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BR-PI0716315-B1 - Apparatus and method for generating audio subband values and apparatus and method for generating time-domain audio samples.

Abstract

APPARATUS AND METHOD FOR GENERATING AUDIO SUB-BAND VALUES AND APPARATUS AND METHOD FOR GENERATING TIME-DOMAIN AUDIO SAMPLES. An apparatus configuration (100) for generating audio sub-band values in audio sub-band channels comprises an analysis windower (110) for working with windows in a time-domain audio input sample frame (120) being in a time sequence extending from a previous sample to a subsequent sample using an analysis window function (190) comprising a sequence of window coefficients to obtain windowed samples. The analysis window function (190) comprises a first group (200) of window coefficients comprising a first portion of the window coefficient sequence and a second group (210) of window coefficients comprising a second portion of the window coefficient sequence, wherein the first portion comprises fewer window coefficients than the second portion and wherein an energy value of the window coefficients in the first portion is greater than the energy value of the window coefficients in the second portion. The first group of window coefficients is used for domain samples (...).

Inventors

  • Markus Schnell
  • Bernd Edler
  • Manfred Lutzky
  • Markus Schmidt
  • Marc Gayer
  • Michael Mellar
  • Markus Multrus
  • Gerald Schuller
  • Ralf Geiger
  • Bernhard Grill
  • Markus Lohwasser

Assignees

  • Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V

Dates

Publication Date
20260317
Application Date
20071023
Priority Date
20061025

Claims (8)

  1. 1. Apparatus for generating complex audio sub-band values in audio sub-band channels characterized by comprising: an analysis window applicator (110) for windowing a frame (120) of audio input samples in the time domain, these samples being in a time sequence extending from an oldest sample to a most recent sample, using an analysis window function (190) comprising a sequence of window coefficients to acquire windowed samples, wherein the analysis window function (190) comprises a first group (200) of window coefficients comprising a first portion of the window coefficient sequence and a second group (210) of window coefficients comprising a second portion of the window coefficient sequence, wherein the first portion comprises fewer window coefficients than the second portion, wherein a total energy value of the window coefficients in the first portion is greater than a total energy value of the window coefficients in the second portion, wherein the first group of window coefficients is used for windowing samples in the most recent time domain and the second group of window coefficients is used for windowing samples in the older time domain; and a calculator (170) for calculating audio sub-band values using the windowed samples, wherein the calculator (170) comprises a time/frequency converter adapted to generate audio sub-band values such that all sub-band values based on a frame (150) of windowed samples represent a spectral representation of the windowed samples of the frame (150) of windowed samples, and wherein the time/frequency converter is adapted to generate complex audio sub-band values.
  2. 2. Apparatus (100), according to claim 1, characterized in that the analysis window applicator (110) is adapted so that the analysis window function (190) is asymmetric with respect to the sequence of window coefficients.
  3. 3. Apparatus (100), according to claim 1, characterized in that the analysis window applicator (110) is adapted so that a central point of the window coefficients of the analysis window function corresponds to a real value in a range of indices of the first portion of the window coefficients.
  4. 4. Apparatus (100), according to claim 1, characterized in that the analysis window applicator is adapted in such a way that the analysis window function (110) comprises a strictly monotonic decrease of the window coefficient comprising the highest absolute value of all window coefficients of the analysis window function to a window coefficient of the sequence of window coefficients used for windowing the audio sample in the most recent time domain.
  5. 5. Apparatus (100), according to claim 1, characterized in that the analysis window applicator (110) is adapted so that the window coefficient corresponding to an index n = (T-1) • N comprises an absolute value in the range of 0.9 to 1.1, wherein an index of the sequence of window coefficients is an integer in the range of 0 to N • T - 1, wherein the window coefficient used for windowing the most recent time-domain audio input sample of the frame is the window coefficient corresponding to the index N • T - 1, wherein the analysis window applicator is adapted so that the time-domain audio input sample frame comprises a sequence of blocks T of time-domain audio input samples extending from the oldest to the most recent time-domain audio input samples of the frame, wherein each block comprises N time-domain audio input samples, and wherein T and N are positive integers and T is greater than 4, wherein the window applicator The analysis is adapted so that the window coefficient corresponding to the window coefficient index n = N • T - 1 comprises an absolute value less than 0.02.
  6. 6. Apparatus (100), according to claim 1, characterized in that the analysis window applicator (110) is adapted so that the window comprises the multiplication of the time-domain audio input samples x(n) of the frame to acquire the windowed samples z(n) of the windowed frame based on the equation z(n) = x(n) • w(n) where n is an integer indicating an index of the sequence of window coefficients in the range from 0 to T • N-1, where w(n) is the window coefficient of the analysis window function (110) corresponding to the index n, where x(N • T-1) is the most recent time-domain audio input sample of a frame (120) of time-domain audio input samples, wherein the analysis window applicator is adapted so that the time-domain audio input sample frame comprises a sequence of blocks T (130) of time-domain audio input samples extending from the samples of Audio input samples in the time domain are older than those in the time domain than those in the most recent audio input samples in the frame, where each block comprises N audio input samples in the time domain, and where T and N are positive integers and T is greater than 4, where the analysis window applicator is adapted so that the window coefficients c(n) obey the following relationships: 0.010 < | w[0] | < 0.012 0.023 < | w[1] | < 0.025 0.034 < | w[2] | < 0.036 0.045 < | w[3] | < 0.047 0.058 < | w[4] | < 0.060 0.072 < | w[5] | < 0.074 0.087 < | w[6] | < 0.089 0.103 < | w[7] | < 0.105 0.120 < | w[8] | < 0.122 0.137 < | w[9] | < 0.139 0.154 < | w[10] | < 0.156 0.171 < | w[11] | < 0.173 0.188 < w[12] < 0.190 0.205 < w[13] < 0.207 0.222 < w[14] < 0.224 0.239 < w[15] < 0.241 0.256 < w[16] < 0.258 0.272 < w[17] < 0.274 0.289 < w[18] < 0.291 0.306 < w[19] < 0.308 0.323 < w[20] < 0.325 0.339 < w[21] < 0.341 0.356 < w[22] < 0.358 0.373 < w[23] < 0.375 0.390 < w[24] < 0.392 0.407 < w[25] < 0.409 0.424 < w[26] < 0.426 0.441 < w[27] < 0.443 0.458 < w[28] < 0.460 0.475 < w[29] < 0.477 0.492 < w[30] < 0.494 0.509 < w[31] < 0.511 0.525 < w[32] < 0.527 0.542 < w[33] < 0.544 0.559 < w[34] < 0.561 0.575 < w[35] < 0.577 0.592 < w[36] < 0.594 0.609 < w[37] < 0.611 0.625 < w[38] < 0.627 0.642 < w[39] < 0.644 0.658 < w[40] < 0.660 0.674 < w[41] < 0.676 0.690 < w[42] < 0.692 0.706 < w[43] < 0.708 0.722 < w[44] < 0.724 0.738 < w[45] < 0.740 0.753 < w[46] < 0.755 0.769 < w[47] < 0.771 0.784 < w[48] < 0.786 0.799 < w[49] < 0.801 0.815 < w[50] < 0.817 0.830 < w[51] < 0.832 0.845 < w[52] < 0.847 0.860 < w[53] < 0.862 0.874 < w[54] < 0.876 0.889 < w[55] < 0.891 0.903 < w[56] < 0.905 0.917 < w[57] < 0.919 0.930 < w[58] < 0.932 0.943 < w[59] < 0.945 0.956 < w[60] < 0.958 0.968 < w[61] < 0.970 0.980 < w[62] < 0.982 0.992 < w[63] < 0.994 1.000 < w[64] < 1.002 1.006 < w[65] < 1.008 1.012 < w[66] < 1.014 1.017 < w[67] < 1.019 1.021 < w[68] < 1.023 1.026 < w[69] < 1.028 1.029 < w[70] < 1.031 1.032 < w[71] < 1.034 1.035 < w[72] < 1.037 1.037 < w[73] < 1.039 1.038 < w[74] < 1,040 1,039 < w[75] < 1.041 1.040 < w[76] < 1.042 1.040 < w[77] < 1.042 1.040 < w[78] < 1.042 1.040 < w[79] < 1.042 1.039 < w[80] < 1.041 1.038 < w[81] < 1.040 1.036 < w[82] < 1.038 1.034 < w[83] < 1.036 1.032 < w[84] < 1.034 1.029 < w[85] < 1.031 1.025 < w[86] < 1.027 1.021 < w[87] < 1.023 1.016 < I w[88] | < 1.018 1.011 < I w[89] I < 1.013 1.005 < | w[90] | < 1.007 0.999 < I w[91] I < 1.001 0.992 < I w[92] I < 0.994 0.985 < I w[93] I < 0.987 0.977 < I w[94] I < 0.979 0.969 < I w[95] I < 0.971 0.960 < I w[96] I < 0.962 0.951 < I w[97] I < 0.953 0.941 < I w[98] I < 0.943 0.931 < I w[99] I < 0.933 0.920 < w[100] < 0.922 0.909 < w[101] < 0.911 0.897 < w[102] < 0.899 0.885 < w[103] < 0.887 0.872 < w[104] < 0.874 0.860 < w[105] < 0.862 0.846 < w[106] < 0.848 0.833 < w[107] < 0.835 0.819 < w[108] < 0.821 0.804 < w[109] < 0.806 0.790 < w[110] < 0.792 0.775 < w[111] < 0.777 0.760 < w[112] < 0.762 0.745 < w[113] < 0.747 0.729 < w[114] < 0.731 0.713 < w[115] < 0.715 0.697 < w[116] < 0.699 0.681 < w[117] < 0.683 0.664 < w[118] < 0.666 0.648 < w[119] < 0.650 0.631 < w[120] < 0.633 0.614 < w[121] < 0.616 0.597 < w[122] < 0.599 0.580 < w[123] < 0.582 0.563 < w[124] < 0.565 0.546 < w[125] < 0.548 0.529 < w[126] < 0.531 0.512 < w[127] < 0.514 0.495 < w[128] < 0.497 0.477 < w[129] < 0.479 0.460 < w[130] < 0.462 0.443 < w[131] < 0.445 0.426 < w[132] < 0.428 0.409 < w[133] < 0.411 0.392 < w[134] < 0.394 0.375 < w[135] < 0.377 0.358 < w[136] < 0.360 0.341 < w[137] < 0.343 0.325 < w[138] < 0.327 0.309 < w[139] < 0.311 0.293 < w[140] < 0.295 0.277 < w[141] < 0.279 0.261 < w[142] < 0.263 0.246 < w[143] < 0.248 0.231 < w[144] < 0.233 0.216 < w[145] < 0.218 0.201 < w[146] < 0.203 0.187 < w[147] < 0.189 0.173 < w[148] < 0.175 0.159 < w[149] < 0.161 0.145 < w[150] < 0.147 0.132 < w[151] < 0.134 0.119 < w[152] < 0.121 0.106 < w[153] < 0.108 0.094 < w[154] < 0.096 0.082 < w[155] < 0.084 0.070 < w[156] < 0.072 0.059 < w[157] < 0.061 0.048 < w[158] < 0.050 0.037 < w[159] < 0.039 0.026 < w[160] < 0.028 0.016 < w[161] < 0.018 0.006 < w[162] < 0.008 0.001 < w[163] < 0.003 0.010 < w[164] < 0.012 0.019 < w[165] < 0.021 0.028 < w[166] < 0.030 0.036 < w[167] < 0.038 0.043 < w[168] < 0.045 0.051 < w[169] < 0.053 0.058 < w[170] < 0.060 0.065 < w[171] < 0.067 0.071 < w[172] < 0.073 0.077 < w[173] < 0.079 0.082 < w[174] < 0.084 0.088 < w[175] < 0.090 0.093 < w[176] < 0.095 0.097 < w[177] < 0.099 0.101 < w[178] < 0.103 0.105 < w[179] < 0.107 0.109 < w[180] < 0.111 0.112 < w[181] < 0.114 0.115 < w[182] < 0.117 0.117 < w[183] < 0.119 0.119 < w[184] < 0.121 0.121 < w[185] < 0.123 0.123 < w[186] < 0.125 0.124 < w[187] < 0.126 0.125 < w[188] < 0.127 0.126 < w[189] < 0.128 0.126 < w[190] < 0.128 0.126 < w[191] < 0.128 0.126 < w[192] < 0.128 0.127 < w[193] < 0.129 0.126 < w[194] < 0.128 0.126 < w[195] < 0.128 0.125 < w[196] < 0.127 0.124 < w[197] < 0.126 0.123 < w[198] < 0.125 0.122 < w[199] < 0.124 0.121 < w[200] < 0.123 0.119 < w[201] < 0.121 0.118 < w[202] < 0.120 0.116 < w[203] < 0.118 0.114 < w[204] < 0.116 0.111 < w[205] < 0.113 0.109 < w[206] < 0.111 0.107 < w[207] < 0.109 0.104 < w[208] < 0.106 0.102 < w[209] < 0.104 0.099 < w[210] < 0.101 0.096 < w[211] < 0.098 0.093 < w[212] < 0.095 0.090 < w[213] < 0.092 0.087 < w[214] < 0.089 0.084 < w[215] < 0.086 0.082 < w[216] < 0.084 0.079 < w[217] < 0.081 0.076 < w[218] < 0.078 0.073 < w[219] < 0.075 0.070 < w[220] < 0.072 0.067 < w[221] < 0.069 0.064 < w[222] < 0.066 0.061 < w[223] < 0.063 0.058 < w[224] < 0.060 0.055 < w[225] < 0.057 0.053 < w[226] < 0.055 0.050 < w[227] < 0.052 0.047 < w[228] < 0.049 0.045 < w[229] < 0.047 0.043 < w[230] < 0.045 0.040 < w[231] < 0.042 0.038 < w[232] < 0.040 0.036 < w[233] < 0.038 0.034 < w[234] < 0.036 0.032 < w[235] < 0.034 0.030 < w[236] < 0.032 0.028 < w[237] < 0.030 0.027 < w[238] < 0.029 0.025 < w[239] < 0.027 0.023 < w[240] < 0.025 0.022 < w[241] < 0.024 0.021 < w[242] < 0.023 0.019 < w[243] < 0.021 0.018 < w[244] < 0.020 0.017 < w[245] < 0.019 0.016 < w[246] < 0.018 0.015 < w[247] < 0.017 0.014 < w[248] < 0.016 0.013 < w[249] < 0.015 0.012 < w[250] < 0.014 0.011 < w[251] < 0.013 0.010 < w[252] < 0.012 0.009 < w[253] < 0.011 0.009 < w[254] < 0.011 0.008 < w[255] < 0.010 0.007 < w[256] < 0.009 0.007 < w[257] < 0.009 0.006 < w[258] < 0.008 0.006 < w[259] < 0.008 0.006 < w[260] < 0.008 0.005 < w[261] < 0.007 0.005 < w[262] < 0.007 0.004 < w[263] < 0.006 0.004 < w[264] < 0.006 0.004 < w[265] < 0.006 0.003 < w[266] < 0.005 0.003 < w[267] < 0.005 0.003 < w[268] < 0.005 0.003 < w[269] < 0.005 0.002 < w[270] < 0.004 0.002 < w[271] < 0.004 0.002 < w[272] < 0.004 0.001 < w[273] < 0.003 0.001 < w[274] < 0.003 0.001 < w[275] < 0.003 0.001 < w[276] < 0.003 0.000 < w[277] < 0.002 0.000 < I w[278] | < 0.002 0.000 < I w[279] I < 0.002 0.000 < I w[280] I < 0.002 0.000 < I w[281] I < 0.002 0.000 < I w[282] I < 0.002 -0.001 < I w[283] I < 0.001 -0.001 < I w[284] I < 0.001 -0.001 < I w[285] I < 0.001 -0.001 < I w[286] I < 0.001 0.000 < I w[287] I < 0.002 0.000 < I w[288] I < 0.002 0.000 < I w[289] I < 0.002 0.000 < I w[290] I < 0.002 0.000 < I w[291] I < 0.002 0.001 < I w[292] I < 0.003 0.001 < I w[293] I < 0.003 0.001 < I w[294] I < 0.003 0.001 < I w[295] I < 0.003 0.000 < I w[296] I < 0.002 0.000 < I w[297] I < 0.002 0.000 < I w[298] I < 0.002 -0.001 < I w[299] I < 0.001 -0.001 < I w[300] I < 0.001 0.000 < I w[301] I < 0.002 0.000 < I w[302] I < 0.002 0.001 < I w[303] I < 0.003 0.001 < I w[304] I < 0.003 0.002 < I w[305] I < 0.004 0.002 < I w[306] I < 0.004 0.002 < I w[307] I < 0.004 0.003 < I w[308] I < 0.005 0.003 < I w[309] I < 0.005 0.003 < I w[310] I < 0.005 0.004 < I w[311] I < 0.006 0.004 < I w[312] I < 0.006 0.004 < I w[313] I < 0.006 0.004 < I w[314] I < 0.006 0.004 < I w[315] I < 0.006 0.004 < w[316] < 0.006 0.003 < w[317] < 0.005 0.003 < w[318] < 0.005 0.003 < w[319] < 0.005 0.003 < w[320] < 0.005 0.002 < w[321] < 0.004 0.002 < w[322] < 0.004 0.002 < w[323] < 0.004 0.001 < w[324] < 0.003 0.001 < w[325] < 0.003 0.001 < w[326] < 0.003 0.000 < w[327] < 0.002 0.000 < w[328] < 0.002 -0.001 < | w[329] | < 0.001 -0.001 < | w[330] | < 0.001 -0.001 < | w[331] | < 0.001 -0.001 < | w[332] | < 0.001 -0.001 < | w[333] | < 0.001 0.000 < w[334] < 0.002 0.000 < | w[335] < 0.002 0.000 < | w[336] < 0.002 0.000 < | w[337] < 0.002 0.000 < w[338] < 0.002 0.000 < | w[339] < 0.002 0.000 < w[340] < 0.002 0.000 < w[341] < 0.002 0.000 < w[342] < 0.002 0.000 < w[343] < 0.002 -0.001 < | w[344] | < 0.001 -0.001 < | w[345] | < 0.001 0.000 < | w[346] < 0.002 0.000 < | w[347] < 0.002 0.001 < | w[348] < 0.003 0.001 < | w[349] < 0.003 0.001 < | w[350] < 0.003 0.002 < | w[351] < 0.004 0.002 < | w[352] < 0.004 0.002 < | w[353] < 0.004 0.002 < w[354] < 0.004 0.002 < w[355] < 0.004 0.001 < w[356] < 0.003 0.001 < w[357] < 0.003 0.001 < w[358] < 0.003 0.001 < w[359] < 0.003 0.001 < w[360] < 0.003 0.000 < w[361] < 0.002 0.000 < w[362] < 0.002 0.000 < w[363] < 0.002 -0.001 < | w[364] | < 0.001 -0.001 < | w[365] | < 0.001 -0.001 < | w[366] | < 0.001 -0.001 < | w[367] | < 0.001 0.000 < w[368] < 0.002 0.000 < | w[369] < 0.002 0.000 < | w[370] < 0.002 0.000 < | w[371] < 0.002 0.000 < | w[372] < 0.002 0.000 < | w[373] < 0.002 0.000 < | w[374] < 0.002 0.000 < | w[375] < 0.002 0.000 < | w[376] < 0.002 0.000 < | w[377] < 0.002 0.000 < w[378] < 0.002 0.000 < | w[379] < 0.002 0.000 < | w[380] < 0.002 0.000 < | w[381] < 0.002 0.000 < | w[382] < 0.002 0.000 < | w[383] < 0.002 0.000 < | w[384] < 0.002 0.000 < | w[385] < 0.002 0.000 < | w[386] < 0.002 0.000 < | w[387] < 0.002 0.000 < | w[388] < 0.002 0.000 < | w[389] < 0.002 0.000 < | w[390] < 0.002 0.000 < | w[391] < 0.002 0.000 < | w[392] | < 0.002 0.000 < | w[393] | < 0.002 -0.001 < w[394] < 0.001 -0.001 < | w[395] < 0.001 -0.001 < w[396] < 0.001 -0.001 < w[397] < 0.001 -0.001 < w[398] < 0.001 -0.001 < | w[399] < 0.001 -0.001 < w[400] < 0.001 -0.001 < w[401] < 0.001 -0.001 < w[402] < 0.001 -0.001 < w[403] < 0.001 -0.001 < w[404] < 0.001 -0.001 < w[405] < 0.001 -0.001 < w[406] < 0.001 -0.001 < | w[407] < 0.001 -0.001 < w[408] < 0.001 -0.001 < | w[409] < 0.001 -0.001 < | w[410] < 0.001 -0.001 < | w[411] < 0.001 -0.001 < | w[412] < 0.001 -0.001 < | w[413] < 0.001 -0.001 < | w[414] < 0.001 -0.001 < | w[415] < 0.001 -0.001 < | w[416] < 0.001 -0.001 < | w[417] < 0.001 -0.001 < w[418] < 0.001 -0.001 < | w[419] < 0.001 -0.001 < | w[420] < 0.001 -0.001 < | w[421] < 0.001 -0.001 < | w[422] < 0.001 -0.001 < | w[423] < 0.001 -0.001 < | w[424] < 0.001 -0.001 < | w[425] < 0.001 -0.001 < | w[426] < 0.001 -0.001 < | w[427] < 0.001 -0.001 < | w[428] < 0.001 -0.001 < | w[429] < 0.001 -0.001 < w[430] < 0.001 -0.001 < w[431] < 0.001 -0.001 < w[432] < 0.001 -0.001 < w[433] < 0.001 -0.001 < w[434] < 0.001 -0.001 < w[435] < 0.001 -0.001 < w[436] < 0.001 -0.001 < w[437] < 0.001 -0.001 < w[438] < 0.001 -0.001 < w[439] < 0.001 -0.001 < w[440] < 0.001 -0.001 < w[441] < 0.001 -0.001 < w[442] < 0.001 -0.001 < w[443] < 0.001 -0.001 < w[444] < 0.001 -0.001 < w[445] < 0.001 -0.001 < w[446] < 0.001 -0.001 < w[447] < 0.001 -0.001 < w[448] < 0.001 -0.001 < w[449] < 0.001 -0.001 < w[450] < 0.001 -0.001 < w[451] < 0.001 -0.001 < w[452] < 0.001 -0.001 < w[453] < 0.001 -0.001 < w[454] < 0.001 -0.001 < w[455] < 0.001 -0.001 < w[456] < 0.001 -0.001 < w[457] < 0.001 -0.001 < w[458] < 0.001 -0.001 < w[459] < 0.001 -0.001 < w[460] < 0.001 -0.001 < w[461] < 0.001 -0.001 < w[462] < 0.001 -0.001 < w[463] < 0.001 -0.001 < w[464] < 0.001 -0.001 < w[465] < 0.001 -0.001 < w[466] < 0.001 -0.001 < w[467] < 0.001 -0.001 < | w[468] | < 0.001 -0.001 < | w[469] | < 0.001 -0.001 < | w[470] | < 0.001 -0.001 < | w[471] | < 0.001 -0.001 < | w[472] | < 0.001 -0.001 < | w[473] | < 0.001 -0.001 < | w[474] | < 0.001 -0.001 < | w[475] | < 0.001 -0.001 < | w[476] | < 0.001 -0.001 < | w[477] | < 0.001 -0.001 < | w[478] | < 0.001 0.000 < | w[479] | < 0.002 -0.001 < | w[480] | < 0.001 -0.001 < | w[481] | < 0.001 -0.001 < | w[482] | < 0.001 -0.001 < | w[483] | < 0.001 -0.001 < | w[484] | < 0.001 -0.001 < | w[485] | < 0.001 -0.001 < | w[486] | < 0.001 -0.001 < | w[487] | < 0.001 -0.001 < | w[488] | < 0.001 -0.001 < | w[489] | < 0.001 -0.001 < | w[490] | < 0.001 -0.001 < | w[491] | < 0.001 -0.001 < | w[492] | < 0.001 -0.001 < | w[493] | < 0.001 -0.001 < | w[494] | < 0.001 -0.001 < | w[495] | < 0.001 -0.001 < | w[496] | < 0.001 -0.001 < | w[497] | < 0.001 -0.001 < | w[498] | < 0.001 -0.001 < | w[499] | < 0.001 -0.001 < | w[500] | < 0.001 -0.001 < | w[501] | < 0.001 -0.001 < | w[502] | < 0.001 -0.001 < | w[503] | < 0.001 -0.001 < | w[504] | < 0.001 -0.001 < | w[505] | < 0.001 -0.001 < w[506] < 0.001 -0.001 < w[507] < 0.001 -0.001 < w[508] < 0.001 -0.001 < w[509] < 0.001 -0.001 < w[510] < 0.001 -0.001 < w[511] < 0.001 -0.001 < w[512] < 0.001 -0.001 < w[513] < 0.001 -0.001 < w[514] < 0.001 -0.001 < w[515] < 0.001 -0.001 < w[516] < 0.001 -0.001 < w[517] < 0.001 -0.001 < w[518] < 0.001 -0.001 < w[519] < 0.001 -0.001 < w[520] < 0.001 -0.001 < w[521] < 0.001 -0.001 < w[522] < 0.001 -0.001 < w[523] < 0.001 -0.001 < w[524] < 0.001 -0.001 < w[525] < 0.001 -0.001 < w[526] < 0.001 -0.001 < w[527] < 0.001 -0.001 < w[528] < 0.001 -0.001 < w[529] < 0.001 -0.001 < w[530] < 0.001 -0.001 < w[531] < 0.001 -0.001 < w[532] < 0.001 -0.001 < w[533] < 0.001 -0.001 < w[534] < 0.001 -0.001 < w[535] < 0.001 -0.001 < w[536] < 0.001 -0.001 < w[537] < 0.001 -0.001 < w[538] < 0.001 -0.001 < w[539] < 0.001 -0.001 < w[540] < 0.001 -0.001 < w[541] < 0.001 -0.001 < w[542] < 0.001 -0.001 < w[543] < 0.001 -0.001 < w[544] < 0.001 -0.001 < w[545] < 0.001 -0.001 < w[546] < 0.001 -0.001 < w[547] < 0.001 -0.001 < w[548] < 0.001 -0.001 < w[549] < 0.001 -0.001 < w[550] < 0.001 -0.001 < w[551] < 0.001 -0.001 < w[552] < 0.001 -0.001 < w[553] < 0.001 -0.001 < w[554] < 0.001 -0.001 < w[555] < 0.001 -0.001 < w[556] < 0.001 -0.001 < w[557] < 0.001 -0.001 < w[558] < 0.001 -0.001 < w[559] < 0.001 -0.001 < w[560] < 0.001 -0.001 < w[561] < 0.001 -0.001 < w[562] < 0.001 -0.001 < w[563] < 0.001 -0.001 < w[564] < 0.001 -0.001 < w[565] < 0.001 -0.001 < w[566] < 0.001 -0.001 < w[567] < 0.001 -0.001 < w[568] < 0.001 -0.001 < w[569] < 0.001 -0.001 < w[570] < 0.001 -0.001 < w[571] < 0.001 -0.001 < w[572] < 0.001 -0.001 < w[573] < 0.001 -0.001 < w[574] < 0.001 -0.001 < w[575] < 0.001 -0.001 < w[576] < 0.001 -0.001 < w[577] < 0.001 -0.001 < w[578] < 0.001 -0.001 < w[579] < 0.001 -0.001 < w[580] < 0.001 -0.001 < w[581] < 0.001 -0.001 < w[582] < 0.001 -0.001 < w[583] < 0.001 -0.001 < w[584] < 0.001 -0.001 < w[585] < 0.001 -0.001 < w[586] < 0.001 -0.001 < w[587] < 0.001 -0.001 < w[588] < 0.001 -0.001 < w[589] < 0.001 -0.001 < w[590] < 0.001 -0.001 < w[591] < 0.001 -0.001 < w[592] < 0.001 -0.001 < w[593] < 0.001 -0.001 < w[594] < 0.001 -0.001 < w[595] < 0.001 -0.001 < w[596] < 0.001 -0.001 < w[597] < 0.001 -0.001 < w[598] < 0.001 -0.001 < w[599] < 0.001 -0.001 < w[600] < 0.001 -0.001 < w[601] < 0.001 -0.001 < w[602] < 0.001 -0.001 < w[603] < 0.001 -0.001 < w[604] < 0.001 -0.001 < w[605] < 0.001 -0.001 < w[606] < 0.001 -0.001 < w[607] < 0.001 -0.001 < w[608] < 0.001 -0.001 < w[609] < 0.001 -0.001 < w[610] < 0.001 -0.001 < w[611] < 0.001 -0.001 < w[612] < 0.001 -0.001 < w[613] < 0.001 -0.001 < w[614] < 0.001 -0.001 < w[615] < 0.001 -0.001 < w[616] < 0.001 -0.001 < w[617] < 0.001 -0.001 < w[618] < 0.001 -0.001 < w[619] < 0.001 -0.001 < | w[620] | < 0.001 -0.001 < | w[621] | < 0.001 -0.001 < | w[622] | < 0.001 -0.001 < | w[623] | < 0.001 -0.001 < | w[624] | < 0.001 -0.001 < | w[625] | < 0.001 -0.001 < | w[626] | < 0.001 -0.001 < | w[627] | < 0.001 -0.001 < | w[628] | < 0.001 -0.001 < | w[629] | < 0.001 -0.001 < | w[630] | < 0.001 -0.001 < | w[631] | < 0.001 -0.001 < | w[632] | < 0.001 -0.001 < | w[633] | < 0.001 -0.001 < | w[634] | < 0.001 -0.001 < | w[635] | < 0.001 -0.001 < | w[636] | < 0.001 -0.001 < | w[637] | < 0.001 -0.001 < | w[638] | < 0.001 -0.001 < | w[639] | < 0.001
  7. 7. Method for generating complex audio sub-band values in audio sub-band channels characterized by comprising: windowing an audio input sample frame in the time domain that is in a temporal sequence extending from an older sample to a newer sample using an analysis window function comprising a first group of window coefficients comprising a first portion of the window coefficient sequence and a second group of window coefficients comprising a second portion of the window coefficient sequence, wherein the first portion comprises smaller window coefficients than the second portion, wherein a total energy value of the window coefficients in the first portion is greater than a total energy value of the window coefficients in the second portion, wherein the first group of window coefficients is used for windowing newer time-domain samples and the second group of window coefficients is used for windowing older time-domain samples, calculating the audio sub-band values using the windowed samples, wherein calculating comprises time/frequency conversion of the sub-band values. audio such that all sub-band values based on a windowed sample frame represent a spectral representation of the windowed samples of the windowed sample frame, and wherein the time/frequency conversion of audio sub-band values comprises generating complex audio sub-band values.
  8. 8. A non-transient storage medium characterized by having stored within it a set of instructions to execute, when running on a processor, a method for generating complex audio sub-band values in channels, wherein the method comprises: windowing a frame of audio input samples in the time domain that is in a temporal sequence extending from an older sample to a more recent sample using an analysis window function comprising a first group of window coefficients comprising a first portion of the window coefficient sequence and a second group of window coefficients comprising a second portion of the window coefficient sequence, wherein the first portion comprises smaller window coefficients than the second portion, wherein a total energy value of the window coefficients in the first portion is greater than a total energy value of the window coefficients in the second portion, wherein the first group of window coefficients is used for windowing more recent samples in the time domain and the second group of window coefficients is used for windowing older samples in the time domain, calculating the audio sub-band values using windowed samples, wherein calculation comprises time/frequency conversion of audio sub-band values such that all sub-band values based on a windowed sample frame represent a spectral representation of the windowed samples of the windowed sample frame, and wherein time/frequency conversion of audio sub-band values comprises generating complex audio sub-band values.

Description

Technical Field The configurations of the present invention relate to apparatus and a method for generating audio sub-band values, apparatus and a method for generating time-domain audio samples, and systems comprising any of the aforementioned apparatus that may, for example, be implemented in the field of audio encoding, audio decoding, or other modern applications related to audio transmission. Modern digital audio processing is typically based on encoding schemes that enable a significant reduction in bit rates, transmission bandwidth, and storage space compared to direct transmission or storage of the respective audio data. This is achieved by encoding the audio data on the transmitter side and decoding the encoded data on the receiver side before, for example, providing the decoded audio data to a listener or other signal processing. Such digital audio processing systems can be implemented, on the one hand, with respect to a wide variety of parameters, typically influencing the quality of the transmitted or otherwise processed audio data, and, on the other hand, with respect to computational efficiency, bandwidth, and other performance-related parameters. Very often, superior quality requires higher bit rates, high computational complexity, and a greater storage requirement for the corresponding encoded audio data. Therefore, depending on the application in mind, factors such as permissible bit rates, acceptable computational complexity, and acceptable amounts of data must be balanced with desirable and attainable quality. Another parameter, which is especially important in real-time applications such as bidirectional or unidirectional communication, is the delay imposed by different encoding schemes. Consequently, the delay imposed by audio encoding and decoding represents another constraint in terms of the previously mentioned parameters when weighing the needs and costs of different encoding schemes with a specific application field in mind. Since such digital audio systems can be applied in many different fields of application, from ultra-low quality transmissions to the most sophisticated transmissions, different parameters and different constraints are quite frequently imposed on the respective audio systems. In some applications, a lower delay may, for example, require a higher bit rate, and therefore a higher transmission bandwidth, compared to an audio system with a higher delay, but with a comparable quality level. However, in many cases, there may be a need to make compromises in terms of different parameters such as bit rate, computational complexity, memory requirements, quality, and latency. Summary A configuration of an apparatus for generating audio sub-band values in audio sub-band channels comprises an analysis windower for working with windows in a time-domain audio input sample frame being in a time sequence extending from a previous sample to a subsequent sample using an analysis window function comprising a sequence of window coefficients to obtain windowed samples. The analysis window function comprises a first group of window coefficients comprising a first portion of the window coefficient sequence and a second group of window coefficients comprising a second portion of the window coefficient sequence, wherein the first portion comprises fewer window coefficients than the second portion and wherein the energy value of the window coefficients in the first portion is greater than the energy value of the window coefficients in the second portion. The first group of window coefficients is used for subsequent time-domain samples for working with windows and the second group of window coefficients is used for previous time-domain samples for working with windows. Furthermore, the configuration includes a calculator for calculating audio sub-band values using windowed samples. A configuration of an apparatus for generating time-domain audio samples comprises a calculator for calculating a sequence of intermediate time-domain samples from audio sub-band values in audio sub-band channels, wherein the sequence comprises previous intermediate time-domain samples and subsequent intermediate time-domain samples. Furthermore, a configuration of the apparatus comprises a [synthesis windower] for windowing the sequence of intermediate time-domain samples using a synthesis window function, comprising a sequence of window coefficients for obtaining windowed intermediate time-domain samples, wherein the synthesis window function comprises a first group of window coefficients comprising a first portion of the window coefficient sequence and a second group of window coefficients comprising a second portion of the window coefficient sequence. The first portion comprises fewer window coefficients than the second portion, and the energy value of the window coefficients in the first portion is higher than the energy value of the window coefficients in the second portion. The first group of window coef