vrshoot: e7ca128b8713 libs/vorbis/envelope.c

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view libs/vorbis/envelope.c @ 1:e7ca128b8713

looks nice :)

author	John Tsiombikas <nuclear@member.fsf.org>
date	Sun, 02 Feb 2014 00:35:22 +0200
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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 * *

9 * by the Xiph.Org Foundation http://www.xiph.org/ *

10 * *

11 ********************************************************************

13 function: PCM data envelope analysis

14 last mod: $Id: envelope.c 16227 2009-07-08 06:58:46Z xiphmont $

16 ********************************************************************/

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"

26 #include "os.h"

27 #include "scales.h"

28 #include "envelope.h"

29 #include "mdct.h"

30 #include "misc.h"

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 */

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);

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 }

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;

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 }

71 e->filter=_ogg_calloc(VE_BANDS*ch,sizeof(*e->filter));

72 e->mark=_ogg_calloc(e->storage,sizeof(*e->mark));

74 }

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 }

87 /* fairly straight threshhold-by-band based until we find something

88 that works better and isn't patented. */

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;

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 }