michael@0: /********************************************************************
michael@0:  *                                                                  *
michael@0:  * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *
michael@0:  *                                                                  *
michael@0:  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
michael@0:  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
michael@0:  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
michael@0:  *                                                                  *
michael@0:  * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003    *
michael@0:  * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
michael@0:  *                                                                  *
michael@0:  ********************************************************************
michael@0: 
michael@0:  function: single-block PCM synthesis
michael@0:  last mod: $Id: synthesis.c,v 1.4 2003/03/29 03:07:21 xiphmont Exp $
michael@0: 
michael@0:  ********************************************************************/
michael@0: 
michael@0: #include <stdio.h>
michael@0: #include <ogg/ogg.h>
michael@0: #include "ivorbiscodec.h"
michael@0: #include "codec_internal.h"
michael@0: #include "registry.h"
michael@0: #include "misc.h"
michael@0: #include "block.h"
michael@0: 
michael@0: static int _vorbis_synthesis1(vorbis_block *vb,ogg_packet *op,int decodep){
michael@0:   vorbis_dsp_state     *vd= vb ? vb->vd : 0;
michael@0:   private_state        *b= vd ? (private_state *)vd->backend_state: 0;
michael@0:   vorbis_info          *vi= vd ? vd->vi : 0;
michael@0:   codec_setup_info     *ci= vi ? (codec_setup_info *)vi->codec_setup : 0;
michael@0:   oggpack_buffer       *opb=vb ? &vb->opb : 0;
michael@0:   int                   type,mode,i;
michael@0:  
michael@0:   if (!vd || !b || !vi || !ci || !opb) {
michael@0:     return OV_EBADPACKET;
michael@0:   }
michael@0: 
michael@0:   /* first things first.  Make sure decode is ready */
michael@0:   _vorbis_block_ripcord(vb);
michael@0:   oggpack_readinit(opb,op->packet,op->bytes);
michael@0: 
michael@0:   /* Check the packet type */
michael@0:   if(oggpack_read(opb,1)!=0){
michael@0:     /* Oops.  This is not an audio data packet */
michael@0:     return(OV_ENOTAUDIO);
michael@0:   }
michael@0: 
michael@0:   /* read our mode and pre/post windowsize */
michael@0:   mode=oggpack_read(opb,b->modebits);
michael@0:   if(mode==-1)return(OV_EBADPACKET);
michael@0:   
michael@0:   vb->mode=mode;
michael@0:   if(!ci->mode_param[mode]){
michael@0:     return(OV_EBADPACKET);
michael@0:   }
michael@0: 
michael@0:   vb->W=ci->mode_param[mode]->blockflag;
michael@0:   if(vb->W){
michael@0:     vb->lW=oggpack_read(opb,1);
michael@0:     vb->nW=oggpack_read(opb,1);
michael@0:     if(vb->nW==-1)   return(OV_EBADPACKET);
michael@0:   }else{
michael@0:     vb->lW=0;
michael@0:     vb->nW=0;
michael@0:   }
michael@0:   
michael@0:   /* more setup */
michael@0:   vb->granulepos=op->granulepos;
michael@0:   vb->sequence=op->packetno-3; /* first block is third packet */
michael@0:   vb->eofflag=op->e_o_s;
michael@0: 
michael@0:   if(decodep){
michael@0:     /* alloc pcm passback storage */
michael@0:     vb->pcmend=ci->blocksizes[vb->W];
michael@0:     vb->pcm=(ogg_int32_t **)_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels);
michael@0:     for(i=0;i<vi->channels;i++)
michael@0:       vb->pcm[i]=(ogg_int32_t *)_vorbis_block_alloc(vb,vb->pcmend*sizeof(*vb->pcm[i]));
michael@0:     
michael@0:     /* unpack_header enforces range checking */
michael@0:     type=ci->map_type[ci->mode_param[mode]->mapping];
michael@0:     
michael@0:     return(_mapping_P[type]->inverse(vb,b->mode[mode]));
michael@0:   }else{
michael@0:     /* no pcm */
michael@0:     vb->pcmend=0;
michael@0:     vb->pcm=NULL;
michael@0:     
michael@0:     return(0);
michael@0:   }
michael@0: }
michael@0: 
michael@0: int vorbis_synthesis(vorbis_block *vb,ogg_packet *op){
michael@0:   return _vorbis_synthesis1(vb,op,1);
michael@0: }
michael@0: 
michael@0: /* used to track pcm position without actually performing decode.
michael@0:    Useful for sequential 'fast forward' */
michael@0: int vorbis_synthesis_trackonly(vorbis_block *vb,ogg_packet *op){
michael@0:   return _vorbis_synthesis1(vb,op,0);
michael@0: }
michael@0: 
michael@0: long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
michael@0:   codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;
michael@0:   oggpack_buffer       opb;
michael@0:   int                  mode;
michael@0:  
michael@0:   oggpack_readinit(&opb,op->packet,op->bytes);
michael@0: 
michael@0:   /* Check the packet type */
michael@0:   if(oggpack_read(&opb,1)!=0){
michael@0:     /* Oops.  This is not an audio data packet */
michael@0:     return(OV_ENOTAUDIO);
michael@0:   }
michael@0: 
michael@0:   {
michael@0:     int modebits=0;
michael@0:     int v=ci->modes;
michael@0:     while(v>1){
michael@0:       modebits++;
michael@0:       v>>=1;
michael@0:     }
michael@0: 
michael@0:     /* read our mode and pre/post windowsize */
michael@0:     mode=oggpack_read(&opb,modebits);
michael@0:   }
michael@0:   if(mode==-1)return(OV_EBADPACKET);
michael@0:   return(ci->blocksizes[ci->mode_param[mode]->blockflag]);
michael@0: }
michael@0: 
michael@0: