cannam@86: /********************************************************************
cannam@86:  *                                                                  *
cannam@86:  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
cannam@86:  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
cannam@86:  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
cannam@86:  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
cannam@86:  *                                                                  *
cannam@86:  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
cannam@86:  * by the Xiph.Org Foundation http://www.xiph.org/                  *
cannam@86:  *                                                                  *
cannam@86:  ********************************************************************
cannam@86: 
cannam@86:  function: single-block PCM synthesis
cannam@86:  last mod: $Id: synthesis.c 17474 2010-09-30 03:41:41Z gmaxwell $
cannam@86: 
cannam@86:  ********************************************************************/
cannam@86: 
cannam@86: #include <stdio.h>
cannam@86: #include <ogg/ogg.h>
cannam@86: #include "vorbis/codec.h"
cannam@86: #include "codec_internal.h"
cannam@86: #include "registry.h"
cannam@86: #include "misc.h"
cannam@86: #include "os.h"
cannam@86: 
cannam@86: int vorbis_synthesis(vorbis_block *vb,ogg_packet *op){
cannam@86:   vorbis_dsp_state     *vd= vb ? vb->vd : 0;
cannam@86:   private_state        *b= vd ? vd->backend_state : 0;
cannam@86:   vorbis_info          *vi= vd ? vd->vi : 0;
cannam@86:   codec_setup_info     *ci= vi ? vi->codec_setup : 0;
cannam@86:   oggpack_buffer       *opb=vb ? &vb->opb : 0;
cannam@86:   int                   type,mode,i;
cannam@86: 
cannam@86:   if (!vd || !b || !vi || !ci || !opb) {
cannam@86:     return OV_EBADPACKET;
cannam@86:   }
cannam@86: 
cannam@86:   /* first things first.  Make sure decode is ready */
cannam@86:   _vorbis_block_ripcord(vb);
cannam@86:   oggpack_readinit(opb,op->packet,op->bytes);
cannam@86: 
cannam@86:   /* Check the packet type */
cannam@86:   if(oggpack_read(opb,1)!=0){
cannam@86:     /* Oops.  This is not an audio data packet */
cannam@86:     return(OV_ENOTAUDIO);
cannam@86:   }
cannam@86: 
cannam@86:   /* read our mode and pre/post windowsize */
cannam@86:   mode=oggpack_read(opb,b->modebits);
cannam@86:   if(mode==-1){
cannam@86:     return(OV_EBADPACKET);
cannam@86:   }
cannam@86: 
cannam@86:   vb->mode=mode;
cannam@86:   if(!ci->mode_param[mode]){
cannam@86:     return(OV_EBADPACKET);
cannam@86:   }
cannam@86: 
cannam@86:   vb->W=ci->mode_param[mode]->blockflag;
cannam@86:   if(vb->W){
cannam@86: 
cannam@86:     /* this doesn;t get mapped through mode selection as it's used
cannam@86:        only for window selection */
cannam@86:     vb->lW=oggpack_read(opb,1);
cannam@86:     vb->nW=oggpack_read(opb,1);
cannam@86:     if(vb->nW==-1){
cannam@86:       return(OV_EBADPACKET);
cannam@86:     }
cannam@86:   }else{
cannam@86:     vb->lW=0;
cannam@86:     vb->nW=0;
cannam@86:   }
cannam@86: 
cannam@86:   /* more setup */
cannam@86:   vb->granulepos=op->granulepos;
cannam@86:   vb->sequence=op->packetno;
cannam@86:   vb->eofflag=op->e_o_s;
cannam@86: 
cannam@86:   /* alloc pcm passback storage */
cannam@86:   vb->pcmend=ci->blocksizes[vb->W];
cannam@86:   vb->pcm=_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels);
cannam@86:   for(i=0;i<vi->channels;i++)
cannam@86:     vb->pcm[i]=_vorbis_block_alloc(vb,vb->pcmend*sizeof(*vb->pcm[i]));
cannam@86: 
cannam@86:   /* unpack_header enforces range checking */
cannam@86:   type=ci->map_type[ci->mode_param[mode]->mapping];
cannam@86: 
cannam@86:   return(_mapping_P[type]->inverse(vb,ci->map_param[ci->mode_param[mode]->
cannam@86:                                                    mapping]));
cannam@86: }
cannam@86: 
cannam@86: /* used to track pcm position without actually performing decode.
cannam@86:    Useful for sequential 'fast forward' */
cannam@86: int vorbis_synthesis_trackonly(vorbis_block *vb,ogg_packet *op){
cannam@86:   vorbis_dsp_state     *vd=vb->vd;
cannam@86:   private_state        *b=vd->backend_state;
cannam@86:   vorbis_info          *vi=vd->vi;
cannam@86:   codec_setup_info     *ci=vi->codec_setup;
cannam@86:   oggpack_buffer       *opb=&vb->opb;
cannam@86:   int                   mode;
cannam@86: 
cannam@86:   /* first things first.  Make sure decode is ready */
cannam@86:   _vorbis_block_ripcord(vb);
cannam@86:   oggpack_readinit(opb,op->packet,op->bytes);
cannam@86: 
cannam@86:   /* Check the packet type */
cannam@86:   if(oggpack_read(opb,1)!=0){
cannam@86:     /* Oops.  This is not an audio data packet */
cannam@86:     return(OV_ENOTAUDIO);
cannam@86:   }
cannam@86: 
cannam@86:   /* read our mode and pre/post windowsize */
cannam@86:   mode=oggpack_read(opb,b->modebits);
cannam@86:   if(mode==-1)return(OV_EBADPACKET);
cannam@86: 
cannam@86:   vb->mode=mode;
cannam@86:   if(!ci->mode_param[mode]){
cannam@86:     return(OV_EBADPACKET);
cannam@86:   }
cannam@86:   
cannam@86:   vb->W=ci->mode_param[mode]->blockflag;
cannam@86:   if(vb->W){
cannam@86:     vb->lW=oggpack_read(opb,1);
cannam@86:     vb->nW=oggpack_read(opb,1);
cannam@86:     if(vb->nW==-1)   return(OV_EBADPACKET);
cannam@86:   }else{
cannam@86:     vb->lW=0;
cannam@86:     vb->nW=0;
cannam@86:   }
cannam@86: 
cannam@86:   /* more setup */
cannam@86:   vb->granulepos=op->granulepos;
cannam@86:   vb->sequence=op->packetno;
cannam@86:   vb->eofflag=op->e_o_s;
cannam@86: 
cannam@86:   /* no pcm */
cannam@86:   vb->pcmend=0;
cannam@86:   vb->pcm=NULL;
cannam@86: 
cannam@86:   return(0);
cannam@86: }
cannam@86: 
cannam@86: long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
cannam@86:   codec_setup_info     *ci=vi->codec_setup;
cannam@86:   oggpack_buffer       opb;
cannam@86:   int                  mode;
cannam@86: 
cannam@86:   oggpack_readinit(&opb,op->packet,op->bytes);
cannam@86: 
cannam@86:   /* Check the packet type */
cannam@86:   if(oggpack_read(&opb,1)!=0){
cannam@86:     /* Oops.  This is not an audio data packet */
cannam@86:     return(OV_ENOTAUDIO);
cannam@86:   }
cannam@86: 
cannam@86:   {
cannam@86:     int modebits=0;
cannam@86:     int v=ci->modes;
cannam@86:     while(v>1){
cannam@86:       modebits++;
cannam@86:       v>>=1;
cannam@86:     }
cannam@86: 
cannam@86:     /* read our mode and pre/post windowsize */
cannam@86:     mode=oggpack_read(&opb,modebits);
cannam@86:   }
cannam@86:   if(mode==-1)return(OV_EBADPACKET);
cannam@86:   return(ci->blocksizes[ci->mode_param[mode]->blockflag]);
cannam@86: }
cannam@86: 
cannam@86: int vorbis_synthesis_halfrate(vorbis_info *vi,int flag){
cannam@86:   /* set / clear half-sample-rate mode */
cannam@86:   codec_setup_info     *ci=vi->codec_setup;
cannam@86: 
cannam@86:   /* right now, our MDCT can't handle < 64 sample windows. */
cannam@86:   if(ci->blocksizes[0]<=64 && flag)return -1;
cannam@86:   ci->halfrate_flag=(flag?1:0);
cannam@86:   return 0;
cannam@86: }
cannam@86: 
cannam@86: int vorbis_synthesis_halfrate_p(vorbis_info *vi){
cannam@86:   codec_setup_info     *ci=vi->codec_setup;
cannam@86:   return ci->halfrate_flag;
cannam@86: }