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 1.4 2000/01/28 14:31:25 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   if(i){
  27     memset(i,0,sizeof(vorbis_info_floor0));
  28     free(i);
  29   }
  30 }
  31 static void free_look(vorbis_look_floor *i){
  32 }
  33
  34 static void pack (vorbis_info_floor *i,oggpack_buffer *opb){
  35   vorbis_info_floor0 *d=(vorbis_info_floor0 *)i;
  36   int j;
  37   _oggpack_write(opb,d->order,8);
  38   _oggpack_write(opb,d->rate,16);
  39   _oggpack_write(opb,d->barkmap,16);
  40   _oggpack_write(opb,d->stages,4);
  41   for(j=0;j<d->stages;j++)
  42     _oggpack_write(opb,d->books[j],8);
  43 }
  44
  45 static vorbis_info_floor *unpack (vorbis_info *vi,oggpack_buffer *opb){
  46   int j;
  47   vorbis_info_floor0 *d=malloc(sizeof(vorbis_info_floor0));
  48   d->order=_oggpack_read(opb,8);
  49   d->rate=_oggpack_read(opb,16);
  50   d->barkmap=_oggpack_read(opb,16);
  51   d->stages=_oggpack_read(opb,4);
  52
  53   if(d->order<1)goto err_out;
  54   if(d->rate<1)goto err_out;
  55   if(d->barkmap<1)goto err_out;
  56   if(d->stages<1)goto err_out;
  57
  58   for(j=0;j<d->stages;j++){
  59     d->books[j]=_oggpack_read(opb,8);
  60     if(d->books[j]<0 || d->books[j]>=vi->books)goto err_out;
  61   }
  62   return(d);
  63  err_out:
  64   free_info(d);
  65   return(NULL);
  66 }
  67
  68 static vorbis_look_floor *look (vorbis_info *vi,vorbis_info_mode *mi,
  69                               vorbis_info_floor *i){
  70
  71 }
  72
  73 static int forward(vorbis_block *vb,vorbis_look_floor *i,
  74                     double *in,double *out){
  75
  76
  77       /* Convert our floor to a set of lpc coefficients
  78       vb->amp[i]=sqrt(vorbis_curve_to_lpc(floor,lpc,vl));
  79
  80       LSP <-> LPC is orthogonal and LSP quantizes more stably
  81       vorbis_lpc_to_lsp(lpc,lsp,vl->m);
  82
  83       code the spectral envelope; mutates the lsp coeffs to reflect
  84       what was actually encoded
  85       _vs_spectrum_encode(vb,vb->amp[i],lsp);
  86
  87       Generate residue from the decoded envelope, which will be
  88          slightly different to the pre-encoding floor due to
  89          quantization.  Slow, yes, but perhaps more accurate
  90
  91       vorbis_lsp_to_lpc(lsp,lpc,vl->m);
  92       vorbis_lpc_to_curve(curve,lpc,vb->amp[i],vl);*/
  93   return(0);
  94 }
  95 static int inverse(vorbis_block *vb,vorbis_look_floor *i,
  96                     double *buf){
  97   return(0);
  98 }
  99
 100 /* export hooks */
 101 vorbis_func_floor floor0_exportbundle={
 102   &pack,&unpack,&look,&free_info,&free_look,&forward,&inverse
 103 };
 104
 105