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			222 lines
		
	
	
		
			6.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			222 lines
		
	
	
		
			6.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /********************************************************************
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|  *                                                                  *
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|  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
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|  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
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|  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
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|  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
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|  *                                                                  *
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|  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
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|  * by the Xiph.Org Foundation http://www.xiph.org/                  *
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|  *                                                                  *
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|  ********************************************************************
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| 
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|  function: floor backend 0 implementation
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|  last mod: $Id: floor0.c 18184 2012-02-03 20:55:12Z xiphmont $
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| 
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|  ********************************************************************/
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| 
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| #include <stdlib.h>
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| #include <string.h>
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| #include <math.h>
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| #include <ogg/ogg.h>
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| #include "vorbis/codec.h"
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| #include "codec_internal.h"
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| #include "registry.h"
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| #include "lpc.h"
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| #include "lsp.h"
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| #include "codebook.h"
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| #include "scales.h"
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| #include "misc.h"
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| #include "os.h"
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| 
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| #include "misc.h"
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| #include <stdio.h>
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| 
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| typedef struct {
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|   int ln;
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|   int  m;
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|   int **linearmap;
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|   int  n[2];
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| 
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|   vorbis_info_floor0 *vi;
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| 
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|   long bits;
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|   long frames;
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| } vorbis_look_floor0;
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| 
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| 
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| /***********************************************/
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| 
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| static void floor0_free_info(vorbis_info_floor *i){
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|   vorbis_info_floor0 *info=(vorbis_info_floor0 *)i;
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|   if(info){
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|     memset(info,0,sizeof(*info));
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|     _ogg_free(info);
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|   }
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| }
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| 
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| static void floor0_free_look(vorbis_look_floor *i){
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|   vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
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|   if(look){
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| 
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|     if(look->linearmap){
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| 
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|       if(look->linearmap[0])_ogg_free(look->linearmap[0]);
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|       if(look->linearmap[1])_ogg_free(look->linearmap[1]);
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| 
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|       _ogg_free(look->linearmap);
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|     }
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|     memset(look,0,sizeof(*look));
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|     _ogg_free(look);
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|   }
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| }
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| 
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| static vorbis_info_floor *floor0_unpack (vorbis_info *vi,oggpack_buffer *opb){
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|   codec_setup_info     *ci=vi->codec_setup;
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|   int j;
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| 
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|   vorbis_info_floor0 *info=_ogg_malloc(sizeof(*info));
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|   info->order=oggpack_read(opb,8);
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|   info->rate=oggpack_read(opb,16);
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|   info->barkmap=oggpack_read(opb,16);
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|   info->ampbits=oggpack_read(opb,6);
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|   info->ampdB=oggpack_read(opb,8);
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|   info->numbooks=oggpack_read(opb,4)+1;
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| 
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|   if(info->order<1)goto err_out;
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|   if(info->rate<1)goto err_out;
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|   if(info->barkmap<1)goto err_out;
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|   if(info->numbooks<1)goto err_out;
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| 
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|   for(j=0;j<info->numbooks;j++){
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|     info->books[j]=oggpack_read(opb,8);
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|     if(info->books[j]<0 || info->books[j]>=ci->books)goto err_out;
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|     if(ci->book_param[info->books[j]]->maptype==0)goto err_out;
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|     if(ci->book_param[info->books[j]]->dim<1)goto err_out;
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|   }
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|   return(info);
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| 
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|  err_out:
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|   floor0_free_info(info);
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|   return(NULL);
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| }
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| 
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| /* initialize Bark scale and normalization lookups.  We could do this
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|    with static tables, but Vorbis allows a number of possible
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|    combinations, so it's best to do it computationally.
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| 
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|    The below is authoritative in terms of defining scale mapping.
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|    Note that the scale depends on the sampling rate as well as the
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|    linear block and mapping sizes */
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| 
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| static void floor0_map_lazy_init(vorbis_block      *vb,
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|                                  vorbis_info_floor *infoX,
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|                                  vorbis_look_floor0 *look){
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|   if(!look->linearmap[vb->W]){
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|     vorbis_dsp_state   *vd=vb->vd;
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|     vorbis_info        *vi=vd->vi;
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|     codec_setup_info   *ci=vi->codec_setup;
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|     vorbis_info_floor0 *info=(vorbis_info_floor0 *)infoX;
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|     int W=vb->W;
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|     int n=ci->blocksizes[W]/2,j;
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| 
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|     /* we choose a scaling constant so that:
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|        floor(bark(rate/2-1)*C)=mapped-1
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|      floor(bark(rate/2)*C)=mapped */
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|     float scale=look->ln/toBARK(info->rate/2.f);
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| 
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|     /* the mapping from a linear scale to a smaller bark scale is
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|        straightforward.  We do *not* make sure that the linear mapping
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|        does not skip bark-scale bins; the decoder simply skips them and
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|        the encoder may do what it wishes in filling them.  They're
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|        necessary in some mapping combinations to keep the scale spacing
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|        accurate */
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|     look->linearmap[W]=_ogg_malloc((n+1)*sizeof(**look->linearmap));
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|     for(j=0;j<n;j++){
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|       int val=floor( toBARK((info->rate/2.f)/n*j)
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|                      *scale); /* bark numbers represent band edges */
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|       if(val>=look->ln)val=look->ln-1; /* guard against the approximation */
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|       look->linearmap[W][j]=val;
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|     }
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|     look->linearmap[W][j]=-1;
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|     look->n[W]=n;
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|   }
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| }
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| 
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| static vorbis_look_floor *floor0_look(vorbis_dsp_state *vd,
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|                                       vorbis_info_floor *i){
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|   vorbis_info_floor0 *info=(vorbis_info_floor0 *)i;
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|   vorbis_look_floor0 *look=_ogg_calloc(1,sizeof(*look));
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|   look->m=info->order;
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|   look->ln=info->barkmap;
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|   look->vi=info;
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| 
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|   look->linearmap=_ogg_calloc(2,sizeof(*look->linearmap));
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| 
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|   return look;
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| }
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| 
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| static void *floor0_inverse1(vorbis_block *vb,vorbis_look_floor *i){
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|   vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
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|   vorbis_info_floor0 *info=look->vi;
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|   int j,k;
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| 
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|   int ampraw=oggpack_read(&vb->opb,info->ampbits);
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|   if(ampraw>0){ /* also handles the -1 out of data case */
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|     long maxval=(1<<info->ampbits)-1;
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|     float amp=(float)ampraw/maxval*info->ampdB;
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|     int booknum=oggpack_read(&vb->opb,_ilog(info->numbooks));
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| 
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|     if(booknum!=-1 && booknum<info->numbooks){ /* be paranoid */
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|       codec_setup_info  *ci=vb->vd->vi->codec_setup;
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|       codebook *b=ci->fullbooks+info->books[booknum];
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|       float last=0.f;
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| 
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|       /* the additional b->dim is a guard against any possible stack
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|          smash; b->dim is provably more than we can overflow the
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|          vector */
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|       float *lsp=_vorbis_block_alloc(vb,sizeof(*lsp)*(look->m+b->dim+1));
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| 
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|       if(vorbis_book_decodev_set(b,lsp,&vb->opb,look->m)==-1)goto eop;
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|       for(j=0;j<look->m;){
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|         for(k=0;j<look->m && k<b->dim;k++,j++)lsp[j]+=last;
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|         last=lsp[j-1];
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|       }
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| 
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|       lsp[look->m]=amp;
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|       return(lsp);
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|     }
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|   }
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|  eop:
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|   return(NULL);
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| }
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| 
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| static int floor0_inverse2(vorbis_block *vb,vorbis_look_floor *i,
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|                            void *memo,float *out){
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|   vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
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|   vorbis_info_floor0 *info=look->vi;
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| 
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|   floor0_map_lazy_init(vb,info,look);
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| 
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|   if(memo){
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|     float *lsp=(float *)memo;
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|     float amp=lsp[look->m];
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| 
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|     /* take the coefficients back to a spectral envelope curve */
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|     vorbis_lsp_to_curve(out,
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|                         look->linearmap[vb->W],
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|                         look->n[vb->W],
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|                         look->ln,
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|                         lsp,look->m,amp,(float)info->ampdB);
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|     return(1);
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|   }
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|   memset(out,0,sizeof(*out)*look->n[vb->W]);
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|   return(0);
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| }
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| 
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| /* export hooks */
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| const vorbis_func_floor floor0_exportbundle={
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|   NULL,&floor0_unpack,&floor0_look,&floor0_free_info,
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|   &floor0_free_look,&floor0_inverse1,&floor0_inverse2
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| };
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