lib/floor0.c

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE Ogg Vorbis SOFTWARE CODEC SOURCE CODE.  *
   4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS SOURCE IS GOVERNED BY *
   5  * THE GNU PUBLIC LICENSE 2, WHICH IS INCLUDED WITH THIS SOURCE.    *
   6  * PLEASE READ THESE TERMS DISTRIBUTING.                            *
   7  *                                                                  *
   8  * THE OggSQUISH SOURCE CODE IS (C) COPYRIGHT 1994-2000             *
   9  * by Monty <monty@xiph.org> and The XIPHOPHORUS Company            *
  10  * http://www.xiph.org/                                             *
  11  *                                                                  *
  12  ********************************************************************
  13
  14  function: floor backend 0 implementation
  15  last mod: $Id: floor0.c,v 1.3 2000/01/28 09:05:09 xiphmont Exp $
  16
  17  ********************************************************************/
  18
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include "vorbis/codec.h"
  22 #include "bitwise.h"
  23 #include "registry.h"
  24
  25 static void free_info(vorbis_info_floor *i){
  26   vorbis_info_floor0 *d=(vorbis_info_floor0 *)i;
  27   if(d){
  28     if(d->books)free(d->books);
  29     memset(i,0,sizeof(vorbis_info_floor0));
  30   }
  31 }
  32 static void free_look(vorbis_look_floor *i){
  33 }
  34
  35 static void pack (vorbis_info_floor *i,oggpack_buffer *opb){
  36   vorbis_info_floor0 *d=(vorbis_info_floor0 *)i;
  37   int j;
  38   _oggpack_write(opb,d->order,8);
  39   _oggpack_write(opb,d->rate,16);
  40   _oggpack_write(opb,d->barkmap,16);
  41   _oggpack_write(opb,d->stages,8);
  42   for(j=0;j<d->stages;j++)
  43     _oggpack_write(opb,d->books[j],8);
  44 }
  45
  46 static vorbis_info_floor *unpack (vorbis_info *vi,oggpack_buffer *opb){
  47   int j;
  48   vorbis_info_floor0 *d=malloc(sizeof(vorbis_info_floor0));
  49   d->order=_oggpack_read(opb,8);
  50   d->rate=_oggpack_read(opb,16);
  51   d->barkmap=_oggpack_read(opb,16);
  52   d->stages=_oggpack_read(opb,8);
  53
  54   if(d->order<1)goto err_out;
  55   if(d->rate<1)goto err_out;
  56   if(d->barkmap<1)goto err_out;
  57   if(d->stages<1)goto err_out;
  58
  59   d->books=alloca(sizeof(int)*d->stages);
  60   for(j=0;j<d->stages;j++){
  61     d->books[j]=_oggpack_read(opb,8);
  62     if(d->books[j]<0 || d->books[j]>=vi->books)goto err_out;
  63   }
  64   return(d);
  65  err_out:
  66   free_info(d);
  67   return(NULL);
  68 }
  69
  70 static vorbis_look_floor *look (vorbis_info *vi,vorbis_info_mode *mi,
  71                               vorbis_info_floor *i){
  72
  73 }
  74
  75 static int forward(vorbis_block *vb,vorbis_look_floor *i,
  76                     double *in,double *out){
  77
  78
  79       /* Convert our floor to a set of lpc coefficients
  80       vb->amp[i]=sqrt(vorbis_curve_to_lpc(floor,lpc,vl));
  81
  82       LSP <-> LPC is orthogonal and LSP quantizes more stably
  83       vorbis_lpc_to_lsp(lpc,lsp,vl->m);
  84
  85       code the spectral envelope; mutates the lsp coeffs to reflect
  86       what was actually encoded
  87       _vs_spectrum_encode(vb,vb->amp[i],lsp);
  88
  89       Generate residue from the decoded envelope, which will be
  90          slightly different to the pre-encoding floor due to
  91          quantization.  Slow, yes, but perhaps more accurate
  92
  93       vorbis_lsp_to_lpc(lsp,lpc,vl->m);
  94       vorbis_lpc_to_curve(curve,lpc,vb->amp[i],vl);*/
  95   return(0);
  96 }
  97 static int inverse(vorbis_block *vb,vorbis_look_floor *i,
  98                     double *buf){
  99   return(0);
 100 }
 101
 102 /* export hooks */
 103 vorbis_func_floor floor0_exportbundle={
 104   &pack,&unpack,&look,&free_info,&free_look,&forward,&inverse
 105 };
 106
 107