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/********************************************************************
* *
* THIS FILE IS PART OF THE Ogg Vorbis SOFTWARE CODEC SOURCE CODE. *
* USE, DISTRIBUTION AND REPRODUCTION OF THIS SOURCE IS GOVERNED BY *
* THE GNU PUBLIC LICENSE 2, WHICH IS INCLUDED WITH THIS SOURCE. *
* PLEASE READ THESE TERMS DISTRIBUTING. *
* *
* THE OggSQUISH SOURCE CODE IS (C) COPYRIGHT 1994-2000 *
* by Monty <monty@xiph.org> and The XIPHOPHORUS Company *
* http://www.xiph.org/ *
* *
********************************************************************
function: single-block PCM synthesis
last mod: $Id: synthesis.c,v 1.17.4.1.2.2 2000/09/26 18:45:34 jack Exp $
********************************************************************/
#include <stdio.h>
#include <ogg/ogg.h>
#include "vorbis/codec.h"
#include "registry.h"
#include "misc.h"
#include "os.h"
int vorbis_synthesis(vorbis_block *vb,ogg_packet *op){
vorbis_dsp_state *vd=vb->vd;
vorbis_info *vi=vd->vi;
oggpack_buffer *opb=&vb->opb;
int type,mode,i;
/* first things first. Make sure decode is ready */
_vorbis_block_ripcord(vb);
oggpack_readinit(opb,op->packet,op->bytes);
/* Check the packet type */
if(oggpack_read(opb,1)!=0){
/* Oops. This is not an audio data packet */
return(-1);
}
/* read our mode and pre/post windowsize */
mode=oggpack_read(opb,vd->modebits);
if(mode==-1)return(-1);
vb->mode=mode;
vb->W=vi->mode_param[mode]->blockflag;
if(vb->W){
vb->lW=oggpack_read(opb,1);
vb->nW=oggpack_read(opb,1);
if(vb->nW==-1) return(-1);
}else{
vb->lW=0;
vb->nW=0;
}
/* more setup */
vb->granulepos=op->granulepos;
vb->sequence=op->packetno-3; /* first block is third packet */
vb->eofflag=op->e_o_s;
/* alloc pcm passback storage */
vb->pcmend=vi->blocksizes[vb->W];
vb->pcm=_vorbis_block_alloc(vb,sizeof(float *)*vi->channels);
for(i=0;i<vi->channels;i++)
vb->pcm[i]=_vorbis_block_alloc(vb,vb->pcmend*sizeof(float));
/* unpack_header enforces range checking */
type=vi->map_type[vi->mode_param[mode]->mapping];
return(_mapping_P[type]->inverse(vb,vd->mode[mode]));
}
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