diff options
Diffstat (limited to 'vorbis/lib/envelope.c')
| -rw-r--r-- | vorbis/lib/envelope.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/vorbis/lib/envelope.c b/vorbis/lib/envelope.c new file mode 100644 index 0000000..da75237 --- /dev/null +++ b/vorbis/lib/envelope.c @@ -0,0 +1,374 @@ +/******************************************************************** + * * + * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. * + * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS * + * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE * + * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. * + * * + * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 * + * by the Xiph.Org Foundation http://www.xiph.org/ * + * * + ******************************************************************** + + function: PCM data envelope analysis + + ********************************************************************/ + +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <math.h> +#include <ogg/ogg.h> +#include "vorbis/codec.h" +#include "codec_internal.h" + +#include "os.h" +#include "scales.h" +#include "envelope.h" +#include "mdct.h" +#include "misc.h" + +void _ve_envelope_init(envelope_lookup *e,vorbis_info *vi){ + codec_setup_info *ci=vi->codec_setup; + vorbis_info_psy_global *gi=&ci->psy_g_param; + int ch=vi->channels; + int i,j; + int n=e->winlength=128; + e->searchstep=64; /* not random */ + + e->minenergy=gi->preecho_minenergy; + e->ch=ch; + e->storage=128; + e->cursor=ci->blocksizes[1]/2; + e->mdct_win=_ogg_calloc(n,sizeof(*e->mdct_win)); + mdct_init(&e->mdct,n); + + for(i=0;i<n;i++){ + e->mdct_win[i]=sin(i/(n-1.)*M_PI); + e->mdct_win[i]*=e->mdct_win[i]; + } + + /* magic follows */ + e->band[0].begin=2; e->band[0].end=4; + e->band[1].begin=4; e->band[1].end=5; + e->band[2].begin=6; e->band[2].end=6; + e->band[3].begin=9; e->band[3].end=8; + e->band[4].begin=13; e->band[4].end=8; + e->band[5].begin=17; e->band[5].end=8; + e->band[6].begin=22; e->band[6].end=8; + + for(j=0;j<VE_BANDS;j++){ + n=e->band[j].end; + e->band[j].window=_ogg_malloc(n*sizeof(*e->band[0].window)); + for(i=0;i<n;i++){ + e->band[j].window[i]=sin((i+.5)/n*M_PI); + e->band[j].total+=e->band[j].window[i]; + } + e->band[j].total=1./e->band[j].total; + } + + e->filter=_ogg_calloc(VE_BANDS*ch,sizeof(*e->filter)); + e->mark=_ogg_calloc(e->storage,sizeof(*e->mark)); + +} + +void _ve_envelope_clear(envelope_lookup *e){ + int i; + mdct_clear(&e->mdct); + for(i=0;i<VE_BANDS;i++) + _ogg_free(e->band[i].window); + _ogg_free(e->mdct_win); + _ogg_free(e->filter); + _ogg_free(e->mark); + memset(e,0,sizeof(*e)); +} + +/* fairly straight threshhold-by-band based until we find something + that works better and isn't patented. */ + +static int _ve_amp(envelope_lookup *ve, + vorbis_info_psy_global *gi, + float *data, + envelope_band *bands, + envelope_filter_state *filters){ + long n=ve->winlength; + int ret=0; + long i,j; + float decay; + + /* we want to have a 'minimum bar' for energy, else we're just + basing blocks on quantization noise that outweighs the signal + itself (for low power signals) */ + + float minV=ve->minenergy; + float *vec=alloca(n*sizeof(*vec)); + + /* stretch is used to gradually lengthen the number of windows + considered prevoius-to-potential-trigger */ + int stretch=max(VE_MINSTRETCH,ve->stretch/2); + float penalty=gi->stretch_penalty-(ve->stretch/2-VE_MINSTRETCH); + if(penalty<0.f)penalty=0.f; + if(penalty>gi->stretch_penalty)penalty=gi->stretch_penalty; + + /*_analysis_output_always("lpcm",seq2,data,n,0,0, + totalshift+pos*ve->searchstep);*/ + + /* window and transform */ + for(i=0;i<n;i++) + vec[i]=data[i]*ve->mdct_win[i]; + mdct_forward(&ve->mdct,vec,vec); + + /*_analysis_output_always("mdct",seq2,vec,n/2,0,1,0); */ + + /* near-DC spreading function; this has nothing to do with + psychoacoustics, just sidelobe leakage and window size */ + { + float temp=vec[0]*vec[0]+.7*vec[1]*vec[1]+.2*vec[2]*vec[2]; + int ptr=filters->nearptr; + + /* the accumulation is regularly refreshed from scratch to avoid + floating point creep */ + if(ptr==0){ + decay=filters->nearDC_acc=filters->nearDC_partialacc+temp; + filters->nearDC_partialacc=temp; + }else{ + decay=filters->nearDC_acc+=temp; + filters->nearDC_partialacc+=temp; + } + filters->nearDC_acc-=filters->nearDC[ptr]; + filters->nearDC[ptr]=temp; + + decay*=(1./(VE_NEARDC+1)); + filters->nearptr++; + if(filters->nearptr>=VE_NEARDC)filters->nearptr=0; + decay=todB(&decay)*.5-15.f; + } + + /* perform spreading and limiting, also smooth the spectrum. yes, + the MDCT results in all real coefficients, but it still *behaves* + like real/imaginary pairs */ + for(i=0;i<n/2;i+=2){ + float val=vec[i]*vec[i]+vec[i+1]*vec[i+1]; + val=todB(&val)*.5f; + if(val<decay)val=decay; + if(val<minV)val=minV; + vec[i>>1]=val; + decay-=8.; + } + + /*_analysis_output_always("spread",seq2++,vec,n/4,0,0,0);*/ + + /* perform preecho/postecho triggering by band */ + for(j=0;j<VE_BANDS;j++){ + float acc=0.; + float valmax,valmin; + + /* accumulate amplitude */ + for(i=0;i<bands[j].end;i++) + acc+=vec[i+bands[j].begin]*bands[j].window[i]; + + acc*=bands[j].total; + + /* convert amplitude to delta */ + { + int p,this=filters[j].ampptr; + float postmax,postmin,premax=-99999.f,premin=99999.f; + + p=this; + p--; + if(p<0)p+=VE_AMP; + postmax=max(acc,filters[j].ampbuf[p]); + postmin=min(acc,filters[j].ampbuf[p]); + + for(i=0;i<stretch;i++){ + p--; + if(p<0)p+=VE_AMP; + premax=max(premax,filters[j].ampbuf[p]); + premin=min(premin,filters[j].ampbuf[p]); + } + + valmin=postmin-premin; + valmax=postmax-premax; + + /*filters[j].markers[pos]=valmax;*/ + filters[j].ampbuf[this]=acc; + filters[j].ampptr++; + if(filters[j].ampptr>=VE_AMP)filters[j].ampptr=0; + } + + /* look at min/max, decide trigger */ + if(valmax>gi->preecho_thresh[j]+penalty){ + ret|=1; + ret|=4; + } + if(valmin<gi->postecho_thresh[j]-penalty)ret|=2; + } + + return(ret); +} + +#if 0 +static int seq=0; +static ogg_int64_t totalshift=-1024; +#endif + +long _ve_envelope_search(vorbis_dsp_state *v){ + vorbis_info *vi=v->vi; + codec_setup_info *ci=vi->codec_setup; + vorbis_info_psy_global *gi=&ci->psy_g_param; + envelope_lookup *ve=((private_state *)(v->backend_state))->ve; + long i,j; + + int first=ve->current/ve->searchstep; + int last=v->pcm_current/ve->searchstep-VE_WIN; + if(first<0)first=0; + + /* make sure we have enough storage to match the PCM */ + if(last+VE_WIN+VE_POST>ve->storage){ + ve->storage=last+VE_WIN+VE_POST; /* be sure */ + ve->mark=_ogg_realloc(ve->mark,ve->storage*sizeof(*ve->mark)); + } + + for(j=first;j<last;j++){ + int ret=0; + + ve->stretch++; + if(ve->stretch>VE_MAXSTRETCH*2) + ve->stretch=VE_MAXSTRETCH*2; + + for(i=0;i<ve->ch;i++){ + float *pcm=v->pcm[i]+ve->searchstep*(j); + ret|=_ve_amp(ve,gi,pcm,ve->band,ve->filter+i*VE_BANDS); + } + + ve->mark[j+VE_POST]=0; + if(ret&1){ + ve->mark[j]=1; + ve->mark[j+1]=1; + } + + if(ret&2){ + ve->mark[j]=1; + if(j>0)ve->mark[j-1]=1; + } + + if(ret&4)ve->stretch=-1; + } + + ve->current=last*ve->searchstep; + + { + long centerW=v->centerW; + long testW= + centerW+ + ci->blocksizes[v->W]/4+ + ci->blocksizes[1]/2+ + ci->blocksizes[0]/4; + + j=ve->cursor; + + while(j<ve->current-(ve->searchstep)){/* account for postecho + working back one window */ + if(j>=testW)return(1); + + ve->cursor=j; + + if(ve->mark[j/ve->searchstep]){ + if(j>centerW){ + +#if 0 + if(j>ve->curmark){ + float *marker=alloca(v->pcm_current*sizeof(*marker)); + int l,m; + memset(marker,0,sizeof(*marker)*v->pcm_current); + fprintf(stderr,"mark! seq=%d, cursor:%fs time:%fs\n", + seq, + (totalshift+ve->cursor)/44100., + (totalshift+j)/44100.); + _analysis_output_always("pcmL",seq,v->pcm[0],v->pcm_current,0,0,totalshift); + _analysis_output_always("pcmR",seq,v->pcm[1],v->pcm_current,0,0,totalshift); + + _analysis_output_always("markL",seq,v->pcm[0],j,0,0,totalshift); + _analysis_output_always("markR",seq,v->pcm[1],j,0,0,totalshift); + + for(m=0;m<VE_BANDS;m++){ + char buf[80]; + sprintf(buf,"delL%d",m); + for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->filter[m].markers[l]*.1; + _analysis_output_always(buf,seq,marker,v->pcm_current,0,0,totalshift); + } + + for(m=0;m<VE_BANDS;m++){ + char buf[80]; + sprintf(buf,"delR%d",m); + for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->filter[m+VE_BANDS].markers[l]*.1; + _analysis_output_always(buf,seq,marker,v->pcm_current,0,0,totalshift); + } + + for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->mark[l]*.4; + _analysis_output_always("mark",seq,marker,v->pcm_current,0,0,totalshift); + + + seq++; + + } +#endif + + ve->curmark=j; + if(j>=testW)return(1); + return(0); + } + } + j+=ve->searchstep; + } + } + + return(-1); +} + +int _ve_envelope_mark(vorbis_dsp_state *v){ + envelope_lookup *ve=((private_state *)(v->backend_state))->ve; + vorbis_info *vi=v->vi; + codec_setup_info *ci=vi->codec_setup; + long centerW=v->centerW; + long beginW=centerW-ci->blocksizes[v->W]/4; + long endW=centerW+ci->blocksizes[v->W]/4; + if(v->W){ + beginW-=ci->blocksizes[v->lW]/4; + endW+=ci->blocksizes[v->nW]/4; + }else{ + beginW-=ci->blocksizes[0]/4; + endW+=ci->blocksizes[0]/4; + } + + if(ve->curmark>=beginW && ve->curmark<endW)return(1); + { + long first=beginW/ve->searchstep; + long last=endW/ve->searchstep; + long i; + for(i=first;i<last;i++) + if(ve->mark[i])return(1); + } + return(0); +} + +void _ve_envelope_shift(envelope_lookup *e,long shift){ + int smallsize=e->current/e->searchstep+VE_POST; /* adjust for placing marks + ahead of ve->current */ + int smallshift=shift/e->searchstep; + + memmove(e->mark,e->mark+smallshift,(smallsize-smallshift)*sizeof(*e->mark)); + +#if 0 + for(i=0;i<VE_BANDS*e->ch;i++) + memmove(e->filter[i].markers, + e->filter[i].markers+smallshift, + (1024-smallshift)*sizeof(*(*e->filter).markers)); + totalshift+=shift; +#endif + + e->current-=shift; + if(e->curmark>=0) + e->curmark-=shift; + e->cursor-=shift; +} |