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extend ff_inverse[], and fix its documentation

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Originally committed as revision 19942 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Loren Merritt 2009-09-21 03:01:57 +00:00
parent d650574e68
commit 1a918c08e4
2 changed files with 5 additions and 3 deletions
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6
libavcodec/dsputil.c
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@ -110,8 +110,9 @@ const uint8_t ff_alternate_vertical_scan[64] = {
38, 46, 54, 62, 39, 47, 55, 63,
};
/* a*inverse[b]>>32 == a/b for all 0<=a<=65536 && 2<=b<=255 */
const uint32_t ff_inverse[256]={
/* a*inverse[b]>>32 == a/b for all 0<=a<=16909558 && 2<=b<=256
* for a>16909558, is an overestimate by less than 1 part in 1<<24 */
const uint32_t ff_inverse[257]={
0, 4294967295U,2147483648U,1431655766, 1073741824, 858993460, 715827883, 613566757,
536870912, 477218589, 429496730, 390451573, 357913942, 330382100, 306783379, 286331154,
268435456, 252645136, 238609295, 226050911, 214748365, 204522253, 195225787, 186737709,
@ -144,6 +145,7 @@ const uint32_t ff_inverse[256]={
18512791, 18433337, 18354562, 18276457, 18199014, 18122225, 18046082, 17970575,
17895698, 17821442, 17747799, 17674763, 17602325, 17530479, 17459217, 17388532,
17318417, 17248865, 17179870, 17111424, 17043522, 16976156, 16909321, 16843010,
16777216
};
/* Input permutation for the simple_idct_mmx */

2
libavutil/internal.h
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@ -124,7 +124,7 @@
/* math */
extern const uint32_t ff_inverse[256];
extern const uint32_t ff_inverse[257];
#if ARCH_X86
# define FASTDIV(a,b) \