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 1.2 2000/01/22 13:28:19 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 pack (vorbis_info_floor *i,oggpack_buffer *opb){
  26   vorbis_info_floor0 *d=(vorbis_info_floor0 *)i;
  27   int j;
  28   _oggpack_write(opb,d->order,8);
  29   _oggpack_write(opb,d->rate,16);
  30   _oggpack_write(opb,d->barkmap,16);
  31   _oggpack_write(opb,d->stages,8);
  32   for(j=0;j<d->stages;j++)
  33     _oggpack_write(opb,d->books[j],8);
  34 }
  35
  36 static vorbis_info_floor *unpack (vorbis_info *vi,oggpack_buffer *opb){
  37   int j;
  38   vorbis_info_floor0 *d=malloc(sizeof(vorbis_info_floor0));
  39   d->order=_oggpack_read(opb,8);
  40   d->rate=_oggpack_read(opb,16);
  41   d->barkmap=_oggpack_read(opb,16);
  42   d->stages=_oggpack_read(opb,8);
  43
  44   if(d->order<1)goto err_out;
  45   if(d->rate<1)goto err_out;
  46   if(d->barkmap<1)goto err_out;
  47   if(d->stages<1)goto err_out;
  48
  49   d->books=alloca(sizeof(int)*d->stages);
  50   for(j=0;j<d->stages;j++){
  51     d->books[j]=_oggpack_read(opb,8);
  52     if(d->books[j]<0 || d->books[j]>=vi->books)goto err_out;
  53   }
  54   return(d);
  55  err_out:
  56   free_info(d);
  57   return(NULL);
  58 }
  59
  60 static vorbis_look_floor *look (vorbis_info *vi,vorbis_info_mode *mi,
  61                               vorbis_info_floor *i){
  62
  63 }
  64 static void free_info(vorbis_info_floor *i){
  65   vorbis_info_floor0 *d=(vorbis_info_floor0 *)i;
  66   if(d){
  67     if(d->books)free(d->books);
  68     memset(i,0,sizeof(vorbis_info_floor0));
  69   }
  70 }
  71 static void free_look(vorbis_look_floor *i){
  72 }
  73
  74 static void forward(vorbis_block *vb,vorbis_look_floor *i,
  75                     double *in,double *out){
  76
  77
  78       /* Convert our floor to a set of lpc coefficients
  79       vb->amp[i]=sqrt(vorbis_curve_to_lpc(floor,lpc,vl));
  80
  81       LSP <-> LPC is orthogonal and LSP quantizes more stably
  82       vorbis_lpc_to_lsp(lpc,lsp,vl->m);
  83
  84       code the spectral envelope; mutates the lsp coeffs to reflect
  85       what was actually encoded
  86       _vs_spectrum_encode(vb,vb->amp[i],lsp);
  87
  88       Generate residue from the decoded envelope, which will be
  89          slightly different to the pre-encoding floor due to
  90          quantization.  Slow, yes, but perhaps more accurate
  91
  92       vorbis_lsp_to_lpc(lsp,lpc,vl->m);
  93       vorbis_lpc_to_curve(curve,lpc,vb->amp[i],vl);*/
  94   return(0);
  95 }
  96 static void inverse(vorbis_block *vb,vorbis_look_floor *i,
  97                     double *in,double *out){
  98   return(0);
  99 }
 100
 101 /* export hooks */
 102 vorbis_func_floor floor0_exportbundle={
 103   &pack,&unpack,&look,&free_info,&free_look,&forward,&inverse
 104 };
 105
 106