1 /******************************************************************** 2 * * 3 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. * 4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS * 5 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE * 6 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. * 7 * * 8 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 * 9 * by the Xiph.Org Foundation http://www.xiph.org/ * 10 * * 11 ******************************************************************** 12 13 function: PCM data envelope analysis 14 last mod: $Id: envelope.c 16227 2009-07-08 06:58:46Z xiphmont $ 15 16 ********************************************************************/ 17 18 #include <stdlib.h> 19 #include <string.h> 20 #include <stdio.h> 21 #include <math.h> 22 #include <ogg/ogg.h> 23 #include "vorbis/codec.h" 24 #include "codec_internal.h" 25 26 #include "os.h" 27 #include "scales.h" 28 #include "envelope.h" 29 #include "mdct.h" 30 #include "misc.h" 31 32 void _ve_envelope_init(envelope_lookup *e,vorbis_info *vi){ 33 codec_setup_info *ci=vi->codec_setup; 34 vorbis_info_psy_global *gi=&ci->psy_g_param; 35 int ch=vi->channels; 36 int i,j; 37 int n=e->winlength=128; 38 e->searchstep=64; /* not random */ 39 40 e->minenergy=gi->preecho_minenergy; 41 e->ch=ch; 42 e->storage=128; 43 e->cursor=ci->blocksizes[1]/2; 44 e->mdct_win=_ogg_calloc(n,sizeof(*e->mdct_win)); 45 mdct_init(&e->mdct,n); 46 47 for(i=0;i<n;i++){ 48 e->mdct_win[i]=sin(i/(n-1.)*M_PI); 49 e->mdct_win[i]*=e->mdct_win[i]; 50 } 51 52 /* magic follows */ 53 e->band[0].begin=2; e->band[0].end=4; 54 e->band[1].begin=4; e->band[1].end=5; 55 e->band[2].begin=6; e->band[2].end=6; 56 e->band[3].begin=9; e->band[3].end=8; 57 e->band[4].begin=13; e->band[4].end=8; 58 e->band[5].begin=17; e->band[5].end=8; 59 e->band[6].begin=22; e->band[6].end=8; 60 61 for(j=0;j<VE_BANDS;j++){ 62 n=e->band[j].end; 63 e->band[j].window=_ogg_malloc(n*sizeof(*e->band[0].window)); 64 for(i=0;i<n;i++){ 65 e->band[j].window[i]=sin((i+.5)/n*M_PI); 66 e->band[j].total+=e->band[j].window[i]; 67 } 68 e->band[j].total=1./e->band[j].total; 69 } 70 71 e->filter=_ogg_calloc(VE_BANDS*ch,sizeof(*e->filter)); 72 e->mark=_ogg_calloc(e->storage,sizeof(*e->mark)); 73 74 } 75 76 void _ve_envelope_clear(envelope_lookup *e){ 77 int i; 78 mdct_clear(&e->mdct); 79 for(i=0;i<VE_BANDS;i++) 80 _ogg_free(e->band[i].window); 81 _ogg_free(e->mdct_win); 82 _ogg_free(e->filter); 83 _ogg_free(e->mark); 84 memset(e,0,sizeof(*e)); 85 } 86 87 /* fairly straight threshhold-by-band based until we find something 88 that works better and isn't patented. */ 89 90 static int _ve_amp(envelope_lookup *ve, 91 vorbis_info_psy_global *gi, 92 float *data, 93 envelope_band *bands, 94 envelope_filter_state *filters){ 95 long n=ve->winlength; 96 int ret=0; 97 long i,j; 98 float decay; 99 100 /* we want to have a 'minimum bar' for energy, else we're just 101 basing blocks on quantization noise that outweighs the signal 102 itself (for low power signals) */ 103 104 float minV=ve->minenergy; 105 float *vec=alloca(n*sizeof(*vec)); 106 107 /* stretch is used to gradually lengthen the number of windows 108 considered prevoius-to-potential-trigger */ 109 int stretch=max(VE_MINSTRETCH,ve->stretch/2); 110 float penalty=gi->stretch_penalty-(ve->stretch/2-VE_MINSTRETCH); 111 if(penalty<0.f)penalty=0.f; 112 if(penalty>gi->stretch_penalty)penalty=gi->stretch_penalty; 113 114 /*_analysis_output_always("lpcm",seq2,data,n,0,0, 115 totalshift+pos*ve->searchstep);*/ 116 117 /* window and transform */ 118 for(i=0;i<n;i++) 119 vec[i]=data[i]*ve->mdct_win[i]; 120 mdct_forward(&ve->mdct,vec,vec); 121 122 /*_analysis_output_always("mdct",seq2,vec,n/2,0,1,0); */ 123 124 /* near-DC spreading function; this has nothing to do with 125 psychoacoustics, just sidelobe leakage and window size */ 126 { 127 float temp=vec[0]*vec[0]+.7*vec[1]*vec[1]+.2*vec[2]*vec[2]; 128 int ptr=filters->nearptr; 129 130 /* the accumulation is regularly refreshed from scratch to avoid 131 floating point creep */ 132 if(ptr==0){ 133 decay=filters->nearDC_acc=filters->nearDC_partialacc+temp; 134 filters->nearDC_partialacc=temp; 135 }else{ 136 decay=filters->nearDC_acc+=temp; 137 filters->nearDC_partialacc+=temp; 138 } 139 filters->nearDC_acc-=filters->nearDC[ptr]; 140 filters->nearDC[ptr]=temp; 141 142 decay*=(1./(VE_NEARDC+1)); 143 filters->nearptr++; 144 if(filters->nearptr>=VE_NEARDC)filters->nearptr=0; 145 decay=todB(&decay)*.5-15.f; 146 } 147 148 /* perform spreading and limiting, also smooth the spectrum. yes, 149 the MDCT results in all real coefficients, but it still *behaves* 150 like real/imaginary pairs */ 151 for(i=0;i<n/2;i+=2){ 152 float val=vec[i]*vec[i]+vec[i+1]*vec[i+1]; 153 val=todB(&val)*.5f; 154 if(val<decay)val=decay; 155 if(val<minV)val=minV; 156 vec[i>>1]=val; 157 decay-=8.; 158 } 159 160 /*_analysis_output_always("spread",seq2++,vec,n/4,0,0,0);*/ 161 162 /* perform preecho/postecho triggering by band */ 163 for(j=0;j<VE_BANDS;j++){ 164 float acc=0.; 165 float valmax,valmin; 166 167 /* accumulate amplitude */ 168 for(i=0;i<bands[j].end;i++) 169 acc+=vec[i+bands[j].begin]*bands[j].window[i]; 170 171 acc*=bands[j].total; 172 173 /* convert amplitude to delta */ 174 { 175 int p,this=filters[j].ampptr; 176 float postmax,postmin,premax=-99999.f,premin=99999.f; 177 178 p=this; 179 p--; 180 if(p<0)p+=VE_AMP; 181 postmax=max(acc,filters[j].ampbuf[p]); 182 postmin=min(acc,filters[j].ampbuf[p]); 183 184 for(i=0;i<stretch;i++){ 185 p--; 186 if(p<0)p+=VE_AMP; 187 premax=max(premax,filters[j].ampbuf[p]); 188 premin=min(premin,filters[j].ampbuf[p]); 189 } 190 191 valmin=postmin-premin; 192 valmax=postmax-premax; 193 194 /*filters[j].markers[pos]=valmax;*/ 195 filters[j].ampbuf[this]=acc; 196 filters[j].ampptr++; 197 if(filters[j].ampptr>=VE_AMP)filters[j].ampptr=0; 198 } 199 200 /* look at min/max, decide trigger */ 201 if(valmax>gi->preecho_thresh[j]+penalty){ 202 ret|=1; 203 ret|=4; 204 } 205 if(valmin<gi->postecho_thresh[j]-penalty)ret|=2; 206 } 207 208 return(ret); 209 } 210 211 #if 0 212 static int seq=0; 213 static ogg_int64_t totalshift=-1024; 214 #endif 215 216 long _ve_envelope_search(vorbis_dsp_state *v){ 217 vorbis_info *vi=v->vi; 218 codec_setup_info *ci=vi->codec_setup; 219 vorbis_info_psy_global *gi=&ci->psy_g_param; 220 envelope_lookup *ve=((private_state *)(v->backend_state))->ve; 221 long i,j; 222 223 int first=ve->current/ve->searchstep; 224 int last=v->pcm_current/ve->searchstep-VE_WIN; 225 if(first<0)first=0; 226 227 /* make sure we have enough storage to match the PCM */ 228 if(last+VE_WIN+VE_POST>ve->storage){ 229 ve->storage=last+VE_WIN+VE_POST; /* be sure */ 230 ve->mark=_ogg_realloc(ve->mark,ve->storage*sizeof(*ve->mark)); 231 } 232 233 for(j=first;j<last;j++){ 234 int ret=0; 235 236 ve->stretch++; 237 if(ve->stretch>VE_MAXSTRETCH*2) 238 ve->stretch=VE_MAXSTRETCH*2; 239 240 for(i=0;i<ve->ch;i++){ 241 float *pcm=v->pcm[i]+ve->searchstep*(j); 242 ret|=_ve_amp(ve,gi,pcm,ve->band,ve->filter+i*VE_BANDS); 243 } 244 245 ve->mark[j+VE_POST]=0; 246 if(ret&1){ 247 ve->mark[j]=1; 248 ve->mark[j+1]=1; 249 } 250 251 if(ret&2){ 252 ve->mark[j]=1; 253 if(j>0)ve->mark[j-1]=1; 254 } 255 256 if(ret&4)ve->stretch=-1; 257 } 258 259 ve->current=last*ve->searchstep; 260 261 { 262 long centerW=v->centerW; 263 long testW= 264 centerW+ 265 ci->blocksizes[v->W]/4+ 266 ci->blocksizes[1]/2+ 267 ci->blocksizes[0]/4; 268 269 j=ve->cursor; 270 271 while(j<ve->current-(ve->searchstep)){/* account for postecho 272 working back one window */ 273 if(j>=testW)return(1); 274 275 ve->cursor=j; 276 277 if(ve->mark[j/ve->searchstep]){ 278 if(j>centerW){ 279 280 #if 0 281 if(j>ve->curmark){ 282 float *marker=alloca(v->pcm_current*sizeof(*marker)); 283 int l,m; 284 memset(marker,0,sizeof(*marker)*v->pcm_current); 285 fprintf(stderr,"mark! seq=%d, cursor:%fs time:%fs\n", 286 seq, 287 (totalshift+ve->cursor)/44100., 288 (totalshift+j)/44100.); 289 _analysis_output_always("pcmL",seq,v->pcm[0],v->pcm_current,0,0,totalshift); 290 _analysis_output_always("pcmR",seq,v->pcm[1],v->pcm_current,0,0,totalshift); 291 292 _analysis_output_always("markL",seq,v->pcm[0],j,0,0,totalshift); 293 _analysis_output_always("markR",seq,v->pcm[1],j,0,0,totalshift); 294 295 for(m=0;m<VE_BANDS;m++){ 296 char buf[80]; 297 sprintf(buf,"delL%d",m); 298 for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->filter[m].markers[l]*.1; 299 _analysis_output_always(buf,seq,marker,v->pcm_current,0,0,totalshift); 300 } 301 302 for(m=0;m<VE_BANDS;m++){ 303 char buf[80]; 304 sprintf(buf,"delR%d",m); 305 for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->filter[m+VE_BANDS].markers[l]*.1; 306 _analysis_output_always(buf,seq,marker,v->pcm_current,0,0,totalshift); 307 } 308 309 for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->mark[l]*.4; 310 _analysis_output_always("mark",seq,marker,v->pcm_current,0,0,totalshift); 311 312 313 seq++; 314 315 } 316 #endif 317 318 ve->curmark=j; 319 if(j>=testW)return(1); 320 return(0); 321 } 322 } 323 j+=ve->searchstep; 324 } 325 } 326 327 return(-1); 328 } 329 330 int _ve_envelope_mark(vorbis_dsp_state *v){ 331 envelope_lookup *ve=((private_state *)(v->backend_state))->ve; 332 vorbis_info *vi=v->vi; 333 codec_setup_info *ci=vi->codec_setup; 334 long centerW=v->centerW; 335 long beginW=centerW-ci->blocksizes[v->W]/4; 336 long endW=centerW+ci->blocksizes[v->W]/4; 337 if(v->W){ 338 beginW-=ci->blocksizes[v->lW]/4; 339 endW+=ci->blocksizes[v->nW]/4; 340 }else{ 341 beginW-=ci->blocksizes[0]/4; 342 endW+=ci->blocksizes[0]/4; 343 } 344 345 if(ve->curmark>=beginW && ve->curmark<endW)return(1); 346 { 347 long first=beginW/ve->searchstep; 348 long last=endW/ve->searchstep; 349 long i; 350 for(i=first;i<last;i++) 351 if(ve->mark[i])return(1); 352 } 353 return(0); 354 } 355 356 void _ve_envelope_shift(envelope_lookup *e,long shift){ 357 int smallsize=e->current/e->searchstep+VE_POST; /* adjust for placing marks 358 ahead of ve->current */ 359 int smallshift=shift/e->searchstep; 360 361 memmove(e->mark,e->mark+smallshift,(smallsize-smallshift)*sizeof(*e->mark)); 362 363 #if 0 364 for(i=0;i<VE_BANDS*e->ch;i++) 365 memmove(e->filter[i].markers, 366 e->filter[i].markers+smallshift, 367 (1024-smallshift)*sizeof(*(*e->filter).markers)); 368 totalshift+=shift; 369 #endif 370 371 e->current-=shift; 372 if(e->curmark>=0) 373 e->curmark-=shift; 374 e->cursor-=shift; 375 } 376
