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dehack *ps_state indexing in the branchless decoder

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Originally committed as revision 6683 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2006-10-13 14:21:25 +00:00
parent a991b1fecb
commit 68a205edef
2 changed files with 10 additions and 6 deletions
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11
libavcodec/cabac.c
View File

@ -50,6 +50,7 @@ static const uint8_t lps_range[64][4]= {
{ 6, 8, 9, 11}, { 6, 7, 9, 10}, { 6, 7, 8, 9}, { 2, 2, 2, 2},
};
uint8_t ff_h264_mlps_state[4*64];
uint8_t ff_h264_lps_range[2*65][4];
uint8_t ff_h264_lps_state[2*64];
uint8_t ff_h264_mps_state[2*64];
@ -132,16 +133,18 @@ void ff_init_cabac_states(CABACContext *c){
ff_h264_lps_range[2*i+1][j+4]= lps_range[i][j];
}
ff_h264_mlps_state[128+2*i+0]=
ff_h264_mps_state[2*i+0]= 2*mps_state[i]+0;
ff_h264_mlps_state[128+2*i+1]=
ff_h264_mps_state[2*i+1]= 2*mps_state[i]+1;
if( i ){
#ifdef BRANCHLESS_CABAC_DECODER
ff_h264_mps_state[-2*i-1]= 2*lps_state[i]+0; //FIXME yes this is not valid C but iam lazy, cleanup welcome
ff_h264_mps_state[-2*i-2]= 2*lps_state[i]+1;
ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0;
ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1;
}else{
ff_h264_mps_state[-2*i-1]= 1;
ff_h264_mps_state[-2*i-2]= 0;
ff_h264_mlps_state[128-2*i-1]= 1;
ff_h264_mlps_state[128-2*i-2]= 0;
#else
ff_h264_lps_state[2*i+0]= 2*lps_state[i]+0;
ff_h264_lps_state[2*i+1]= 2*lps_state[i]+1;

5
libavcodec/cabac.h
View File

@ -47,6 +47,7 @@ typedef struct CABACContext{
PutBitContext pb;
}CABACContext;
extern uint8_t ff_h264_mlps_state[4*64];
extern uint8_t ff_h264_lps_range[2*65][4]; ///< rangeTabLPS
extern uint8_t ff_h264_mps_state[2*64]; ///< transIdxMPS
extern uint8_t ff_h264_lps_state[2*64]; ///< transIdxLPS
@ -480,7 +481,7 @@ static int always_inline get_cabac_inline(CABACContext *c, uint8_t * const state
#endif /* CMOV_IS_FAST */
//eax:state ebx:low edx:mask esi:range
"movzbl "MANGLE(ff_h264_mps_state)"(%%eax), %%ecx \n\t"
"movzbl "MANGLE(ff_h264_mlps_state)"+128(%%eax), %%ecx \n\t"
"movb %%cl, (%1) \n\t"
"movl %%esi, %%edx \n\t"
@ -550,7 +551,7 @@ static int always_inline get_cabac_inline(CABACContext *c, uint8_t * const state
c->range += (RangeLPS - c->range) & lps_mask;
s^=lps_mask;
*state= ff_h264_mps_state[s];
*state= (ff_h264_mlps_state+128)[s];
bit= s&1;
lps_mask= ff_h264_norm_shift[c->range>>(CABAC_BITS+3)];