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/********************************************************************
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 *                                                                  *
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 * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *
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 *                                                                  *
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 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
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 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
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 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
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 *                                                                  *
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 * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003    *
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 * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
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 *                                                                  *
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 ********************************************************************
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 function: single-block PCM synthesis
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 last mod: $Id: synthesis.c,v 1.1 2003/06/24 00:46:01 ace Exp $
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 ********************************************************************/
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#include <stdio.h>
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#include "ogg.h"
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#include "ivorbiscodec.h"
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#include "codec_internal.h"
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#include "registry.h"
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#include "misc.h"
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#include "os.h"
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extern void *_vorbis_block_alloc(vorbis_block *vb,long bytes);
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int vorbis_synthesis(vorbis_block *vb,ogg_packet *op,int decodep){
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  vorbis_dsp_state     *vd=vb->vd;
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  private_state        *b=(private_state *)vd->backend_state;
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  vorbis_info          *vi=vd->vi;
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  codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;
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  oggpack_buffer       *opb=&vb->opb;
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  int                   type,mode,i;
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  /* first things first.  Make sure decode is ready */
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  extern void _vorbis_block_ripcord(vorbis_block *vb);
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  _vorbis_block_ripcord(vb);
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  oggpack_readinit(opb,op->packet);
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  /* Check the packet type */
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  if(oggpack_read(opb,1)!=0){
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    /* Oops.  This is not an audio data packet */
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    return(OV_ENOTAUDIO);
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  }
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  /* read our mode and pre/post windowsize */
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  mode=oggpack_read(opb,b->modebits);
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  if(mode==-1)return(OV_EBADPACKET);
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  vb->mode=mode;
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  vb->W=ci->mode_param[mode]->blockflag;
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  if(vb->W){
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    vb->lW=oggpack_read(opb,1);
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    vb->nW=oggpack_read(opb,1);
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    if(vb->nW==-1)   return(OV_EBADPACKET);
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  }else{
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    vb->lW=0;
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    vb->nW=0;
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  }
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  /* more setup */
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  vb->granulepos=op->granulepos;
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  vb->sequence=op->packetno-3; /* first block is third packet */
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  vb->eofflag=op->e_o_s;
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  if(decodep){
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    /* alloc pcm passback storage */
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    vb->pcmend=ci->blocksizes[vb->W];
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    vb->pcm=(ogg_int32_t **)_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels);
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    for(i=0;i<vi->channels;i++)
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      vb->pcm[i]=(ogg_int32_t *)_vorbis_block_alloc(vb,vb->pcmend*sizeof(*vb->pcm[i]));
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    /* unpack_header enforces range checking */
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    type=ci->map_type[ci->mode_param[mode]->mapping];
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    return(_mapping_P[type]->inverse(vb,b->mode[mode]));
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  }else{
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    /* no pcm */
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    vb->pcmend=0;
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    vb->pcm=NULL;
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    return(0);
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  }
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}
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long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
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  codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;
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  oggpack_buffer       opb;
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  int                  mode;
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  oggpack_readinit(&opb,op->packet);
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  /* Check the packet type */
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  if(oggpack_read(&opb,1)!=0){
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    /* Oops.  This is not an audio data packet */
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    return(OV_ENOTAUDIO);
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  }
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  {
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    int modebits=0;
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    int v=ci->modes;
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    while(v>1){
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      modebits++;
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      v>>=1;
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    }
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    /* read our mode and pre/post windowsize */
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    mode=oggpack_read(&opb,modebits);
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  }
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  if(mode==-1)return(OV_EBADPACKET);
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  return(ci->blocksizes[ci->mode_param[mode]->blockflag]);
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}
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