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envelope.c
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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 1994-2002 *
9  * by the XIPHOPHORUS Company http://www.xiph.org/ *
10  * *
11  ********************************************************************
12 
13  function: PCM data envelope analysis
14  last mod: $Id: envelope.c,v 1.54 2003/09/05 23:17:49 giles Exp $
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 
35  int ch=vi->channels;
36  int i,j;
37  int n=e->winlength=128;
38  e->searchstep=64; /* not random */
39 
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 
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,
92  float *data,
93  envelope_band *bands,
94  envelope_filter_state *filters,
95  long pos){
96  long n=ve->winlength;
97  int ret=0;
98  long i,j;
99  float decay;
100 
101  /* we want to have a 'minimum bar' for energy, else we're just
102  basing blocks on quantization noise that outweighs the signal
103  itself (for low power signals) */
104 
105  float minV=ve->minenergy;
106  float *vec=alloca(n*sizeof(*vec));
107 
108  /* stretch is used to gradually lengthen the number of windows
109  considered prevoius-to-potential-trigger */
110  int stretch=max(VE_MINSTRETCH,ve->stretch/2);
111  float penalty=gi->stretch_penalty-(ve->stretch/2-VE_MINSTRETCH);
112  if(penalty<0.f)penalty=0.f;
113  if(penalty>gi->stretch_penalty)penalty=gi->stretch_penalty;
114 
115  /*_analysis_output_always("lpcm",seq2,data,n,0,0,
116  totalshift+pos*ve->searchstep);*/
117 
118  /* window and transform */
119  for(i=0;i<n;i++)
120  vec[i]=data[i]*ve->mdct_win[i];
121  mdct_forward(&ve->mdct,vec,vec);
122 
123  /*_analysis_output_always("mdct",seq2,vec,n/2,0,1,0); */
124 
125  /* near-DC spreading function; this has nothing to do with
126  psychoacoustics, just sidelobe leakage and window size */
127  {
128  float temp=vec[0]*vec[0]+.7*vec[1]*vec[1]+.2*vec[2]*vec[2];
129  int ptr=filters->nearptr;
130 
131  /* the accumulation is regularly refreshed from scratch to avoid
132  floating point creep */
133  if(ptr==0){
134  decay=filters->nearDC_acc=filters->nearDC_partialacc+temp;
135  filters->nearDC_partialacc=temp;
136  }else{
137  decay=filters->nearDC_acc+=temp;
138  filters->nearDC_partialacc+=temp;
139  }
140  filters->nearDC_acc-=filters->nearDC[ptr];
141  filters->nearDC[ptr]=temp;
142 
143  decay*=(1./(VE_NEARDC+1));
144  filters->nearptr++;
145  if(filters->nearptr>=VE_NEARDC)filters->nearptr=0;
146  decay=todB(&decay)*.5-15.f;
147  }
148 
149  /* perform spreading and limiting, also smooth the spectrum. yes,
150  the MDCT results in all real coefficients, but it still *behaves*
151  like real/imaginary pairs */
152  for(i=0;i<n/2;i+=2){
153  float val=vec[i]*vec[i]+vec[i+1]*vec[i+1];
154  val=todB(&val)*.5f;
155  if(val<decay)val=decay;
156  if(val<minV)val=minV;
157  vec[i>>1]=val;
158  decay-=8.;
159  }
160 
161  /*_analysis_output_always("spread",seq2++,vec,n/4,0,0,0);*/
162 
163  /* perform preecho/postecho triggering by band */
164  for(j=0;j<VE_BANDS;j++){
165  float acc=0.;
166  float valmax,valmin;
167 
168  /* accumulate amplitude */
169  for(i=0;i<bands[j].end;i++)
170  acc+=vec[i+bands[j].begin]*bands[j].window[i];
171 
172  acc*=bands[j].total;
173 
174  /* convert amplitude to delta */
175  {
176  int p,this=filters[j].ampptr;
177  float postmax,postmin,premax=-99999.f,premin=99999.f;
178 
179  p=this;
180  p--;
181  if(p<0)p+=VE_AMP;
182  postmax=max(acc,filters[j].ampbuf[p]);
183  postmin=min(acc,filters[j].ampbuf[p]);
184 
185  for(i=0;i<stretch;i++){
186  p--;
187  if(p<0)p+=VE_AMP;
188  premax=max(premax,filters[j].ampbuf[p]);
189  premin=min(premin,filters[j].ampbuf[p]);
190  }
191 
192  valmin=postmin-premin;
193  valmax=postmax-premax;
194 
195  /*filters[j].markers[pos]=valmax;*/
196  filters[j].ampbuf[this]=acc;
197  filters[j].ampptr++;
198  if(filters[j].ampptr>=VE_AMP)filters[j].ampptr=0;
199  }
200 
201  /* look at min/max, decide trigger */
202  if(valmax>gi->preecho_thresh[j]+penalty){
203  ret|=1;
204  ret|=4;
205  }
206  if(valmin<gi->postecho_thresh[j]-penalty)ret|=2;
207  }
208 
209  return(ret);
210 }
211 
212 #if 0
213 static int seq=0;
214 static ogg_int64_t totalshift=-1024;
215 #endif
216 
218  vorbis_info *vi=v->vi;
221  envelope_lookup *ve=((private_state *)(v->backend_state))->ve;
222  long i,j;
223 
224  int first=ve->current/ve->searchstep;
225  int last=v->pcm_current/ve->searchstep-VE_WIN;
226  if(first<0)first=0;
227 
228  /* make sure we have enough storage to match the PCM */
229  if(last+VE_WIN+VE_POST>ve->storage){
230  ve->storage=last+VE_WIN+VE_POST; /* be sure */
231  ve->mark=_ogg_realloc(ve->mark,ve->storage*sizeof(*ve->mark));
232  }
233 
234  for(j=first;j<last;j++){
235  int ret=0;
236 
237  ve->stretch++;
238  if(ve->stretch>VE_MAXSTRETCH*2)
239  ve->stretch=VE_MAXSTRETCH*2;
240 
241  for(i=0;i<ve->ch;i++){
242  float *pcm=v->pcm[i]+ve->searchstep*(j);
243  ret|=_ve_amp(ve,gi,pcm,ve->band,ve->filter+i*VE_BANDS,j);
244  }
245 
246  ve->mark[j+VE_POST]=0;
247  if(ret&1){
248  ve->mark[j]=1;
249  ve->mark[j+1]=1;
250  }
251 
252  if(ret&2){
253  ve->mark[j]=1;
254  if(j>0)ve->mark[j-1]=1;
255  }
256 
257  if(ret&4)ve->stretch=-1;
258  }
259 
260  ve->current=last*ve->searchstep;
261 
262  {
263  long centerW=v->centerW;
264  long testW=
265  centerW+
266  ci->blocksizes[v->W]/4+
267  ci->blocksizes[1]/2+
268  ci->blocksizes[0]/4;
269 
270  j=ve->cursor;
271 
272  while(j<ve->current-(ve->searchstep)){/* account for postecho
273  working back one window */
274  if(j>=testW)return(1);
275 
276  ve->cursor=j;
277 
278  if(ve->mark[j/ve->searchstep]){
279  if(j>centerW){
280 
281  #if 0
282  if(j>ve->curmark){
283  float *marker=alloca(v->pcm_current*sizeof(*marker));
284  int l,m;
285  memset(marker,0,sizeof(*marker)*v->pcm_current);
286  fprintf(stderr,"mark! seq=%d, cursor:%fs time:%fs\n",
287  seq,
288  (totalshift+ve->cursor)/44100.,
289  (totalshift+j)/44100.);
290  _analysis_output_always("pcmL",seq,v->pcm[0],v->pcm_current,0,0,totalshift);
291  _analysis_output_always("pcmR",seq,v->pcm[1],v->pcm_current,0,0,totalshift);
292 
293  _analysis_output_always("markL",seq,v->pcm[0],j,0,0,totalshift);
294  _analysis_output_always("markR",seq,v->pcm[1],j,0,0,totalshift);
295 
296  for(m=0;m<VE_BANDS;m++){
297  char buf[80];
298  sprintf(buf,"delL%d",m);
299  for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->filter[m].markers[l]*.1;
300  _analysis_output_always(buf,seq,marker,v->pcm_current,0,0,totalshift);
301  }
302 
303  for(m=0;m<VE_BANDS;m++){
304  char buf[80];
305  sprintf(buf,"delR%d",m);
306  for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->filter[m+VE_BANDS].markers[l]*.1;
307  _analysis_output_always(buf,seq,marker,v->pcm_current,0,0,totalshift);
308  }
309 
310  for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->mark[l]*.4;
311  _analysis_output_always("mark",seq,marker,v->pcm_current,0,0,totalshift);
312 
313 
314  seq++;
315 
316  }
317 #endif
318 
319  ve->curmark=j;
320  if(j>=testW)return(1);
321  return(0);
322  }
323  }
324  j+=ve->searchstep;
325  }
326  }
327 
328  return(-1);
329 }
330 
332  envelope_lookup *ve=((private_state *)(v->backend_state))->ve;
333  vorbis_info *vi=v->vi;
335  long centerW=v->centerW;
336  long beginW=centerW-ci->blocksizes[v->W]/4;
337  long endW=centerW+ci->blocksizes[v->W]/4;
338  if(v->W){
339  beginW-=ci->blocksizes[v->lW]/4;
340  endW+=ci->blocksizes[v->nW]/4;
341  }else{
342  beginW-=ci->blocksizes[0]/4;
343  endW+=ci->blocksizes[0]/4;
344  }
345 
346  if(ve->curmark>=beginW && ve->curmark<endW)return(1);
347  {
348  long first=beginW/ve->searchstep;
349  long last=endW/ve->searchstep;
350  long i;
351  for(i=first;i<last;i++)
352  if(ve->mark[i])return(1);
353  }
354  return(0);
355 }
356 
358  int smallsize=e->current/e->searchstep+VE_POST; /* adjust for placing marks
359  ahead of ve->current */
360  int smallshift=shift/e->searchstep;
361 
362  memmove(e->mark,e->mark+smallshift,(smallsize-smallshift)*sizeof(*e->mark));
363 
364  #if 0
365  for(i=0;i<VE_BANDS*e->ch;i++)
366  memmove(e->filter[i].markers,
367  e->filter[i].markers+smallshift,
368  (1024-smallshift)*sizeof(*(*e->filter).markers));
369  totalshift+=shift;
370  #endif
371 
372  e->current-=shift;
373  if(e->curmark>=0)
374  e->curmark-=shift;
375  e->cursor-=shift;
376 }
377 
378 
379 
380 
381 
382 
float ** pcm
Definition: codec.h:63
#define min(a, b)
#define VE_NEARDC
Definition: envelope.h:29
int pcm_current
Definition: codec.h:66
#define VE_BANDS
Definition: envelope.h:28
const GLdouble * v
Definition: glext.h:2936
void _ve_envelope_shift(envelope_lookup *e, long shift)
Definition: envelope.c:357
GLenum GLsizei n
Definition: glext.h:3705
void mdct_init(mdct_lookup *lookup, int n)
Definition: mdct.c:52
void mdct_forward(mdct_lookup *init, DATA_TYPE *in, DATA_TYPE *out)
Definition: mdct.c:493
void _analysis_output_always(char *base, int i, float *v, int n, int bark, int dB, ogg_int64_t off)
Definition: analysis.c:67
#define _ogg_free
Definition: os_types.h:41
int _ve_envelope_mark(vorbis_dsp_state *v)
Definition: envelope.c:331
void _ve_envelope_clear(envelope_lookup *e)
Definition: envelope.c:76
void _ve_envelope_init(envelope_lookup *e, vorbis_info *vi)
Definition: envelope.c:32
int i
Definition: process.py:33
list l
Definition: prepare.py:17
vorbis_info * vi
Definition: codec.h:61
void * codec_setup
Definition: codec.h:53
int channels
Definition: codec.h:30
vorbis_info_psy_global psy_g_param
float total
Definition: envelope.h:49
envelope_filter_state * filter
Definition: envelope.h:62
#define VE_AMP
Definition: envelope.h:26
#define VE_MINSTRETCH
Definition: envelope.h:31
GLsizei GLsizei GLenum GLenum const GLvoid * data
Definition: glext.h:2853
long centerW
Definition: codec.h:75
mdct_lookup mdct
Definition: envelope.h:58
#define VE_MAXSTRETCH
Definition: envelope.h:32
float ampbuf[VE_AMP]
Definition: envelope.h:35
#define _ogg_realloc
Definition: os_types.h:40
#define M_PI
Definition: os.h:41
prefInfo window
float preecho_thresh[VE_BANDS]
Definition: psy.h:71
float * mdct_win
Definition: envelope.h:59
tuple f
Definition: idal.py:89
envelope_band band[VE_BANDS]
Definition: envelope.h:61
float minenergy
Definition: envelope.h:56
#define _ogg_calloc
Definition: os_types.h:39
#define VE_WIN
Definition: envelope.h:24
void mdct_clear(mdct_lookup *l)
Definition: mdct.c:339
long _ve_envelope_search(vorbis_dsp_state *v)
Definition: envelope.c:217
float * window
Definition: envelope.h:48
GLint j
Definition: qgl.h:264
GLint * first
Definition: glext.h:3036
float preecho_minenergy
Definition: psy.h:74
#define max(x, y)
Definition: os.h:70
int64_t ogg_int64_t
Definition: os_types.h:140
GLfloat GLfloat p
Definition: glext.h:4674
#define VE_POST
Definition: envelope.h:25
int sprintf(idStr &string, const char *fmt,...)
Definition: Str.cpp:1528
float nearDC[VE_NEARDC]
Definition: envelope.h:38
float stretch_penalty
Definition: psy.h:73
void * backend_state
Definition: codec.h:85
#define _ogg_malloc
Definition: os_types.h:38