зеркало из https://github.com/mozilla/gecko-dev.git
84 строки
2.1 KiB
C
84 строки
2.1 KiB
C
/********************************************************************
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* *
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* THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE. *
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* *
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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 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002 *
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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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function: window functions
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********************************************************************/
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#include <stdlib.h>
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#include <math.h>
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#include "misc.h"
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#include "window.h"
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#include "window_lookup.h"
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const void *_vorbis_window(int type, int left){
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switch(type){
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case 0:
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switch(left){
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case 32:
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return vwin64;
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case 64:
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return vwin128;
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case 128:
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return vwin256;
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case 256:
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return vwin512;
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case 512:
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return vwin1024;
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case 1024:
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return vwin2048;
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case 2048:
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return vwin4096;
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case 4096:
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return vwin8192;
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default:
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return(0);
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}
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break;
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default:
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return(0);
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}
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}
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void _vorbis_apply_window(ogg_int32_t *d,const void *window_p[2],
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long *blocksizes,
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int lW,int W,int nW){
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LOOKUP_T *window[2]={window_p[0],window_p[1]};
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long n=blocksizes[W];
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long ln=blocksizes[lW];
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long rn=blocksizes[nW];
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long leftbegin=n/4-ln/4;
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long leftend=leftbegin+ln/2;
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long rightbegin=n/2+n/4-rn/4;
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long rightend=rightbegin+rn/2;
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int i,p;
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for(i=0;i<leftbegin;i++)
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d[i]=0;
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for(p=0;i<leftend;i++,p++)
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d[i]=MULT31(d[i],window[lW][p]);
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for(i=rightbegin,p=rn/2-1;i<rightend;i++,p--)
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d[i]=MULT31(d[i],window[nW][p]);
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for(;i<n;i++)
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d[i]=0;
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}
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