comparison src/libvorbis-1.3.3/lib/synthesis.c @ 1:05aa0afa9217

Bring in flac, ogg, vorbis

+/********************************************************************
+ *                                                                  *
+ * 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 http://www.xiph.org/                  *
+ *                                                                  *
+ ********************************************************************
+
+ function: single-block PCM synthesis
+ last mod: $Id: synthesis.c 17474 2010-09-30 03:41:41Z gmaxwell $
+
+ ********************************************************************/
+
+#include <stdio.h>
+#include <ogg/ogg.h>
+#include "vorbis/codec.h"
+#include "codec_internal.h"
+#include "registry.h"
+#include "misc.h"
+#include "os.h"
+
+int vorbis_synthesis(vorbis_block *vb,ogg_packet *op){
+  vorbis_dsp_state     *vd= vb ? vb->vd : 0;
+  private_state        *b= vd ? vd->backend_state : 0;
+  vorbis_info          *vi= vd ? vd->vi : 0;
+  codec_setup_info     *ci= vi ? vi->codec_setup : 0;
+  oggpack_buffer       *opb=vb ? &vb->opb : 0;
+  int                   type,mode,i;
+
+  if (!vd || !b || !vi || !ci || !opb) {
+    return OV_EBADPACKET;
+  }
+
+  /* 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(OV_ENOTAUDIO);
+  }
+
+  /* read our mode and pre/post windowsize */
+  mode=oggpack_read(opb,b->modebits);
+  if(mode==-1){
+    return(OV_EBADPACKET);
+  }
+
+  vb->mode=mode;
+  if(!ci->mode_param[mode]){
+    return(OV_EBADPACKET);
+  }
+
+  vb->W=ci->mode_param[mode]->blockflag;
+  if(vb->W){
+
+    /* this doesn;t get mapped through mode selection as it's used
+       only for window selection */
+    vb->lW=oggpack_read(opb,1);
+    vb->nW=oggpack_read(opb,1);
+    if(vb->nW==-1){
+      return(OV_EBADPACKET);
+    }
+  }else{
+    vb->lW=0;
+    vb->nW=0;
+  }
+
+  /* more setup */
+  vb->granulepos=op->granulepos;
+  vb->sequence=op->packetno;
+  vb->eofflag=op->e_o_s;
+
+  /* alloc pcm passback storage */
+  vb->pcmend=ci->blocksizes[vb->W];
+  vb->pcm=_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels);
+  for(i=0;i<vi->channels;i++)
+    vb->pcm[i]=_vorbis_block_alloc(vb,vb->pcmend*sizeof(*vb->pcm[i]));
+
+  /* unpack_header enforces range checking */
+  type=ci->map_type[ci->mode_param[mode]->mapping];
+
+  return(_mapping_P[type]->inverse(vb,ci->map_param[ci->mode_param[mode]->
+                                                   mapping]));
+}
+
+/* used to track pcm position without actually performing decode.
+   Useful for sequential 'fast forward' */
+int vorbis_synthesis_trackonly(vorbis_block *vb,ogg_packet *op){
+  vorbis_dsp_state     *vd=vb->vd;
+  private_state        *b=vd->backend_state;
+  vorbis_info          *vi=vd->vi;
+  codec_setup_info     *ci=vi->codec_setup;
+  oggpack_buffer       *opb=&vb->opb;
+  int                   mode;
+
+  /* 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(OV_ENOTAUDIO);
+  }
+
+  /* read our mode and pre/post windowsize */
+  mode=oggpack_read(opb,b->modebits);
+  if(mode==-1)return(OV_EBADPACKET);
+
+  vb->mode=mode;
+  if(!ci->mode_param[mode]){
+    return(OV_EBADPACKET);
+  }
+  
+  vb->W=ci->mode_param[mode]->blockflag;
+  if(vb->W){
+    vb->lW=oggpack_read(opb,1);
+    vb->nW=oggpack_read(opb,1);
+    if(vb->nW==-1)   return(OV_EBADPACKET);
+  }else{
+    vb->lW=0;
+    vb->nW=0;
+  }
+
+  /* more setup */
+  vb->granulepos=op->granulepos;
+  vb->sequence=op->packetno;
+  vb->eofflag=op->e_o_s;
+
+  /* no pcm */
+  vb->pcmend=0;
+  vb->pcm=NULL;
+
+  return(0);
+}
+
+long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
+  codec_setup_info     *ci=vi->codec_setup;
+  oggpack_buffer       opb;
+  int                  mode;
+
+  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(OV_ENOTAUDIO);
+  }
+
+  {
+    int modebits=0;
+    int v=ci->modes;
+    while(v>1){
+      modebits++;
+      v>>=1;
+    }
+
+    /* read our mode and pre/post windowsize */
+    mode=oggpack_read(&opb,modebits);
+  }
+  if(mode==-1)return(OV_EBADPACKET);
+  return(ci->blocksizes[ci->mode_param[mode]->blockflag]);
+}
+
+int vorbis_synthesis_halfrate(vorbis_info *vi,int flag){
+  /* set / clear half-sample-rate mode */
+  codec_setup_info     *ci=vi->codec_setup;
+
+  /* right now, our MDCT can't handle < 64 sample windows. */
+  if(ci->blocksizes[0]<=64 && flag)return -1;
+  ci->halfrate_flag=(flag?1:0);
+  return 0;
+}
+
+int vorbis_synthesis_halfrate_p(vorbis_info *vi){
+  codec_setup_info     *ci=vi->codec_setup;
+  return ci->halfrate_flag;
+}