1 /********************************************************************
3 * THIS FILE IS PART OF THE Ogg Vorbis SOFTWARE CODEC SOURCE CODE. *
4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS SOURCE IS GOVERNED BY *
5 * THE GNU PUBLIC LICENSE 2, WHICH IS INCLUDED WITH THIS SOURCE. *
6 * PLEASE READ THESE TERMS DISTRIBUTING. *
8 * THE OggSQUISH SOURCE CODE IS (C) COPYRIGHT 1994-2000 *
9 * by Monty <monty@xiph.org> and The XIPHOPHORUS Company *
10 * http://www.xiph.org/ *
12 ********************************************************************
14 function: PCM data vector blocking, windowing and dis/reassembly
15 last mod: $Id: block.c,v 1.31 2000/06/14 10:13:35 xiphmont Exp $
17 Handle windowing, overlap-add, etc of the PCM vectors. This is made
18 more amusing by Vorbis' current two allowed block sizes.
20 Vorbis manipulates the dynamic range of the incoming PCM data
21 envelope to minimise time-domain energy leakage from percussive and
22 plosive waveforms being quantized in the MDCT domain.
24 ********************************************************************/
29 #include "vorbis/codec.h"
37 #include "sharedbook.h"
38 #include "bookinternal.h"
41 static int ilog2(unsigned int v){
50 /* pcm accumulator examples (not exhaustive):
52 <-------------- lW ---------------->
53 <--------------- W ---------------->
54 : .....|..... _______________ |
55 : .''' | '''_--- | |\ |
56 :.....''' |_____--- '''......| | \_______|
57 :.................|__________________|_______|__|______|
58 |<------ Sl ------>| > Sr < |endW
59 |beginSl |endSl | |endSr
60 |beginW |endlW |beginSr
64 <--------------- W ---------------->
65 | | .. ______________ |
67 |___.'___/`. | ---_____|
68 |_______|__|_______|_________________|
69 | >|Sl|< |<------ Sr ----->|endW
70 | | |endSl |beginSr |endSr
72 mult[0] |beginSl mult[n]
74 <-------------- lW ----------------->
76 : .............. ___ | |
78 :.....''' |/`....\|...|
79 :.........................|___|___|___|
88 /* block abstraction setup *********************************************/
94 int vorbis_block_init(vorbis_dsp_state *v, vorbis_block *vb){
95 memset(vb,0,sizeof(vorbis_block));
100 _oggpack_writeinit(&vb->opb);
105 void *_vorbis_block_alloc(vorbis_block *vb,long bytes){
106 bytes=(bytes+(WORD_ALIGN-1)) & ~(WORD_ALIGN-1);
107 if(bytes+vb->localtop>vb->localalloc){
108 /* can't just realloc... there are outstanding pointers */
110 struct alloc_chain *link=malloc(sizeof(struct alloc_chain));
111 vb->totaluse+=vb->localtop;
113 link->ptr=vb->localstore;
116 /* highly conservative */
117 vb->localalloc=bytes;
118 vb->localstore=malloc(vb->localalloc);
122 void *ret=(void *)(((char *)vb->localstore)+vb->localtop);
128 /* reap the chain, pull the ripcord */
129 void _vorbis_block_ripcord(vorbis_block *vb){
131 struct alloc_chain *reap=vb->reap;
133 struct alloc_chain *next=reap->next;
135 memset(reap,0,sizeof(struct alloc_chain));
139 /* consolidate storage */
141 vb->localstore=realloc(vb->localstore,vb->totaluse+vb->localalloc);
142 vb->localalloc+=vb->totaluse;
146 /* pull the ripcord */
151 int vorbis_block_clear(vorbis_block *vb){
153 if(vb->vd->analysisp)
154 _oggpack_writeclear(&vb->opb);
155 _vorbis_block_ripcord(vb);
156 if(vb->localstore)free(vb->localstore);
158 memset(vb,0,sizeof(vorbis_block));
162 /* Analysis side code, but directly related to blocking. Thus it's
163 here and not in analysis.c (which is for analysis transforms only).
164 The init is here because some of it is shared */
166 static int _vds_shared_init(vorbis_dsp_state *v,vorbis_info *vi,int encp){
168 memset(v,0,sizeof(vorbis_dsp_state));
171 v->modebits=ilog2(vi->modes);
173 v->transform[0]=calloc(VI_TRANSFORMB,sizeof(vorbis_look_transform *));
174 v->transform[1]=calloc(VI_TRANSFORMB,sizeof(vorbis_look_transform *));
176 /* MDCT is tranform 0 */
178 v->transform[0][0]=calloc(1,sizeof(mdct_lookup));
179 v->transform[1][0]=calloc(1,sizeof(mdct_lookup));
180 mdct_init(v->transform[0][0],vi->blocksizes[0]);
181 mdct_init(v->transform[1][0],vi->blocksizes[1]);
183 v->window[0][0][0]=calloc(VI_WINDOWB,sizeof(double *));
184 v->window[0][0][1]=v->window[0][0][0];
185 v->window[0][1][0]=v->window[0][0][0];
186 v->window[0][1][1]=v->window[0][0][0];
187 v->window[1][0][0]=calloc(VI_WINDOWB,sizeof(double *));
188 v->window[1][0][1]=calloc(VI_WINDOWB,sizeof(double *));
189 v->window[1][1][0]=calloc(VI_WINDOWB,sizeof(double *));
190 v->window[1][1][1]=calloc(VI_WINDOWB,sizeof(double *));
192 for(i=0;i<VI_WINDOWB;i++){
193 v->window[0][0][0][i]=
194 _vorbis_window(i,vi->blocksizes[0],vi->blocksizes[0]/2,vi->blocksizes[0]/2);
195 v->window[1][0][0][i]=
196 _vorbis_window(i,vi->blocksizes[1],vi->blocksizes[0]/2,vi->blocksizes[0]/2);
197 v->window[1][0][1][i]=
198 _vorbis_window(i,vi->blocksizes[1],vi->blocksizes[0]/2,vi->blocksizes[1]/2);
199 v->window[1][1][0][i]=
200 _vorbis_window(i,vi->blocksizes[1],vi->blocksizes[1]/2,vi->blocksizes[0]/2);
201 v->window[1][1][1][i]=
202 _vorbis_window(i,vi->blocksizes[1],vi->blocksizes[1]/2,vi->blocksizes[1]/2);
205 if(encp){ /* encode/decode differ here */
206 /* finish the codebooks */
207 v->fullbooks=calloc(vi->books,sizeof(codebook));
208 for(i=0;i<vi->books;i++)
209 vorbis_book_init_encode(v->fullbooks+i,vi->book_param[i]);
212 /* finish the codebooks */
213 v->fullbooks=calloc(vi->books,sizeof(codebook));
214 for(i=0;i<vi->books;i++)
215 vorbis_book_init_decode(v->fullbooks+i,vi->book_param[i]);
218 /* initialize the storage vectors to a decent size greater than the
221 v->pcm_storage=8192; /* we'll assume later that we have
222 a minimum of twice the blocksize of
223 accumulated samples in analysis */
224 v->pcm=malloc(vi->channels*sizeof(double *));
225 v->pcmret=malloc(vi->channels*sizeof(double *));
228 for(i=0;i<vi->channels;i++)
229 v->pcm[i]=calloc(v->pcm_storage,sizeof(double));
232 /* all 1 (large block) or 0 (small block) */
233 /* explicitly set for the sake of clarity */
234 v->lW=0; /* previous window size */
235 v->W=0; /* current window size */
237 /* all vector indexes; multiples of samples_per_envelope_step */
238 v->centerW=vi->blocksizes[1]/2;
240 v->pcm_current=v->centerW;
242 /* initialize all the mapping/backend lookups */
243 v->mode=calloc(vi->modes,sizeof(vorbis_look_mapping *));
244 for(i=0;i<vi->modes;i++){
245 int mapnum=vi->mode_param[i]->mapping;
246 int maptype=vi->map_type[mapnum];
247 v->mode[i]=_mapping_P[maptype]->look(v,vi->mode_param[i],
248 vi->map_param[mapnum]);
254 /* arbitrary settings and spec-mandated numbers get filled in here */
255 int vorbis_analysis_init(vorbis_dsp_state *v,vorbis_info *vi){
256 _vds_shared_init(v,vi,1);
258 /* Initialize the envelope multiplier storage */
260 v->envelope_storage=v->pcm_storage/vi->envelopesa;
261 v->multipliers=calloc(v->envelope_storage,sizeof(double));
262 _ve_envelope_init(&v->ve,vi->envelopesa);
264 v->envelope_current=v->centerW/vi->envelopesa;
268 void vorbis_dsp_clear(vorbis_dsp_state *v){
271 vorbis_info *vi=v->vi;
273 if(v->window[0][0][0]){
274 for(i=0;i<VI_WINDOWB;i++)
275 if(v->window[0][0][0][i])free(v->window[0][0][0][i]);
276 free(v->window[0][0][0]);
280 for(i=0;i<VI_WINDOWB;i++)
281 if(v->window[1][j][k][i])free(v->window[1][j][k][i]);
282 free(v->window[1][j][k]);
287 for(i=0;i<vi->channels;i++)
288 if(v->pcm[i])free(v->pcm[i]);
290 if(v->pcmret)free(v->pcmret);
292 if(v->multipliers)free(v->multipliers);
294 _ve_envelope_clear(&v->ve);
296 mdct_clear(v->transform[0][0]);
297 free(v->transform[0][0]);
298 free(v->transform[0]);
301 mdct_clear(v->transform[1][0]);
302 free(v->transform[1][0]);
303 free(v->transform[1]);
306 /* free mode lookups; these are actually vorbis_look_mapping structs */
308 for(i=0;i<vi->modes;i++){
309 int mapnum=vi->mode_param[i]->mapping;
310 int maptype=vi->map_type[mapnum];
311 _mapping_P[maptype]->free_look(v->mode[i]);
314 for(i=0;i<vi->books;i++)
315 vorbis_book_clear(v->fullbooks+i);
318 if(v->mode)free(v->mode);
319 if(v->fullbooks)free(v->fullbooks);
321 /* free header, header1, header2 */
322 if(v->header)free(v->header);
323 if(v->header1)free(v->header1);
324 if(v->header2)free(v->header2);
326 memset(v,0,sizeof(vorbis_dsp_state));
330 double **vorbis_analysis_buffer(vorbis_dsp_state *v, int vals){
332 vorbis_info *vi=v->vi;
334 /* free header, header1, header2 */
335 if(v->header)free(v->header);v->header=NULL;
336 if(v->header1)free(v->header1);v->header1=NULL;
337 if(v->header2)free(v->header2);v->header2=NULL;
339 /* Do we have enough storage space for the requested buffer? If not,
340 expand the PCM (and envelope) storage */
342 if(v->pcm_current+vals>=v->pcm_storage){
343 v->pcm_storage=v->pcm_current+vals*2;
344 v->envelope_storage=v->pcm_storage/v->vi->envelopesa;
346 for(i=0;i<vi->channels;i++){
347 v->pcm[i]=realloc(v->pcm[i],v->pcm_storage*sizeof(double));
349 v->multipliers=realloc(v->multipliers,v->envelope_storage*sizeof(double));
352 for(i=0;i<vi->channels;i++)
353 v->pcmret[i]=v->pcm[i]+v->pcm_current;
358 /* call with val<=0 to set eof */
360 int vorbis_analysis_wrote(vorbis_dsp_state *v, int vals){
361 vorbis_info *vi=v->vi;
363 /* We're encoding the end of the stream. Just make sure we have
364 [at least] a full block of zeroes at the end. */
367 vorbis_analysis_buffer(v,v->vi->blocksizes[1]*2);
368 v->eofflag=v->pcm_current;
369 v->pcm_current+=v->vi->blocksizes[1]*2;
370 for(i=0;i<vi->channels;i++)
371 memset(v->pcm[i]+v->eofflag,0,
372 (v->pcm_current-v->eofflag)*sizeof(double));
375 if(v->pcm_current+vals>v->pcm_storage)
378 v->pcm_current+=vals;
383 /* do the deltas, envelope shaping, pre-echo and determine the size of
384 the next block on which to continue analysis */
385 int vorbis_analysis_blockout(vorbis_dsp_state *v,vorbis_block *vb){
387 vorbis_info *vi=v->vi;
388 long beginW=v->centerW-vi->blocksizes[v->W]/2,centerNext;
390 /* check to see if we're done... */
391 if(v->eofflag==-1)return(0);
393 /* if we have any unfilled envelope blocks for which we have PCM
394 data, fill them up in before proceeding. */
396 if(v->pcm_current/vi->envelopesa>v->envelope_current){
397 /* This generates the multipliers, but does not sparsify the vector.
398 That's done by block before coding */
399 _ve_envelope_deltas(v);
402 /* By our invariant, we have lW, W and centerW set. Search for
403 the next boundary so we can determine nW (the next window size)
404 which lets us compute the shape of the current block's window */
406 if(vi->blocksizes[0]<vi->blocksizes[1]){
409 /* this is a long window; we start the search forward of centerW
410 because that's the fastest we could react anyway */
411 i=v->centerW+vi->blocksizes[1]/4-vi->blocksizes[0]/4;
413 /* short window. Search from centerW */
417 for(;i<v->envelope_current-1;i++){
418 /* Compare last with current; do we have an abrupt energy change? */
420 if(v->multipliers[i-1]*vi->preecho_thresh<
421 v->multipliers[i])break;
423 /* because the overlapping nature of the delta finding
424 'smears' the energy cliffs, also compare completely
425 unoverlapped areas just in case the plosive happened in an
428 if(v->multipliers[i-1]*vi->preecho_thresh<
429 v->multipliers[i+1])break;
433 if(i<v->envelope_current-1){
434 /* Ooo, we hit a multiplier. Is it beyond the boundary to make the
435 upcoming block large ? */
438 /* min boundary; nW large, next small */
439 largebound=v->centerW+vi->blocksizes[1]*3/4+vi->blocksizes[0]/4;
441 /* min boundary; nW large, next small */
442 largebound=v->centerW+vi->blocksizes[0]/2+vi->blocksizes[1]/2;
443 largebound/=vi->envelopesa;
451 /* Assume maximum; if the block is incomplete given current
452 buffered data, this will be detected below */
458 /* Do we actually have enough data *now* for the next block? The
459 reason to check is that if we had no multipliers, that could
460 simply been due to running out of data. In that case, we don't
461 know the size of the next block for sure and we need that now to
462 figure out the window shape of this block */
464 centerNext=v->centerW+vi->blocksizes[v->W]/4+vi->blocksizes[v->nW]/4;
467 /* center of next block + next block maximum right side. Note
468 that the next block needs an additional vi->envelopesa samples
469 to actually be written (for the last multiplier), but we didn't
470 need that to determine its size */
472 long blockbound=centerNext+vi->blocksizes[v->nW]/2;
473 if(v->pcm_current<blockbound)return(0); /* not enough data yet */
476 /* fill in the block. Note that for a short window, lW and nW are *short*
477 regardless of actual settings in the stream */
479 _vorbis_block_ripcord(vb);
490 vb->sequence=v->sequence;
491 vb->frameno=v->frameno;
492 vb->pcmend=vi->blocksizes[v->W];
494 /* copy the vectors; this uses the local storage in vb */
496 vb->pcm=_vorbis_block_alloc(vb,sizeof(double *)*vi->channels);
497 for(i=0;i<vi->channels;i++){
498 vb->pcm[i]=_vorbis_block_alloc(vb,vb->pcmend*sizeof(double));
499 memcpy(vb->pcm[i],v->pcm[i]+beginW,vi->blocksizes[v->W]*sizeof(double));
503 /* handle eof detection: eof==0 means that we've not yet received EOF
504 eof>0 marks the last 'real' sample in pcm[]
505 eof<0 'no more to do'; doesn't get here */
508 if(v->centerW>=v->eofflag){
515 /* advance storage vectors and clean up */
517 int new_centerNext=vi->blocksizes[1]/2;
518 int movementW=centerNext-new_centerNext;
519 int movementM=movementW/vi->envelopesa;
523 /* the multipliers and pcm stay synced up because the blocksize
524 must be multiples of samples_per_envelope_step (minimum
527 v->pcm_current-=movementW;
528 v->envelope_current-=movementM;
530 for(i=0;i<vi->channels;i++)
531 memmove(v->pcm[i],v->pcm[i]+movementW,
532 v->pcm_current*sizeof(double));
534 memmove(v->multipliers,v->multipliers+movementM,
535 v->envelope_current*sizeof(double));
539 v->centerW=new_centerNext;
544 v->eofflag-=movementW;
545 /* do not add padding to end of stream! */
546 if(v->centerW>=v->eofflag){
547 v->frameno+=v->eofflag;
549 v->frameno+=movementW;
552 v->frameno+=movementW;
559 int vorbis_synthesis_init(vorbis_dsp_state *v,vorbis_info *vi){
560 _vds_shared_init(v,vi,0);
562 /* Adjust centerW to allow an easier mechanism for determining output */
563 v->pcm_returned=v->centerW;
564 v->centerW-= vi->blocksizes[v->W]/4+vi->blocksizes[v->lW]/4;
571 /* Unike in analysis, the window is only partially applied for each
572 block. The time domain envelope is not yet handled at the point of
573 calling (as it relies on the previous block). */
575 int vorbis_synthesis_blockin(vorbis_dsp_state *v,vorbis_block *vb){
576 vorbis_info *vi=v->vi;
578 /* Shift out any PCM/multipliers that we returned previously */
579 /* centerW is currently the center of the last block added */
580 if(v->pcm_returned && v->centerW>vi->blocksizes[1]/2){
582 /* don't shift too much; we need to have a minimum PCM buffer of
585 int shiftPCM=v->centerW-vi->blocksizes[1]/2;
586 shiftPCM=(v->pcm_returned<shiftPCM?v->pcm_returned:shiftPCM);
588 v->pcm_current-=shiftPCM;
589 v->centerW-=shiftPCM;
590 v->pcm_returned-=shiftPCM;
594 for(i=0;i<vi->channels;i++)
595 memmove(v->pcm[i],v->pcm[i]+shiftPCM,
596 v->pcm_current*sizeof(double));
604 v->glue_bits+=vb->glue_bits;
605 v->time_bits+=vb->time_bits;
606 v->floor_bits+=vb->floor_bits;
607 v->res_bits+=vb->res_bits;
609 if(v->sequence+1 != vb->sequence)v->frameno=-1; /* out of sequence;
612 v->sequence=vb->sequence;
615 int sizeW=vi->blocksizes[v->W];
616 int centerW=v->centerW+vi->blocksizes[v->lW]/4+sizeW/4;
617 int beginW=centerW-sizeW/2;
618 int endW=beginW+sizeW;
623 /* Do we have enough PCM/mult storage for the block? */
624 if(endW>v->pcm_storage){
625 /* expand the storage */
626 v->pcm_storage=endW+vi->blocksizes[1];
628 for(i=0;i<vi->channels;i++)
629 v->pcm[i]=realloc(v->pcm[i],v->pcm_storage*sizeof(double));
632 /* overlap/add PCM */
637 endSl=vi->blocksizes[0]/2;
640 beginSl=vi->blocksizes[1]/4-vi->blocksizes[v->lW]/4;
641 endSl=beginSl+vi->blocksizes[v->lW]/2;
645 for(j=0;j<vi->channels;j++){
646 double *pcm=v->pcm[j]+beginW;
648 /* the overlap/add section */
649 for(i=beginSl;i<endSl;i++)
650 pcm[i]+=vb->pcm[j][i];
651 /* the remaining section */
653 pcm[i]=vb->pcm[j][i];
656 /* track the frame number... This is for convenience, but also
657 making sure our last packet doesn't end with added padding. If
658 the last packet is partial, the number of samples we'll have to
659 return will be past the vb->frameno.
661 This is not foolproof! It will be confused if we begin
662 decoding at the last page after a seek or hole. In that case,
663 we don't have a starting point to judge where the last frame
664 is. For this reason, vorbisfile will always try to make sure
665 it reads the last two marked pages in proper sequence */
668 v->frameno=vb->frameno;
670 v->frameno+=(centerW-v->centerW);
671 if(vb->frameno!=-1 && v->frameno!=vb->frameno){
672 if(v->frameno>vb->frameno && vb->eofflag){
673 /* partial last frame. Strip the padding off */
674 centerW-=(v->frameno-vb->frameno);
675 }/* else{ Shouldn't happen *unless* the bitstream is out of
676 spec. Either way, believe the bitstream } */
677 v->frameno=vb->frameno;
681 /* Update, cleanup */
686 if(vb->eofflag)v->eofflag=1;
692 int vorbis_synthesis_pcmout(vorbis_dsp_state *v,double ***pcm){
693 vorbis_info *vi=v->vi;
694 if(v->pcm_returned<v->centerW){
696 for(i=0;i<vi->channels;i++)
697 v->pcmret[i]=v->pcm[i]+v->pcm_returned;
699 return(v->centerW-v->pcm_returned);
704 int vorbis_synthesis_read(vorbis_dsp_state *v,int bytes){
705 if(bytes && v->pcm_returned+bytes>v->centerW)return(-1);
706 v->pcm_returned+=bytes;