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fastdiv patch by (BERO <bero at geocities dot co dot jp>) with fixes & cleanup by me 

Originally committed as revision 1879 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
BERO 2003-05-14 15:12:13 +00:00 committed by Michael Niedermayer
parent b82cdc7278
commit d4961b3523
4 changed files with 26 additions and 22 deletions
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19
libavcodec/common.h
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@ -197,6 +197,25 @@ inline void dprintf(const char* fmt,...) {}
#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
extern const uint32_t inverse[256];
#ifdef ARCH_X86
# define FASTDIV(a,b) \
({\
int ret,dmy;\
asm volatile(\
"mull %3"\
:"=d"(ret),"=a"(dmy)\
:"1"(a),"g"(inverse[b])\
);\
ret;\
})
#elif defined(CONFIG_FASTDIV)
# define FASTDIV(a,b) ((uint32_t)((((uint64_t)a)*inverse[b])>>32))
#else
# define FASTDIV(a,b) ((a)/(b))
#endif
#ifdef ARCH_X86
// avoid +32 for shift optimization (gcc should do that ...)
static inline int32_t NEG_SSR32( int32_t a, int8_t s){

18
libavcodec/h263.c
View File

@ -73,8 +73,6 @@ static void mpeg4_inv_pred_ac(MpegEncContext * s, DCTELEM *block, int n,
static void mpeg4_decode_sprite_trajectory(MpegEncContext * s);
static inline int ff_mpeg4_pred_dc(MpegEncContext * s, int n, uint16_t **dc_val_ptr, int *dir_ptr);
extern uint32_t inverse[256];
#ifdef CONFIG_ENCODERS
static uint8_t uni_DCtab_lum_len[512];
static uint8_t uni_DCtab_chrom_len[512];
@ -1823,7 +1821,6 @@ static inline int ff_mpeg4_pred_dc(MpegEncContext * s, int n, uint16_t **dc_val_
{
int a, b, c, wrap, pred, scale;
uint16_t *dc_val;
int dummy;
/* find prediction */
if (n < 4) {
@ -1859,16 +1856,7 @@ static inline int ff_mpeg4_pred_dc(MpegEncContext * s, int n, uint16_t **dc_val_
*dir_ptr = 0; /* left */
}
/* we assume pred is positive */
#ifdef ARCH_X86
asm volatile (
"xorl %%edx, %%edx \n\t"
"mul %%ecx \n\t"
: "=d" (pred), "=a"(dummy)
: "a" (pred + (scale >> 1)), "c" (inverse[scale])
);
#else
pred = (pred + (scale >> 1)) / scale;
#endif
pred = FASTDIV((pred + (scale >> 1)), scale);
/* prepare address for prediction update */
*dc_val_ptr = &dc_val[0];
@ -3668,8 +3656,8 @@ static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
/* DC coef */
if(s->partitioned_frame){
level = s->dc_val[0][ s->block_index[n] ];
if(n<4) level= (level + (s->y_dc_scale>>1))/s->y_dc_scale; //FIXME optimizs
else level= (level + (s->c_dc_scale>>1))/s->c_dc_scale;
if(n<4) level= FASTDIV((level + (s->y_dc_scale>>1)), s->y_dc_scale);
else level= FASTDIV((level + (s->c_dc_scale>>1)), s->c_dc_scale);
dc_pred_dir= (s->pred_dir_table[s->mb_x + s->mb_y*s->mb_stride]<<n)&32;
}else{
level = mpeg4_decode_dc(s, n, &dc_pred_dir);

1
libavcodec/i386/mpegvideo_mmx.c
View File

@ -26,7 +26,6 @@
extern uint8_t zigzag_direct_noperm[64];
extern uint16_t inv_zigzag_direct16[64];
extern uint32_t inverse[256];
static const unsigned long long int mm_wabs __attribute__ ((aligned(8))) = 0xffffffffffffffffULL;
static const unsigned long long int mm_wone __attribute__ ((aligned(8))) = 0x0001000100010001ULL;

10
libavcodec/msmpeg4.c
View File

@ -78,8 +78,6 @@ static int msmpeg4v12_decode_mb(MpegEncContext *s, DCTELEM block[6][64]);
static int msmpeg4v34_decode_mb(MpegEncContext *s, DCTELEM block[6][64]);
static int wmv2_decode_mb(MpegEncContext *s, DCTELEM block[6][64]);
extern uint32_t inverse[256];
#ifdef DEBUG
int intra_count = 0;
@ -699,7 +697,7 @@ static int get_dc(uint8_t *src, int stride, int scale)
sum+=src[x + y*stride];
}
}
return (sum + (scale>>1))/scale;
return FASTDIV((sum + (scale>>1)), scale);
}
/* dir = 0: left, dir = 1: top prediction */
@ -763,9 +761,9 @@ static inline int msmpeg4_pred_dc(MpegEncContext * s, int n,
b = (b + (8 >> 1)) / 8;
c = (c + (8 >> 1)) / 8;
} else {
a = (a + (scale >> 1)) / scale;
b = (b + (scale >> 1)) / scale;
c = (c + (scale >> 1)) / scale;
a = FASTDIV((a + (scale >> 1)), scale);
b = FASTDIV((b + (scale >> 1)), scale);
c = FASTDIV((c + (scale >> 1)), scale);
}
#endif
/* XXX: WARNING: they did not choose the same test as MPEG4. This