1 /* 2 decode_i486.c: i486 decode 3 4 copyright 1998-2006 by the mpg123 project - free software under the terms of the LGPL 2.1 5 see COPYING and AUTHORS files in distribution or http://mpg123.org 6 initially written by Fabrice Bellard 7 8 One has to see if the modification for non-static memory kills this optimization (cache locality?). 9 */ 10 11 /* 12 * Subband Synthesis for MPEG Audio. 13 * 14 * Version optimized for 80486 by using integer arithmetic, 15 * multiplications by shift and add, and by increasing locality in 16 * order to fit the 8KB L1 cache. This code should be compiled with gcc 17 * 2.7.2 or higher. 18 * 19 * Note: this version does not guaranty a good accuracy. The filter 20 * coefficients are quantified on 14 bits. 21 * 22 * (c) 1998 Fabrice Bellard 23 */ 24 25 #include "mpg123lib_intern.h" 26 27 #define FIR16_1(pos,c0,c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11,c12,c13,c14,c15) \ 28 {\ 29 int sum;\ 30 sum=(c0)*b0[0]+(c1)*b0[1]+(c2)*b0[2]+(c3)*b0[3]+\ 31 (c4)*b0[4]+(c5)*b0[5]+(c6)*b0[6]+(c7)*b0[7]+\ 32 (c8)*b0[8]+(c9)*b0[9]+(c10)*b0[10]+(c11)*b0[11]+\ 33 (c12)*b0[12]+(c13)*b0[13]+(c14)*b0[14]+(c15)*b0[15];\ 34 sum=(sum+(1 << 13))>>14;\ 35 if (sum<-32768) sum=-32768;\ 36 else if (sum>32767) sum=32767;\ 37 samples[2*(pos)]=sum;\ 38 b0+=FIR_BUFFER_SIZE;\ 39 } 40 41 #define FIR16_2(pos1,c0,c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11,c12,c13,c14,c15,\ 42 pos2,d0,d1,d2,d3,d4,d5,d6,d7,d8,d9,d10,d11,d12,d13,d14,d15) \ 43 {\ 44 int sum1,sum2,v;\ 45 \ 46 v=b0[0];\ 47 sum1=(c0)*v;\ 48 sum2=(d0)*v;\ 49 v=b0[1];\ 50 sum1+=(c1)*v;\ 51 sum2+=(d1)*v;\ 52 v=b0[2];\ 53 sum1+=(c2)*v;\ 54 sum2+=(d2)*v;\ 55 v=b0[3];\ 56 sum1+=(c3)*v;\ 57 sum2+=(d3)*v;\ 58 v=b0[4];\ 59 sum1+=(c4)*v;\ 60 sum2+=(d4)*v;\ 61 v=b0[5];\ 62 sum1+=(c5)*v;\ 63 sum2+=(d5)*v;\ 64 v=b0[6];\ 65 sum1+=(c6)*v;\ 66 sum2+=(d6)*v;\ 67 v=b0[7];\ 68 sum1+=(c7)*v;\ 69 sum2+=(d7)*v;\ 70 v=b0[8];\ 71 sum1+=(c8)*v;\ 72 sum2+=(d8)*v;\ 73 v=b0[9];\ 74 sum1+=(c9)*v;\ 75 sum2+=(d9)*v;\ 76 v=b0[10];\ 77 sum1+=(c10)*v;\ 78 sum2+=(d10)*v;\ 79 v=b0[11];\ 80 sum1+=(c11)*v;\ 81 sum2+=(d11)*v;\ 82 v=b0[12];\ 83 sum1+=(c12)*v;\ 84 sum2+=(d12)*v;\ 85 v=b0[13];\ 86 sum1+=(c13)*v;\ 87 sum2+=(d13)*v;\ 88 v=b0[14];\ 89 sum1+=(c14)*v;\ 90 sum2+=(d14)*v;\ 91 v=b0[15];\ 92 sum1+=(c15)*v;\ 93 sum2+=(d15)*v;\ 94 \ 95 sum1=(sum1+(1<<13))>>14;\ 96 sum2=(sum2+(1<<13))>>14;\ 97 \ 98 if (sum1<-32768) sum1=-32768;\ 99 else if (sum1>32767) sum1=32767;\ 100 samples[(pos1)*2]=sum1;\ 101 \ 102 if (sum2<-32768) sum2=-32768;\ 103 else if (sum2>32767) sum2=32767;\ 104 samples[(pos2)*2]=sum2;\ 105 b0+=FIR_BUFFER_SIZE;\ 106 } 107 108 int absynth_1to1_i486(real *bandPtr, int channel, mpg123_handle *fr, int nb_blocks) 109 { 110 short *samples = (short *) (fr->buffer.data+fr->buffer.fill); 111 int *b0,**buf; 112 int clip = 0; 113 int block,b,bo_start; 114 115 /* samples address */ 116 samples+=channel; 117 118 bo_start=fr->i486bo[channel]; 119 buf = fr->int_buffs[channel]; 120 121 b=bo_start; 122 for(block=0;block<nb_blocks;block++) { 123 124 /* FIR offset */ 125 b++; 126 if (b >= FIR_BUFFER_SIZE) { 127 int *p,*q; 128 int c,i,j; 129 130 /* we shift the buffers */ 131 for(c=0;c<2;c++) { 132 p=&buf[c][0]+1; 133 q=p+(FIR_BUFFER_SIZE-FIR_SIZE); 134 for(i=0;i<17;i++) { 135 for(j=0;j<FIR_SIZE-1;j++) p[j]=q[j]; 136 p+=FIR_BUFFER_SIZE; 137 q+=FIR_BUFFER_SIZE; 138 } 139 } 140 /* we update 'bo' accordingly */ 141 b=fr->i486bo[channel]=FIR_SIZE; 142 } 143 144 if(b & 1) { 145 dct64_i486(buf[1]+b,buf[0]+b,bandPtr); 146 } else { 147 dct64_i486(buf[0]+b,buf[1]+b,bandPtr); 148 } 149 bandPtr+=32; 150 } 151 fr->i486bo[channel]=b; 152 153 /* filter bank: part 1 */ 154 b=bo_start; 155 for(block=0;block<nb_blocks;block++) { 156 b++; 157 if (b >= FIR_BUFFER_SIZE) b=FIR_SIZE; 158 if(b & 1) { 159 b0 = buf[0] + b - (FIR_SIZE-1); 160 } else { 161 b0 = buf[1] + b - (FIR_SIZE-1); 162 } 163 164 FIR16_1(0,-7,53,-114,509,-1288,1643,-9372,18759,9372,1643,1288,509,114,53,7,0); 165 FIR16_2(1,-6,52,-100,515,-1197,1783,-8910,18748,9834,1489,1379,500,129,54,7,0, 166 31,0,-7,54,-129,500,-1379,1489,-9834,18748,8910,1783,1197,515,100,52,6); 167 FIR16_2(2,-6,50,-86,520,-1106,1910,-8447,18714,10294,1322,1469,488,145,55,8,0, 168 30,0,-8,55,-145,488,-1469,1322,-10294,18714,8447,1910,1106,520,86,50,6); 169 FIR16_2(3,-5,49,-73,521,-1015,2023,-7986,18657,10751,1140,1559,473,161,56,9,0, 170 29,0,-9,56,-161,473,-1559,1140,-10751,18657,7986,2023,1015,521,73,49,5); 171 samples+=64; 172 } 173 samples-=64*nb_blocks; 174 175 /* filter bank: part 2 */ 176 177 b=bo_start; 178 for(block=0;block<nb_blocks;block++) { 179 b++; 180 if (b >= FIR_BUFFER_SIZE) b=FIR_SIZE; 181 if(b & 1) { 182 b0 = buf[0] + b - (FIR_SIZE-1) + 4*FIR_BUFFER_SIZE; 183 } else { 184 b0 = buf[1] + b - (FIR_SIZE-1) + 4*FIR_BUFFER_SIZE; 185 } 186 187 FIR16_2(4,-4,47,-61,521,-926,2123,-7528,18578,11205,944,1647,455,177,56,10,0, 188 28,0,-10,56,-177,455,-1647,944,-11205,18578,7528,2123,926,521,61,47,4); 189 FIR16_2(5,-4,45,-49,518,-837,2210,-7072,18477,11654,733,1733,434,194,57,11,0, 190 27,0,-11,57,-194,434,-1733,733,-11654,18477,7072,2210,837,518,49,45,4); 191 FIR16_2(6,-4,44,-38,514,-751,2284,-6620,18353,12097,509,1817,411,212,57,12,0, 192 26,0,-12,57,-212,411,-1817,509,-12097,18353,6620,2284,751,514,38,44,4); 193 FIR16_2(7,-3,42,-27,508,-665,2347,-6173,18208,12534,270,1899,383,229,56,13,0, 194 25,0,-13,56,-229,383,-1899,270,-12534,18208,6173,2347,665,508,27,42,3); 195 196 samples+=64; 197 } 198 samples-=64*nb_blocks; 199 200 /* filter bank: part 3 */ 201 202 b=bo_start; 203 for(block=0;block<nb_blocks;block++) { 204 b++; 205 if (b >= FIR_BUFFER_SIZE) b=FIR_SIZE; 206 if(b & 1) { 207 b0 = buf[0] + b - (FIR_SIZE-1) + 8*FIR_BUFFER_SIZE; 208 } else { 209 b0 = buf[1] + b - (FIR_SIZE-1) + 8*FIR_BUFFER_SIZE; 210 } 211 212 FIR16_2(8,-3,40,-18,500,-582,2398,-5732,18042,12963,17,1977,353,247,56,14,0, 213 24,0,-14,56,-247,353,-1977,17,-12963,18042,5732,2398,582,500,18,40,3); 214 FIR16_2(9,-2,38,-9,490,-501,2437,-5297,17855,13383,-249,2052,320,266,55,15,0, 215 23,0,-15,55,-266,320,-2052,-249,-13383,17855,5297,2437,501,490,9,38,2); 216 FIR16_2(10,-2,36,0,479,-423,2465,-4869,17647,13794,-530,2122,282,284,53,17,0, 217 22,0,-17,53,-284,282,-2122,-530,-13794,17647,4869,2465,423,479,0,36,2); 218 FIR16_2(11,-2,34,7,467,-347,2483,-4449,17419,14194,-825,2188,242,302,52,18,0, 219 21,0,-18,52,-302,242,-2188,-825,-14194,17419,4449,2483,347,467,-7,34,2); 220 221 samples+=64; 222 } 223 samples-=64*nb_blocks; 224 225 /* filter bank: part 4 */ 226 227 b=bo_start; 228 for(block=0;block<nb_blocks;block++) { 229 b++; 230 if (b >= FIR_BUFFER_SIZE) b=FIR_SIZE; 231 if(b & 1) { 232 b0 = buf[0] + b - (FIR_SIZE-1) + 12*FIR_BUFFER_SIZE; 233 } else { 234 b0 = buf[1] + b - (FIR_SIZE-1) + 12*FIR_BUFFER_SIZE; 235 } 236 237 FIR16_2(12,-2,33,14,454,-273,2491,-4038,17173,14583,-1133,2249,198,320,50,19,0, 238 20,0,-19,50,-320,198,-2249,-1133,-14583,17173,4038,2491,273,454,-14,33,2); 239 FIR16_2(13,-1,31,20,439,-203,2489,-3637,16907,14959,-1454,2304,151,339,47,21,-1, 240 19,-1,-21,47,-339,151,-2304,-1454,-14959,16907,3637,2489,203,439,-20,31,1); 241 FIR16_2(14,-1,29,26,424,-136,2479,-3245,16623,15322,-1788,2354,100,357,44,22,-1, 242 18,-1,-22,44,-357,100,-2354,-1788,-15322,16623,3245,2479,136,424,-26,29,1); 243 FIR16_2(15,-1,27,31,408,-72,2459,-2863,16322,15671,-2135,2396,46,374,40,24,-1, 244 17,-1,-24,40,-374,46,-2396,-2135,-15671,16322,2863,2459,72,408,-31,27,1); 245 FIR16_1(16,-1,0,36,0,-11,0,-2493,0,16004,0,2431,0,391,0,26,0); 246 247 samples+=64; 248 } 249 250 return clip; 251 } 252 253