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