1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
/********************************************************************
* *
* THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE. *
* *
* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
* *
* THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002 *
* BY THE Xiph.Org FOUNDATION http://www.xiph.org/ *
* *
********************************************************************
function: window functions
********************************************************************/
#include "config-tremor.h"
#include <string.h>
#include <math.h>
#include "os.h"
#include "misc.h"
#include "window.h"
#include "window_lookup.h"
const void *_vorbis_window(int type, int left){
switch(type){
case 0:
switch(left){
case 32:
return vwin64;
case 64:
return vwin128;
case 128:
return vwin256;
case 256:
return vwin512;
case 512:
return vwin1024;
case 1024:
return vwin2048;
case 2048:
return vwin4096;
case 4096:
return vwin8192;
default:
return(0);
}
break;
default:
return(0);
}
}
void _vorbis_apply_window(ogg_int32_t *d,const void *window_p[2],
long *blocksizes,
int lW,int W,int nW){
LOOKUP_T *window[2]={window_p[0],window_p[1]};
long n=blocksizes[W];
long ln=blocksizes[lW];
long rn=blocksizes[nW];
long leftbegin=n/4-ln/4;
long leftend=leftbegin+ln/2;
long rightbegin=n/2+n/4-rn/4;
long rightend=rightbegin+rn/2;
/* Following memset is not required - we are careful to only overlap/add the
regions that geniunely overlap in the window region, and the portions
outside that region are not added (so don't need to be zerod). see block.c
memset((void *)&d[0], 0, sizeof(ogg_int32_t)*leftbegin); */
vect_mult_fw(&d[leftbegin], &window[lW][0], leftend-leftbegin);
vect_mult_bw(&d[rightbegin], &window[nW][rn/2-1], rightend-rightbegin);
/* Again - memset not needed
memset((void *)&d[rightend], 0, sizeof(ogg_int32_t)*(n-rightend)); */
}
|
