Mercurial > SDL_sound_CoreAudio
annotate decoders/mpglib/layer2.c @ 439:48b56888964d
Updated.
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Sun, 12 Jan 2003 21:12:19 +0000 |
| parents | ad4c8f34136a |
| children |
| rev | line source |
|---|---|
| 261 | 1 /* |
| 2 * Mpeg Layer-2 audio decoder | |
| 3 * -------------------------- | |
| 4 * copyright (c) 1995 by Michael Hipp, All rights reserved. See also 'README' | |
| 5 * | |
| 6 */ | |
| 7 | |
| 8 #include "mpg123_sdlsound.h" | |
| 9 #include "l2tables.h" | |
| 10 | |
| 11 static int grp_3tab[32 * 3] = { 0, }; /* used: 27 */ | |
| 12 static int grp_5tab[128 * 3] = { 0, }; /* used: 125 */ | |
| 13 static int grp_9tab[1024 * 3] = { 0, }; /* used: 729 */ | |
| 14 | |
| 15 real muls[27][64]; /* also used by layer 1 */ | |
| 16 | |
| 17 void init_layer2(void) | |
| 18 { | |
| 19 static double mulmul[27] = { | |
| 20 0.0 , -2.0/3.0 , 2.0/3.0 , | |
| 21 2.0/7.0 , 2.0/15.0 , 2.0/31.0, 2.0/63.0 , 2.0/127.0 , 2.0/255.0 , | |
| 22 2.0/511.0 , 2.0/1023.0 , 2.0/2047.0 , 2.0/4095.0 , 2.0/8191.0 , | |
| 23 2.0/16383.0 , 2.0/32767.0 , 2.0/65535.0 , | |
| 24 -4.0/5.0 , -2.0/5.0 , 2.0/5.0, 4.0/5.0 , | |
| 25 -8.0/9.0 , -4.0/9.0 , -2.0/9.0 , 2.0/9.0 , 4.0/9.0 , 8.0/9.0 }; | |
| 26 static int base[3][9] = { | |
| 27 { 1 , 0, 2 , } , | |
| 28 { 17, 18, 0 , 19, 20 , } , | |
| 29 { 21, 1, 22, 23, 0, 24, 25, 2, 26 } }; | |
| 30 int i,j,k,l,len; | |
| 31 real *table; | |
| 32 static int tablen[3] = { 3 , 5 , 9 }; | |
| 33 static int *itable,*tables[3] = { grp_3tab , grp_5tab , grp_9tab }; | |
| 34 | |
| 35 for(i=0;i<3;i++) | |
| 36 { | |
| 37 itable = tables[i]; | |
| 38 len = tablen[i]; | |
| 39 for(j=0;j<len;j++) | |
| 40 for(k=0;k<len;k++) | |
| 41 for(l=0;l<len;l++) | |
| 42 { | |
| 43 *itable++ = base[i][l]; | |
| 44 *itable++ = base[i][k]; | |
| 45 *itable++ = base[i][j]; | |
| 46 } | |
| 47 } | |
| 48 | |
| 49 for(k=0;k<27;k++) | |
| 50 { | |
| 51 double m=mulmul[k]; | |
| 52 table = muls[k]; | |
| 53 for(j=3,i=0;i<63;i++,j--) | |
| 54 *table++ = m * pow(2.0,(double) j / 3.0); | |
| 55 *table++ = 0.0; | |
| 56 } | |
| 57 } | |
| 58 | |
| 59 | |
| 60 void II_step_one(unsigned int *bit_alloc,int *scale,struct frame *fr) | |
| 61 { | |
| 62 int stereo = fr->stereo-1; | |
| 63 int sblimit = fr->II_sblimit; | |
| 64 int jsbound = fr->jsbound; | |
| 65 int sblimit2 = fr->II_sblimit<<stereo; | |
| 66 struct al_table *alloc1 = fr->alloc; | |
| 67 int i; | |
| 68 static unsigned int scfsi_buf[64]; | |
| 69 unsigned int *scfsi,*bita; | |
| 70 int sc,step; | |
| 71 | |
| 72 bita = bit_alloc; | |
| 73 if(stereo) | |
| 74 { | |
| 75 for (i=jsbound;i;i--,alloc1+=(1<<step)) | |
| 76 { | |
| 77 *bita++ = (char) getbits(step=alloc1->bits); | |
| 78 *bita++ = (char) getbits(step); | |
| 79 } | |
| 80 for (i=sblimit-jsbound;i;i--,alloc1+=(1<<step)) | |
| 81 { | |
| 82 bita[0] = (char) getbits(step=alloc1->bits); | |
| 83 bita[1] = bita[0]; | |
| 84 bita+=2; | |
| 85 } | |
| 86 bita = bit_alloc; | |
| 87 scfsi=scfsi_buf; | |
| 88 for (i=sblimit2;i;i--) | |
| 89 if (*bita++) | |
| 90 *scfsi++ = (char) getbits_fast(2); | |
| 91 } | |
| 92 else /* mono */ | |
| 93 { | |
| 94 for (i=sblimit;i;i--,alloc1+=(1<<step)) | |
| 95 *bita++ = (char) getbits(step=alloc1->bits); | |
| 96 bita = bit_alloc; | |
| 97 scfsi=scfsi_buf; | |
| 98 for (i=sblimit;i;i--) | |
| 99 if (*bita++) | |
| 100 *scfsi++ = (char) getbits_fast(2); | |
| 101 } | |
| 102 | |
| 103 bita = bit_alloc; | |
| 104 scfsi=scfsi_buf; | |
| 105 for (i=sblimit2;i;i--) | |
| 106 if (*bita++) | |
| 107 switch (*scfsi++) | |
| 108 { | |
| 109 case 0: | |
| 110 *scale++ = getbits_fast(6); | |
| 111 *scale++ = getbits_fast(6); | |
| 112 *scale++ = getbits_fast(6); | |
| 113 break; | |
| 114 case 1 : | |
| 115 *scale++ = sc = getbits_fast(6); | |
| 116 *scale++ = sc; | |
| 117 *scale++ = getbits_fast(6); | |
| 118 break; | |
| 119 case 2: | |
| 120 *scale++ = sc = getbits_fast(6); | |
| 121 *scale++ = sc; | |
| 122 *scale++ = sc; | |
| 123 break; | |
| 124 default: /* case 3 */ | |
| 125 *scale++ = getbits_fast(6); | |
| 126 *scale++ = sc = getbits_fast(6); | |
| 127 *scale++ = sc; | |
| 128 break; | |
| 129 } | |
| 130 | |
| 131 } | |
| 132 | |
| 133 void II_step_two(unsigned int *bit_alloc,real fraction[2][4][SBLIMIT],int *scale,struct frame *fr,int x1) | |
| 134 { | |
| 135 int i,j,k,ba; | |
| 136 int stereo = fr->stereo; | |
| 137 int sblimit = fr->II_sblimit; | |
| 138 int jsbound = fr->jsbound; | |
| 139 struct al_table *alloc2,*alloc1 = fr->alloc; | |
| 140 unsigned int *bita=bit_alloc; | |
| 141 int d1,step; | |
| 142 | |
| 143 for (i=0;i<jsbound;i++,alloc1+=(1<<step)) | |
| 144 { | |
| 145 step = alloc1->bits; | |
| 146 for (j=0;j<stereo;j++) | |
| 147 { | |
| 148 if ( (ba=*bita++) ) | |
| 149 { | |
| 150 k=(alloc2 = alloc1+ba)->bits; | |
| 151 if( (d1=alloc2->d) < 0) | |
| 152 { | |
| 153 real cm=muls[k][scale[x1]]; | |
| 154 fraction[j][0][i] = ((real) ((int)getbits(k) + d1)) * cm; | |
| 155 fraction[j][1][i] = ((real) ((int)getbits(k) + d1)) * cm; | |
| 156 fraction[j][2][i] = ((real) ((int)getbits(k) + d1)) * cm; | |
| 157 } | |
| 158 else | |
| 159 { | |
| 160 static int *table[] = { 0,0,0,grp_3tab,0,grp_5tab,0,0,0,grp_9tab }; | |
| 161 unsigned int idx,*tab,m=scale[x1]; | |
| 162 idx = (unsigned int) getbits(k); | |
| 163 tab = (unsigned int *) (table[d1] + idx + idx + idx); | |
| 164 fraction[j][0][i] = muls[*tab++][m]; | |
| 165 fraction[j][1][i] = muls[*tab++][m]; | |
| 166 fraction[j][2][i] = muls[*tab][m]; | |
| 167 } | |
| 168 scale+=3; | |
| 169 } | |
| 170 else | |
| 171 fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = 0.0; | |
| 172 } | |
| 173 } | |
| 174 | |
| 175 for (i=jsbound;i<sblimit;i++,alloc1+=(1<<step)) | |
| 176 { | |
| 177 step = alloc1->bits; | |
| 178 bita++; /* channel 1 and channel 2 bitalloc are the same */ | |
| 179 if ( (ba=*bita++) ) | |
| 180 { | |
| 181 k=(alloc2 = alloc1+ba)->bits; | |
| 182 if( (d1=alloc2->d) < 0) | |
| 183 { | |
| 184 real cm; | |
| 185 cm=muls[k][scale[x1+3]]; | |
| 186 fraction[1][0][i] = (fraction[0][0][i] = (real) ((int)getbits(k) + d1) ) * cm; | |
| 187 fraction[1][1][i] = (fraction[0][1][i] = (real) ((int)getbits(k) + d1) ) * cm; | |
| 188 fraction[1][2][i] = (fraction[0][2][i] = (real) ((int)getbits(k) + d1) ) * cm; | |
| 189 cm=muls[k][scale[x1]]; | |
| 190 fraction[0][0][i] *= cm; fraction[0][1][i] *= cm; fraction[0][2][i] *= cm; | |
| 191 } | |
| 192 else | |
| 193 { | |
| 194 static int *table[] = { 0,0,0,grp_3tab,0,grp_5tab,0,0,0,grp_9tab }; | |
| 195 unsigned int idx,*tab,m1,m2; | |
| 196 m1 = scale[x1]; m2 = scale[x1+3]; | |
| 197 idx = (unsigned int) getbits(k); | |
| 198 tab = (unsigned int *) (table[d1] + idx + idx + idx); | |
| 199 fraction[0][0][i] = muls[*tab][m1]; fraction[1][0][i] = muls[*tab++][m2]; | |
| 200 fraction[0][1][i] = muls[*tab][m1]; fraction[1][1][i] = muls[*tab++][m2]; | |
| 201 fraction[0][2][i] = muls[*tab][m1]; fraction[1][2][i] = muls[*tab][m2]; | |
| 202 } | |
| 203 scale+=6; | |
| 204 } | |
| 205 else { | |
| 206 fraction[0][0][i] = fraction[0][1][i] = fraction[0][2][i] = | |
| 207 fraction[1][0][i] = fraction[1][1][i] = fraction[1][2][i] = 0.0; | |
| 208 } | |
| 209 /* | |
| 210 should we use individual scalefac for channel 2 or | |
| 211 is the current way the right one , where we just copy channel 1 to | |
| 212 channel 2 ?? | |
| 213 The current 'strange' thing is, that we throw away the scalefac | |
| 214 values for the second channel ...!! | |
| 215 -> changed .. now we use the scalefac values of channel one !! | |
| 216 */ | |
| 217 } | |
| 218 | |
| 219 for(i=sblimit;i<SBLIMIT;i++) | |
| 220 for (j=0;j<stereo;j++) | |
| 221 fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = 0.0; | |
| 222 | |
| 223 } | |
| 224 | |
| 225 static void II_select_table(struct frame *fr) | |
| 226 { | |
| 227 static int translate[3][2][16] = | |
| 228 { { { 0,2,2,2,2,2,2,0,0,0,1,1,1,1,1,0 } , | |
| 229 { 0,2,2,0,0,0,1,1,1,1,1,1,1,1,1,0 } } , | |
| 230 { { 0,2,2,2,2,2,2,0,0,0,0,0,0,0,0,0 } , | |
| 231 { 0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0 } } , | |
| 232 { { 0,3,3,3,3,3,3,0,0,0,1,1,1,1,1,0 } , | |
| 233 { 0,3,3,0,0,0,1,1,1,1,1,1,1,1,1,0 } } }; | |
| 234 | |
| 235 int table,sblim; | |
| 236 static struct al_table *tables[5] = | |
| 237 { alloc_0, alloc_1, alloc_2, alloc_3 , alloc_4 }; | |
| 238 static int sblims[5] = { 27 , 30 , 8, 12 , 30 }; | |
| 239 | |
| 240 if(fr->lsf) | |
| 241 table = 4; | |
| 242 else | |
| 243 table = translate[fr->sampling_frequency][2-fr->stereo][fr->bitrate_index]; | |
| 244 sblim = sblims[table]; | |
| 245 | |
| 246 fr->alloc = tables[table]; | |
| 247 fr->II_sblimit = sblim; | |
| 248 } | |
| 249 | |
|
281
ad4c8f34136a
Minor formatting updates.
Ryan C. Gordon <icculus@icculus.org>
parents:
279
diff
changeset
|
250 int do_layer2(struct frame *fr,unsigned char *pcm_sample, |
|
ad4c8f34136a
Minor formatting updates.
Ryan C. Gordon <icculus@icculus.org>
parents:
279
diff
changeset
|
251 int *pcm_point,struct mpstr *mp) |
| 261 | 252 { |
| 253 int clip=0; | |
| 254 int i,j; | |
| 255 int stereo = fr->stereo; | |
| 256 real fraction[2][4][SBLIMIT]; /* pick_table clears unused subbands */ | |
| 257 unsigned int bit_alloc[64]; | |
| 258 int scale[192]; | |
| 259 int single = fr->single; | |
| 260 | |
| 261 II_select_table(fr); | |
| 262 fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ? | |
| 263 (fr->mode_ext<<2)+4 : fr->II_sblimit; | |
| 264 | |
| 265 if(stereo == 1 || single == 3) | |
| 266 single = 0; | |
| 267 | |
| 268 II_step_one(bit_alloc, scale, fr); | |
| 269 | |
| 270 for (i=0;i<SCALE_BLOCK;i++) | |
| 271 { | |
| 272 II_step_two(bit_alloc,fraction,scale,fr,i>>2); | |
| 273 for (j=0;j<3;j++) { | |
| 274 if(single >= 0) { | |
|
279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
275 clip += synth_1to1_mono(fraction[0][j],pcm_sample,pcm_point,mp); |
| 261 | 276 } |
| 277 else { | |
| 278 int p1 = *pcm_point; | |
|
279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
279 clip += synth_1to1(fraction[0][j],0,pcm_sample,&p1,mp); |
|
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
280 clip += synth_1to1(fraction[1][j],1,pcm_sample,pcm_point,mp); |
| 261 | 281 } |
| 282 | |
| 283 } | |
| 284 } | |
| 285 | |
| 286 return clip; | |
| 287 } | |
| 288 | |
| 289 |