/********************************************************************

 *                                                                  *

 * 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 https://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;

}