthogonal transform so that, on inverse orthogonal transform, waveform elements are conflicted between neighboring blocks for forming waveform signals; and

encoding output spectral signals produced by the forward orthogonal transform;

wherein

the shape of the windowing function for forward orthogonal transform employed in the forward orthogonal transform is different from that of a windowing function for inverse orthogonal transform employed for inverse orthogonal transform; and

further

wherein the shape of transient portions of the windowing function for forward orthogonal transform are obtained by dividing a window obtained by the equation;

##EQU10## into two and shifting where w₁ (n) is the windowing function for forward orthogonal transform, q is a value close to 1 and M is a selected number of output spectral components.

2. The information encoding method as claimed in claim 1, wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the windowing function for inverse orthogonal transform.

3. The information encoding method as claimed in claim 1, wherein the forward orthogonal transform is modified discrete cosine transform.

4. The information encoding method as claimed in claim 1, wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

5. The information encoding method as claimed in claim 1, wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

6. The information encoding method as claimed in claim 1, wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

7. The information encoding method as claimed in claim 1, wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

8. The information encoding method as claimed in claim 1, wherein the information is an acoustic signal.

9. An information decoding method for decoding information, comprising the steps of:

decoding encoded spectral signals; and

inverse orthogonal transforming the decoded spectral signals so that waveform elements will conflict with each other between neighboring blocks;

wherein

the shape of a windowing function for inverse orthogonal transform employed in the inverse orthogonal transform is different from that of a windowing function for forward orthogonal transform employed for forward orthogonal transform for producing the encoded spectral signals; and

further

wherein the shape of transient portions of the windowing function for forward orthogonal transform are obtained by dividing a window obtained by the equation;

##EQU11## into two and shifting, where w₁ (n) is the forward transform windowing function, q is a value close to 1 and M is a selected number of output spectral components.

10. The information decoding method as claimed in claim 9, wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the windowing function for the inverse orthogonal transform.

11. The information decoding method as claimed in claim 9, wherein the forward orthogonal transform is modified discrete cosine transform.

12. The information decoding method as claimed in claim 9, wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

13. The information decoding method as claimed in claim 9, wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

14. The information decoding method as claimed in claim 9, wherein the encoded spectral signals are variable length encoded signals.

15. The information decoding method as claimed in claim 9, wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

16. The information decoding method as claimed in claim 9, wherein the information is an acoustic signal.

17. An information encoding apparatus for encoding information, comprising:

means for forward orthogonal transforming an input signal using a forward orthogonal transform windowing function so that, on application of inverse orthogonal transform, waveform elements are conflicted between neighboring blocks for forming waveform signals; and

means for encoding output spectral signals produced by the forward orthogonal transform;

wherein

the shape of the forward orthogonal transform windowing function employed in the forward orthogonal transform is different from that of an inverse orthogonal transform windowing function employed for inverse orthogonal transform; and

further

wherein the shape of transient portions of the windowing function for forward orthogonal transform are obtained by dividing a window obtained by the equation;

##EQU12## into two and shifting, where w₁ (n) is the forward orthogonal transform windowing function, q is a value close to 1 and M is a selected number of output spectral components.

18. The information encoding apparatus as claimed in claim 17, wherein the maximum value of said inverse orthogonal transform windowing function does not exceed a value equal to twice a median value of the inverse orthogonal transform windowing function.

19. The information encoding apparatus as claimed in claim 17, wherein the forward orthogonal transform is modified discrete cosine transform.

20. The information encoding apparatus as claimed in claim 17, wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

21. The information encoding apparatus as claimed in claim 17, wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

22. The information encoding apparatus as claimed in claim 17, wherein the encoded spectral signals are variable length encoded signals.

23. The information encoding apparatus as claimed in claim 17, wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

24. The information encoding apparatus as claimed in claim 17, wherein the input signal is an acoustic signal.

39. The information transmission method as claimed in claim 20, wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

25. An information decoding apparatus for decoding information, comprising:

means for decoding encoded spectral signals; and

means for inverse orthogonal transforming the decoded spectral signals so that waveform elements will conflict with each other between neighboring blocks;

wherein

the shape of a windowing function for inverse orthogonal transform employed in the inverse orthogonal transform is different from that of the windowing function for forward orthogonal transform employed for forward orthogonal transform for producing the encoded spectral signals; and

further

wherein the shape of transient portions of the windowing function for forward orthogonal transform are obtained by dividing a window obtained by the equation;

##EQU13## into two and shifting, where w₁ (n) is the forward transform windowing function, q is a value close to 1 and M is a selected number of output spectral components.

26. The information decoding apparatus as claimed in claim 25, wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the windowing function for the inverse orthogonal transform.

27. The information decoding apparatus as claimed in claim 25, wherein the forward orthogonal transform is modified discrete cosine transform.

28. The information decoding apparatus as claimed in claim 25, wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

29. The information decoding apparatus as claimed in claim 25, wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

30. The information decoding apparatus as claimed in claim 25, wherein the encoded spectral signals are variable length encoded signals.

31. The information decoding apparatus as claimed in claim 25, wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

32. The information decoding apparatus as claimed in claim 25, wherein the information is an acoustic signal.

33. An information transmission method, comprising the steps of:

forward orthogonal transforming an input signal for forming spectral signals;

encoding said spectral signals;

decoding the encoded spectral signals; and

inverse orthogonal transforming said decoded spectral signals using a windowing function for inverse orthogonal transform different from the windowing function for forward orthogonal transform so that waveform elements will conflict with each other between neighboring blocks;

wherein the shape of transient portions of the windowing function for forward orthogonal transform are obtained by dividing a window obtained by the equation;

##EQU14## into two and shifting, where w₁ (n) is the forward transform windowing function, q is a value close to 1 and M is a selected number of output spectral components.

34. The information transmission method as claimed in claim 33, wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the inverse orthogonal transform windowing function.

35. The information transmission method as claimed in claim 33, wherein the forward orthogonal transform is modified discrete cosine transform.

36. The information transmission method as claimed in claim 33, wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

37. The information transmission method as claimed in claim 33, wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

38. The information transmission method as claimed in claim 33, wherein the encoded spectral signals are variable length encoded signals.

40. The information transmission method as claimed in claim 33, wherein the input signal is an acoustic signal.

41. An information encoding method for encoding information, comprising the steps of:

forward orthogonal transforming an input signal using a windowing function for forward orthogonal transform so that, on inverse orthogonal transform, waveform elements are conflicted between neighboring blocks for forming waveform signals; and

encoding output spectral signals produced by the forward orthogonal transform;

wherein the windowing function for forward orthogonal transform employed in the forward orthogonal transform is non-symmetrical;

the shape of the windowing function for forward orthogonal transform employed in the forward orthogonal transform is different from that of a windowing function for inverse orthogonal transform employed for inverse orthogonal transform; and

further

wherein the shape of transient portions of the windowing function for forward orthogonal transform are obtained by dividing a window obtained by the equation;

##EQU15## into two and shifting, where w₁ (n) is the windowing function for forward orthogonal transform, q is a value close to 1 and M is a selected number of output spectral components.

42. The method of claim 41 wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the windowing function for inverse orthogonal transform.

43. The method of claim 42 wherein the forward orthogonal transform is modified discrete cosine transform.

44. The method of claim 43 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

45. The method of claim 44 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

46. The method of claim 45 wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

47. The method of claim 46 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

48. The method of claim 47 wherein the information is an acoustic signal.

49. The method of claim 41 wherein the forward orthogonal transform is modified discrete cosine transform.

50. The method of claim 49 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

51. The method of claim 50 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

52. The method of claim 51 wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

53. The method of claim 52 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

54. The method of claim 53 wherein the information is an acoustic signal.

55. The method of claim 41 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

56. The method of claim 55 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

57. The method of claim 56 wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

58. The method of claim 57 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

59. The method of claim 58 wherein the information is an acoustic signal.

60. The method of claim 41 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

61. The method of claim 60 wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

62. The method of claim 61 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

63. The method of claim 62 wherein the information is an acoustic signal.

64. The method of claim 41 wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

65. The method of claim 64 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

66. The method of claim 65 wherein the information is an acoustic signal.

67. The method of claim 41 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

68. The method of claim 67 wherein the information is an acoustic signal.

69. The method of claim 41 wherein the information is an acoustic signal.

70. An information encoding method for encoding information, comprising the steps of:

forward orthogonal transforming an input signal using a windowing function for forward orthogonal transform so that, on inverse orthogonal transform, waveform elements are conflicted between neighboring blocks for forming waveform signals; and

encoding output spectral signals produced by the forward orthogonal transform;

wherein the windowing function for forward orthogonal transform employed in the forward orthogonal transform is non-symmetrical;

wherein the shape of the windowing function for forward orthogonal transform employed in the forward orthogonal transform is different from that of a windowing function for inverse orthogonal transform employed for inverse orthogonal transform; and

further

wherein the shape of a transient portion of the windowing function for inverse orthogonal transform is obtained by the equation;

##EQU16## where w₁ (n) is the transient portion of the windowing function for forward orthogonal transform and w₂ (n) is the transient portion of the windowing function for inverse orthogonal transform, and M is the number of components of w₁.

71. The method of claim 70 wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the windowing function for inverse orthogonal transform.

72. The method of claim 71 wherein the forward orthogonal transform is modified discrete cosine transform.

73. The method of claim 72 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

74. The method of claim 73 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

75. The method of claim 74 wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

76. The method of claim 75 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

77. The method of claim 76 wherein the information is an acoustic signal.

78. The method of claim 70 wherein the forward orthogonal transform is modified discrete cosine transform.

79. The method of claim 78 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

80. The method of claim 79 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

81. The method of claim 80 wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

82. The method of claim 81 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

83. The method of claim 82 wherein the information is an acoustic signal.

84. The method of claim 70 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

85. The method of claim 84 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

86. The method of claim 85 wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

87. The method of claim 86 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

88. The method of claim 87 wherein the information is an acoustic signal.

89. The method of claim 70 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

90. The method of claim 89 wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

91. The method of claim 90 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

92. The method of claim 91 wherein the information is an acoustic signal.

93. The method of claim 70 wherein the processing of encoding output spectral signals after the forward orthogonal transform for encoding is variable length encoding.

94. The method of claim 93 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

95. The method of claim 94 wherein the information is an acoustic signal.

96. The method of claim 70 wherein the processing of encoding output spectral signals from the forward orthogonal transform processing includes extracting and separating a specified frequency component and encoding the separated frequency component.

97. The method of claim 96 wherein the information is an acoustic signal.

98. The method of claim 70 wherein the information is an acoustic signal.

99. An information decoding method for decoding information, comprising the steps of:

decoding encoded spectral signals; and

inverse orthogonal transforming the decoded spectral signals so that waveform elements will conflict with each other between neighboring blocks;

wherein the shape of a windowing function for inverse orthogonal transform employed in the inverse orthogonal transform is different from that of a windowing function for forward orthogonal transform employed for forward orthogonal transform for producing the encoded spectral signals;

wherein the windowing function for forward orthogonal transform employed in the forward orthogonal transform is non-symmetrical; and

further

wherein the shape of transient portions of the windowing function for forward orthogonal transform are obtained by dividing a window obtained by the equation;

##EQU17## into two and shifting, where w₁ (n) is the forward transform windowing function, q is a value close to 1 and M is a selected number of output spectral components.

100. The method of claim 99 wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the windowing function for the inverse orthogonal transform.

101. The method of claim 100 wherein the forward orthogonal transform is modified discrete cosine transform.

102. The method of claim 101 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

103. The method of claim 102 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

104. The method of claim 103 wherein the encoded spectral signals are variable length encoded signals.

105. The method of claim 104 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

106. The method of claim 105 wherein the information is an acoustic signal.

107. The method of claim 99 wherein the forward orthogonal transform is modified discrete cosine transform.

108. The method of claim 107 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

109. The method of claim 108 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

110. The method of claim 109 wherein the encoded spectral signals are variable length encoded signals.

111. The method of claim 110 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

112. The method of claim 111 wherein the information is an acoustic signal.

113. The method of claim 112 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

114. The method of claim 113 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

115. The method of claim 114 wherein the encoded spectral signals are variable length encoded signals.

116. The method of claim 115 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

117. The method of claim 116 wherein the information is an acoustic signal.

118. The method of claim 117 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

119. The method of claim 118 wherein the encoded spectral signals are variable length encoded signals.

120. The method of claim 119 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

121. The method of claim 120 wherein the information is an acoustic signal.

122. The method of claim 121 wherein the encoded spectral signals are variable length encoded signals.

123. The method of claim 122 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

124. The method of claim 123 wherein the information is an acoustic signal.

125. The method of claim 124 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

126. The method of claim 125 wherein the information is an acoustic signal.

127. The method of claim 99 wherein the information is an acoustic signal.

128. An information decoding method for decoding information, comprising the steps of:

decoding encoded spectral signals; and

inverse orthogonal transforming the decoded spectral signals so that waveform elements will conflict with each other between neighboring blocks;

wherein the shape of a windowing function for inverse orthogonal transform employed in the inverse orthogonal transform is different from that of a windowing function for forward orthogonal transform employed for forward orthogonal transform for producing the encoded spectral signals;

wherein the windowing function for forward orthogonal transform employed in the forward orthogonal transform is non-symmetrical; and

further

wherein the shape of a transient portion of the windowing function for inverse orthogonal transform is obtained by the equation;

##EQU18## where w₁ (n) is the transient portion of the windowing function for forward orthogonal transform and w₂ (n) is the transient portion of the windowing function for inverse orthogonal transform, and M is the number of components of w₁.

129. The method of claim 128 wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the windowing function for the inverse orthogonal transform.

130. The method of claim 129 wherein the forward orthogonal transform is modified discrete cosine transform.

131. The method of claim 130 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

132. The method of claim 131 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

133. The method of claim 132 wherein the encoded spectral signals are variable length encoded signals.

134. The method of claim 133 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

135. The method of claim 134 wherein the information is an acoustic signal.

136. The method of claim 128 wherein the forward orthogonal transform is modified discrete cosine transform.

137. The method of claim 136 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

138. The method of claim 137 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

139. The method of claim 138 wherein the encoded spectral signals are variable length encoded signals.

140. The method of claim 139 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

141. The method of claim 140 wherein the information is an acoustic signal.

142. The method of claim 128 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

143. The method of claim 142 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

144. The method of claim 143 wherein the encoded spectral signals are variable length encoded signals.

145. The method of claim 144 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

146. The method of claim 145 wherein the information is an acoustic signal.

147. The method of claim 128 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

148. The method of claim 147 wherein the encoded spectral signals are variable length encoded signals.

149. The method of claim 148 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

150. The method of claim 149 wherein the information is an acoustic signal.

151. The method of claim 128 wherein the encoded spectral signals are variable length encoded signals.

152. The method of claim 151 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

153. The method of claim 152 wherein the information is an acoustic signal.

154. The method of claim 128 wherein part of the encoded spectral signals is obtained extracting and separating specified frequency components and encoding the separated frequency components.

155. The method of claim 154 wherein the information is an acoustic signal.

156. The method of claim 128 wherein the information is an acoustic signal.

157. An information encoding apparatus for encoding information, comprising:

means for forward orthogonal transforming an input signal using a forward orthogonal transform windowing function so that, on application of inverse orthogonal transform, waveform elements are conflicted between neighboring blocks for forming waveform signals; and

means for encoding output spectral signals produced by the forward orthogonal transform;

wherein the windowing function for forward orthogonal transform employed in the forward orthogonal transform is non-symmetrical;

the shape of the forward orthogonal transform windowing function employed in the forward orthogonal transform is different from that of an inverse orthogonal transform windowing function employed for inverse orthogonal transform; and

further

wherein the shape of transient portions of the windowing function for forward orthogonal transform are obtained by dividing a window obtained by the equation;

##EQU19## into two and shifting, where w₁ (n) is the forward orthogonal transform windowing function, q is a value close to 1 and M is a selected number of output spectral components.

158. The apparatus of claim 157 wherein the maximum value of said inverse orthogonal transform windowing function does not exceed a value equal to twice a median value of the inverse orthogonal transform windowing function.

159. The apparatus of claim 158 wherein the forward orthogonal transform is modified discrete cosine transform.

160. The apparatus of claim 159 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

161. The apparatus of claim 160 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

162. The apparatus of claim 161 wherein the encoded spectral signals are variable length encoded signals.

163. The apparatus of claim 162 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

164. The apparatus of claim 163 wherein the input signal is an acoustic signal.

165. The apparatus of claim 157 wherein the forward orthogonal transform is modified discrete cosine transform.

166. The apparatus of claim 165 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

167. The apparatus of claim 166 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

168. The apparatus of claim 167 wherein the encoded spectral signals are variable length encoded signals.

169. The apparatus of claim 168 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

170. The apparatus of claim 169 wherein the input signal is an acoustic signal.

171. The apparatus of claim 157 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

172. The apparatus of claim 171 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

173. The apparatus of claim 172 wherein the encoded spectral signals are variable length encoded signals.

174. The apparatus of claim 173 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

175. The apparatus of claim 174 wherein the input signal is an acoustic signal.

176. The apparatus of claim 157 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

177. The apparatus of claim 176 wherein the encoded spectral signals are variable length encoded signals.

178. The apparatus of claim 177 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

179. The apparatus of claim 178 wherein the input signal is an acoustic signal.

180. The apparatus of claim 157 wherein the encoded spectral signals are variable length encoded signals.

181. The apparatus of claim 180 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

182. The apparatus of claim 181 wherein the input signal is an acoustic signal.

183. The apparatus of claim 157 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

184. The apparatus of claim 183 wherein the input signal is an acoustic signal.

185. The apparatus of claim 157 wherein the input signal is an acoustic signal.

186. An information encoding apparatus for encoding information, comprising:

means for forward orthogonal transforming an input signal using a forward orthogonal transform windowing function so that, on application of inverse orthogonal transform, waveform elements are conflicted between neighboring blocks for forming waveform signals; and

means for encoding output spectral signals produced by the forward orthogonal transform;

wherein the windowing function for forward orthogonal transform employed in the forward orthogonal transform is non-symmetrical;

wherein the shape of the forward orthogonal transform windowing function employed in the forward orthogonal transform is different from that of an inverse orthogonal transform windowing function employed for inverse orthogonal transform; and

further

wherein the shape of a transient portion of the windowing function for inverse orthogonal transform is obtained by the equation;

##EQU20## where w₁ (n) is the transient portion of the windowing function for forward orthogonal transform and w₂ (n) is the transient portion of the windowing function for inverse orthogonal transform, and M is the number of components of w₁.

187. The apparatus of claim 186 wherein the maximum value of said inverse orthogonal transform windowing function does not exceed a value equal to twice a median value of the inverse orthogonal transform windowing function.

188. The apparatus of claim 187 wherein the forward orthogonal transform is modified discrete cosine transform.

189. The apparatus of claim 188 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

190. The apparatus of claim 189 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

191. The apparatus of claim 190 wherein the encoded spectral signals are variable length encoded signals.

192. The apparatus of claim 191 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

193. The apparatus of claim 192 wherein the input signal is an acoustic signal.

194. The apparatus of claim 186 wherein the forward orthogonal transform is modified discrete cosine transform.

195. The apparatus of claim 194 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

196. The apparatus of claim 195 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

197. The apparatus of claim 196 wherein the encoded spectral signals are variable length encoded signals.

198. The apparatus of claim 197 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

199. The apparatus of claim 198 wherein the input signal is an acoustic signal.

200. The apparatus of claim 186 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

201. The apparatus of claim 200 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

202. The apparatus of claim 201 wherein the encoded spectral signals are variable length encoded signals.

203. The apparatus of claim 202 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

204. The apparatus of claim 203 wherein the input signal is an acoustic signal.

205. The apparatus of claim 186 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

206. The apparatus of claim 205 wherein the encoded spectral signals are variable length encoded signals.

207. The apparatus of claim 206 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

208. The apparatus of claim 207 wherein the input signal is an acoustic signal.

209. The apparatus of claim 186 wherein the encoded spectral signals are variable length encoded signals.

210. The apparatus of claim 209 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

211. The apparatus of claim 210 wherein the input signal is an acoustic signal.

212. The apparatus of claim 186 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

213. The apparatus of claim 212 wherein the input signal is an acoustic signal.

214. The apparatus of claim 186 wherein the input signal is an acoustic signal.

215. An information decoding apparatus for decoding information, comprising:

means for decoding encoded spectral signals; and

means for inverse orthogonal transforming the decoded spectral signals so that waveform elements will conflict with each other between neighboring blocks;

wherein the shape of a windowing function for inverse orthogonal transform employed in the inverse orthogonal transform is different from that of the windowing function for forward orthogonal transform employed for forward orthogonal transform for producing the encoded spectral signals;

the windowing function for forward orthogonal transform employed in the forward orthogonal transform is non-symmetrical; and

further

wherein the shape of transient portions of the windowing function for forward orthogonal transform are obtained by dividing a window obtained by the equation;

##EQU21## into two and shifting, where w₁ (n) is the forward transform windowing function, q is a value close to 1 and M is a selected number of output spectral components.

216. The apparatus of claim 215 wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the windowing function for the inverse orthogonal transform.

217. The apparatus of claim 216 wherein the forward orthogonal transform is modified discrete cosine transform.

218. The apparatus of claim 217 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

219. The apparatus of claim 218 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

220. The apparatus of claim 219 wherein the encoded spectral signals are variable length encoded signals.

221. The apparatus of claim 220 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

222. The apparatus of claim 221 wherein the information is an acoustic signal.

223. The apparatus of claim 215 wherein the forward orthogonal transform is modified discrete cosine transform.

224. The apparatus of claim 223 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

225. The apparatus of claim 224 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

226. The apparatus of claim 225 wherein the encoded spectral signals are variable length encoded signals.

227. The apparatus of claim 226 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

228. The apparatus of claim 227 wherein the information is an acoustic signal.

229. The apparatus of claim 215 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

230. The apparatus of claim 229 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

231. The apparatus of claim 230 wherein the encoded spectral signals are variable length encoded signals.

232. The apparatus of claim 231 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

233. The apparatus of claim 232 wherein the information is an acoustic signal.

234. The apparatus of claim 215 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

235. The apparatus of claim 234 wherein the encoded spectral signals are variable length encoded signals.

236. The apparatus of claim 235 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

237. The apparatus of claim 236 wherein the information is an acoustic signal.

238. The apparatus of claim 215 wherein the encoded spectral signals are variable length encoded signals.

239. The apparatus of claim 238 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

240. The apparatus of claim 239 wherein the information is an acoustic signal.

241. The apparatus of claim 215 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

242. The apparatus of claim 241 wherein the information is an acoustic signal.

243. The apparatus of claim 215 wherein the information is an acoustic signal.

244. An information decoding apparatus for decoding information, comprising:

means for decoding encoded spectral signals; and

means for inverse orthogonal transforming the decoded spectral signals so that waveform elements will conflict with each other between neighboring blocks;

wherein the shape of a windowing function for inverse orthogonal transform employed in the inverse orthogonal transform is different from that of the windowing function for forward orthogonal transform employed for forward orthogonal transform for producing the encoded spectral signals;

wherein the windowing function for forward orthogonal transform employed in the forward orthogonal transform is non-symmetrical; and

further

wherein the shape of a transient portion of the windowing function for inverse orthogonal transform is obtained by the equation;

##EQU22## where w₁ (n) is the transient portion of the windowing function for forward orthogonal transform and w₂ (n) is the transient portion of the windowing function for inverse orthogonal transform, and M is the number of components of w₁.

245. The apparatus of claim 244 wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the windowing function for the inverse orthogonal transform.

246. The apparatus of claim 245 wherein the forward orthogonal transform is modified discrete cosine transform.

247. The apparatus of claim 246 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

248. The apparatus of claim 247 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

249. The apparatus of claim 248 wherein the encoded spectral signals are variable length encoded signals.

250. The apparatus of claim 249 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

251. The apparatus of claim 250 wherein the information is an acoustic signal.

252. The apparatus of claim 244 wherein the forward orthogonal transform is modified discrete cosine transform.

253. The apparatus of claim 252 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

254. The apparatus of claim 253 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

255. The apparatus of claim 254 wherein the encoded spectral signals are variable length encoded signals.

256. The apparatus of claim 255 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

257. The apparatus of claim 256 wherein the information is an acoustic signal.

258. The apparatus of claim 244 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

259. The apparatus of claim 258 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

260. The apparatus of claim 259 wherein the encoded spectral signals are variable length encoded signals.

261. The apparatus of claim 260 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

262. The apparatus of claim 261 wherein the information is an acoustic signal.

263. The apparatus of claim 244 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

264. The apparatus of claim 263 wherein the encoded spectral signals are variable length encoded signals.

265. The apparatus of claim 264 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

266. The apparatus of claim 265 wherein the information is an acoustic signal.

267. The apparatus of claim 244 wherein the encoded spectral signals are variable length encoded signals.

268. The apparatus of claim 267 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

269. The apparatus of claim 268 wherein the information is an acoustic signal.

270. The apparatus of claim 244 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

271. The apparatus of claim 270 wherein the information is an acoustic signal.

272. The apparatus of claim 244 wherein the information is an acoustic signal.

273. An information transmission method, comprising the steps of:

forward orthogonal transforming an input signal using a non-symmetrical windowing function for forward orthogonal transform for forming spectral signals;

encoding said spectral signals;

decoding the encoded spectral signals; and

inverse orthogonal transforming said decoded spectral signals using a windowing function for inverse orthogonal transform different from the windowing function for forward orthogonal transform so that waveform elements will conflict with each other between neighboring blocks;

wherein the shape of transient portions of the windowing function for forward orthogonal transform are obtained by dividing a window obtained by the equation;

##EQU23## into two and shifting, where w₁ (n) is the forward transform windowing function, q is a value close to 1 and M is a selected number of output spectral components.

274. The method of claim 273 wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the inverse orthogonal transform windowing function.

275. The method of claim 274 wherein the forward orthogonal transform is modified discrete cosine transform.

276. The method of claim 275 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

277. The method of claim 276 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

278. The method of claim 277 wherein the encoded spectral signals are variable length encoded signals.

279. The method of claim 278 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

280. The method of claim 279 wherein the input signal is an acoustic signal.

281. The method of claim 273 wherein the forward orthogonal transform is modified discrete cosine transform.

282. The method of claim 281 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

283. The method of claim 282 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

284. The method of claim 283 wherein the encoded spectral signals are variable length encoded signals.

285. The method of claim 284 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

286. The method of claim 285 wherein the input signal is an acoustic signal.

287. The method of claim 273 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

288. The method of claim 287 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

289. The method of claim 288 wherein the encoded spectral signals are variable length encoded signals.

290. The method of claim 289 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

291. The method of claim 290 wherein the input signal is an acoustic signal.

292. The method of claim 273 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

293. The method of claim 292 wherein the encoded spectral signals are variable length encoded signals.

294. The method of claim 293 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

295. The method of claim 294 wherein the input signal is an acoustic signal.

296. The method of claim 273 wherein the encoded spectral signals are variable length encoded signals.

297. The method of claim 296 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

298. The method of claim 297 wherein the input signal is an acoustic signal.

299. The method of claim 273 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

300. The method of claim 299 wherein the input signal is an acoustic signal.

301. The method of claim 273 wherein the input signal is an acoustic signal.

302. An information transmission method, comprising the steps of:

forward orthogonal transforming an input signal using a non-symmetrical windowing function for forward orthogonal transform for forming spectral signals;

encoding said spectral signals;

decoding the encoded spectral signals; and

inverse orthogonal transforming said decoded spectral signals using a windowing function for inverse orthogonal transform different from the windowing function for forward orthogonal transform so that waveform elements will conflict with each other between neighboring blocks;

wherein the shape of a transient portion of the windowing function for inverse orthogonal transform is obtained by the equation;

##EQU24## where w₁ (n) is the transient portion of the windowing function for forward orthogonal transform and w₂ (n) is the transient portion of the windowing function for inverse orthogonal transform, and M is the number of components of w₁.

303. The method of claim 302 wherein the maximum value of said windowing function for inverse orthogonal transform does not exceed a value equal to twice a median value of the inverse orthogonal transform windowing function.

304. The method of claim 303 wherein the forward orthogonal transform is modified discrete cosine transform.

305. The method of claim 304 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

306. The method of claim 305 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

307. The method of claim 306 wherein the encoded spectral signals are variable length encoded signals.

308. The method of claim 307 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

309. The method of claim 308 wherein the input signal is an acoustic signal.

310. The method of claim 302 wherein the forward orthogonal transform is modified discrete cosine transform.

311. The method of claim 310 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

312. The method of claim 311 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

313. The method of claim 312 wherein the encoded spectral signals are variable length encoded signals.

314. The method of claim 313 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

315. The method of claim 314 wherein the input signal is an acoustic signal.

316. The method of claim 302 wherein the windowing function for forward orthogonal transform has a domain having a value of zero.

317. The method of claim 316 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

318. The method of claim 317 wherein the encoded spectral signals are variable length encoded signals.

319. The method of claim 318 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

320. The method of claim 319 wherein the input signal is an acoustic signal.

321. The method of claim 320 wherein the entire domain of the windowing function for forward orthogonal transform has a value of zero.

322. The method of claim 321 wherein the encoded spectral signals are variable length encoded signals.

323. The method of claim 322 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

324. The method of claim 323 wherein the input signal is an acoustic signal.

325. The method of claim 302 wherein the encoded spectral signals are variable length encoded signals.

326. The method of claim 325 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

327. The method of claim 326 wherein the input signal is an acoustic signal.

328. The method of claim 302 wherein part of the encoded spectral signals is obtained by extracting and separating specified frequency components and encoding the separated frequency components.

329. The method of claim 328 wherein the input signal is an acoustic signal.

330. The method of claim 302 wherein the input signal is an acoustic signal.

331. An information encoding method for encoding information, comprising the steps of:

forward orthogonal transforming an input signal using a windowing function for forward orthogonal transform so that, on inverse orthogonal transform, waveform elements are conflicted between neighboring blocks for forming waveform signals; and

encoding output spectral signals produced by the forward orthogonal transform;

wherein the shape of the windowing function for forward orthogonal transform employed in the forward orthogonal transform is different from that of a windowing function for inverse orthogonal transform employed for inverse orthogonal transform; and

further

wherein the shape of a transient portion of the windowing function for inverse orthogonal transform is obtained by the equation;

##EQU25## where w₁ (n) is the transient portion of the windowing function for forward orthogonal transform and w₂ (n) is the transient portion of the windowing function for inverse orthogonal transform, and M is the number of components of w₁.

332. An information decoding method for decoding information, comprising the steps of:

decoding encoded spectral signals; and

inverse orthogonal transforming the decoded spectral signals so that waveform elements will conflict with each other between neighboring blocks;

wherein

the shape of a windowing function for inverse orthogonal transform employed in the inverse orthogonal transform is different from that of a windowing function for forward orthogonal transform employed for forward orthogonal transform for producing the encoded spectral signals; and

further

wherein the shape of a transient portion of the windowing function for inverse orthogonal transform is obtained by the equation;

##EQU26## where w₁ (n) is the transient portion of the windowing function for forward orthogonal transform and w₂ (n) is the transient portion of the windowing function for inverse orthogonal transform, and M is the number of components of w₁.

333. An information encoding apparatus for encoding information, comprising:

means for forward orthogonal transforming an input signal using a forward orthogonal transform windowing function so that, on application of inverse orthogonal transform, waveform elements are conflicted between neighboring blocks for forming waveform signals; and

means for encoding output spectral signals produced by the forward orthogonal transform;

wherein the shape of the forward orthogonal transform windowing function employed in the forward orthogonal transform is different from that of an inverse orthogonal transform windowing function employed for inverse orthogonal transform; and

further

wherein the shape of a transient portion of the windowing function for inverse orthogonal transform is obtained by the equation;

##EQU27## where w₁ (n) is the transient portion of the windowing function for forward orthogonal transform and w₂ (n) is the transient portion of the windowing function for inverse orthogonal transform, and M is the number of components of w₁.

334. An information decoding apparatus for decoding information, comprising:

means for decoding encoded spectral signals; and

means for inverse orthogonal transforming the decoded spectral signals so that waveform elements will conflict with each other between neighboring blocks;

wherein

the shape of a windowing function for inverse orthogonal transform employed in the inverse orthogonal transform is different from that of the windowing function for forward orthogonal transform employed for forward orthogonal transform for producing the encoded spectral signals; and

further

wherein the shape of a transient portion of the windowing function for inverse orthogonal transform is obtained by the equation;

##EQU28## where w₁ (n) is the transient portion of the windowing function for forward orthogonal transform and w₂ (n) is the transient portion of the windowing function for inverse orthogonal transform, and M is the number of components of w₁.

335. An information transmission method, comprising the steps of:

forward orthogonal transforming an input signal for forming spectral signals;

encoding said spectral signals;

decoding the encoded spectral signals; and

inverse orthogonal transforming said decoded spectral signals using a windowing function for inverse orthogonal transform different from the windowing function for forward orthogonal transform so that waveform elements will conflict with each other between neighboring blocks;

wherein the shape of a transient portion of the windowing function for inverse orthogonal transform is obtained by the equation;

##EQU29## where w₁ (n) is the transient portion of the windowing function for forward orthogonal transform and w₂ (n) is the transient portion of the windowing function for inverse orthogonal transform, and M is the number of components of w₁.