--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libtremor/synthesis.c	Sun Apr 24 22:57:57 2011 +0200
@@ -0,0 +1,113 @@
+/********************************************************************
+ *                                                                  *
+ * THIS FILE IS PART OF THE OggVorbis 'TREMOR' 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 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003    *
+ * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
+ *                                                                  *
+ ********************************************************************
+
+ function: single-block PCM synthesis
+ last mod: $Id: synthesis.c,v 1.4 2003/03/29 03:07:21 xiphmont Exp $
+
+ ********************************************************************/
+
+#include <stdio.h>
+#include "ogg.h"
+#include "ivorbiscodec.h"
+#include "codec_internal.h"
+#include "registry.h"
+#include "misc.h"
+#include "block.h"
+
+int vorbis_synthesis(vorbis_block *vb,ogg_packet *op,int decodep){
+  vorbis_dsp_state     *vd=vb->vd;
+  private_state        *b=(private_state *)vd->backend_state;
+  vorbis_info          *vi=vd->vi;
+  codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;
+  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);
+
+  /* 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;
+  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-3; /* first block is third packet */
+  vb->eofflag=op->e_o_s;
+
+  if(decodep){
+    /* alloc pcm passback storage */
+    vb->pcmend=ci->blocksizes[vb->W];
+    vb->pcm=(ogg_int32_t **)_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels);
+    for(i=0;i<vi->channels;i++)
+      vb->pcm[i]=(ogg_int32_t *)_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,b->mode[mode]));
+  }else{
+    /* no pcm */
+    vb->pcmend=0;
+    vb->pcm=NULL;
+    
+    return(0);
+  }
+}
+
+long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
+  codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;
+  oggpack_buffer       opb;
+  int                  mode;
+ 
+  oggpack_readinit(&opb,op->packet);
+
+  /* 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]);
+}
+
+