apps/codecs/Tremor/synthesis.c

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *
   4  *                                                                  *
   5  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
   6  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
   7  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
   8  *                                                                  *
   9  * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003    *
  10  * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
  11  *                                                                  *
  12  ********************************************************************
  13
  14  function: single-block PCM synthesis
  15  last mod: $Id$
  16
  17  ********************************************************************/
  18
  19 #include <stdio.h>
  20 #include "ogg.h"
  21 #include "ivorbiscodec.h"
  22 #include "codec_internal.h"
  23 #include "registry.h"
  24 #include "misc.h"
  25 #include "os.h"
  26
  27
  28 /* IRAM buffer keep the block pcm data; only for windows size upto 2048
  29    for space restrictions.
  30    libVorbis 1.1 Oggenc doesn't use larger windows anyway. */
  31 /* max 2 channels on the ihp-1xx (stereo), 2048 samples (2*2048*4=16Kb)  */
  32 #define IRAM_PCM_END      2048
  33 #define CHANNELS          2
  34
  35 static ogg_int32_t *ipcm_vect[CHANNELS] IBSS_ATTR;
  36 static ogg_int32_t ipcm_buff[CHANNELS*IRAM_PCM_END] IBSS_ATTR LINE_ATTR;
  37
  38 int vorbis_synthesis(vorbis_block *vb,ogg_packet *op,int decodep)
  39     ICODE_ATTR_TREMOR_NOT_MDCT;
  40 int vorbis_synthesis(vorbis_block *vb,ogg_packet *op,int decodep){
  41   vorbis_dsp_state     *vd=vb->vd;
  42   private_state        *b=(private_state *)vd->backend_state;
  43   vorbis_info          *vi=vd->vi;
  44   codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;
  45   oggpack_buffer       *opb=&vb->opb;
  46   int                   type,mode,i;
  47
  48   /* first things first.  Make sure decode is ready */
  49   _vorbis_block_ripcord(vb);
  50   oggpack_readinit(opb,op->packet);
  51
  52   /* Check the packet type */
  53   if(oggpack_read(opb,1)!=0){
  54     /* Oops.  This is not an audio data packet */
  55     return(OV_ENOTAUDIO);
  56   }
  57
  58   /* read our mode and pre/post windowsize */
  59   mode=oggpack_read(opb,b->modebits);
  60   if(mode==-1)return(OV_EBADPACKET);
  61
  62   vb->mode=mode;
  63   vb->W=ci->mode_param[mode]->blockflag;
  64   if(vb->W){
  65     vb->lW=oggpack_read(opb,1);
  66     vb->nW=oggpack_read(opb,1);
  67     if(vb->nW==-1)   return(OV_EBADPACKET);
  68   }else{
  69     vb->lW=0;
  70     vb->nW=0;
  71   }
  72
  73   /* more setup */
  74   vb->granulepos=op->granulepos;
  75   vb->sequence=op->packetno-3; /* first block is third packet */
  76   vb->eofflag=op->e_o_s;
  77
  78   if(decodep && vi->channels<=CHANNELS){
  79     /* alloc pcm passback storage */
  80     vb->pcmend=ci->blocksizes[vb->W];
  81     if (vb->pcmend<=IRAM_PCM_END) {
  82       /* use statically allocated iram buffer */
  83       vb->pcm = ipcm_vect;
  84       for(i=0; i<CHANNELS; i++)
  85         vb->pcm[i] = &ipcm_buff[i*IRAM_PCM_END];
  86     } else {
  87       /* dynamic allocation (slower) */
  88       vb->pcm=(ogg_int32_t **)_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels);
  89       for(i=0;i<vi->channels;i++)
  90         vb->pcm[i]=(ogg_int32_t *)_vorbis_block_alloc(vb,vb->pcmend*sizeof(*vb->pcm[i]));
  91     }
  92
  93     /* unpack_header enforces range checking */
  94     type=ci->map_type[ci->mode_param[mode]->mapping];
  95
  96     return(_mapping_P[type]->inverse(vb,b->mode[mode]));
  97   }else{
  98     /* no pcm */
  99     vb->pcmend=0;
 100     vb->pcm=NULL;
 101
 102     return(0);
 103   }
 104 }
 105
 106 long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
 107   codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;
 108   oggpack_buffer       opb;
 109   int                  mode;
 110
 111   oggpack_readinit(&opb,op->packet);
 112
 113   /* Check the packet type */
 114   if(oggpack_read(&opb,1)!=0){
 115     /* Oops.  This is not an audio data packet */
 116     return(OV_ENOTAUDIO);
 117   }
 118
 119   {
 120     int modebits=0;
 121     int v=ci->modes;
 122     while(v>1){
 123       modebits++;
 124       v>>=1;
 125     }
 126
 127     /* read our mode and pre/post windowsize */
 128     mode=oggpack_read(&opb,modebits);
 129   }
 130   if(mode==-1)return(OV_EBADPACKET);
 131   return(ci->blocksizes[ci->mode_param[mode]->blockflag]);
 132 }
 133
 134