[Ffmpeg-cvslog] CVS: ffmpeg/libavcodec h264.c,1.156,1.157
Loren Merritt CVS
lorenm
Tue Sep 27 06:46:48 CEST 2005
Update of /cvsroot/ffmpeg/ffmpeg/libavcodec
In directory mail:/var2/tmp/cvs-serv23449
Modified Files:
h264.c
Log Message:
13% faster decode_residual (cavlc).
patch by diane_cartman at gmx dot de.
Index: h264.c
===================================================================
RCS file: /cvsroot/ffmpeg/ffmpeg/libavcodec/h264.c,v
retrieving revision 1.156
retrieving revision 1.157
diff -u -d -r1.156 -r1.157
--- h264.c 21 Sep 2005 08:14:17 -0000 1.156
+++ h264.c 27 Sep 2005 04:46:45 -0000 1.157
@@ -4437,8 +4437,8 @@
static int decode_residual(H264Context *h, GetBitContext *gb, DCTELEM *block, int n, const uint8_t *scantable, const uint16_t *qmul, int max_coeff){
MpegEncContext * const s = &h->s;
static const int coeff_token_table_index[17]= {0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3};
- int level[16], run[16];
- int suffix_length, zeros_left, coeff_num, coeff_token, total_coeff, i, trailing_ones;
+ int level[16];
+ int zeros_left, coeff_num, coeff_token, total_coeff, i, j, trailing_ones, run_before;
//FIXME put trailing_onex into the context
@@ -4471,12 +4471,12 @@
level[i]= 1 - 2*get_bits1(gb);
}
- suffix_length= total_coeff > 10 && trailing_ones < 3;
-
- for(; i<total_coeff; i++){
- const int prefix= get_level_prefix(gb);
+ if(i<total_coeff) {
int level_code, mask;
+ int suffix_length = total_coeff > 10 && trailing_ones < 3;
+ int prefix= get_level_prefix(gb);
+ //first coefficient has suffix_length equal to 0 or 1
if(prefix<14){ //FIXME try to build a large unified VLC table for all this
if(suffix_length)
level_code= (prefix<<suffix_length) + get_bits(gb, suffix_length); //part
@@ -4495,20 +4495,32 @@
return -1;
}
- if(i==trailing_ones && i<3) level_code+= 2; //FIXME split first iteration
+ if(trailing_ones < 3) level_code += 2;
+ suffix_length = 1;
+ if(level_code > 5)
+ suffix_length++;
mask= -(level_code&1);
level[i]= (((2+level_code)>>1) ^ mask) - mask;
+ i++;
- if(suffix_length==0) suffix_length=1; //FIXME split first iteration
-
-#if 1
- if(ABS(level[i]) > (3<<(suffix_length-1)) && suffix_length<6) suffix_length++;
-#else
- if((2+level_code)>>1) > (3<<(suffix_length-1)) && suffix_length<6) suffix_length++;
- /* ? == prefix > 2 or sth */
-#endif
- tprintf("level: %d suffix_length:%d\n", level[i], suffix_length);
+ //remaining coefficients have suffix_length > 0
+ for(;i<total_coeff;i++) {
+ static const int suffix_limit[7] = {0,5,11,23,47,95,INT_MAX };
+ prefix = get_level_prefix(gb);
+ if(prefix<15){
+ level_code = (prefix<<suffix_length) + get_bits(gb, suffix_length);
+ }else if(prefix==15){
+ level_code = (prefix<<suffix_length) + get_bits(gb, 12);
+ }else{
+ av_log(h->s.avctx, AV_LOG_ERROR, "prefix too large at %d %d\n", s->mb_x, s->mb_y);
+ return -1;
+ }
+ mask= -(level_code&1);
+ level[i]= (((2+level_code)>>1) ^ mask) - mask;
+ if(level_code > suffix_limit[suffix_length])
+ suffix_length++;
+ }
}
if(total_coeff == max_coeff)
@@ -4519,50 +4531,49 @@
else
zeros_left= get_vlc2(gb, total_zeros_vlc[ total_coeff-1 ].table, TOTAL_ZEROS_VLC_BITS, 1);
}
-
- for(i=0; i<total_coeff-1; i++){
- if(zeros_left <=0)
- break;
- else if(zeros_left < 7){
- run[i]= get_vlc2(gb, run_vlc[zeros_left-1].table, RUN_VLC_BITS, 1);
- }else{
- run[i]= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2);
- }
- zeros_left -= run[i];
- }
-
- if(zeros_left<0){
- av_log(h->s.avctx, AV_LOG_ERROR, "negative number of zero coeffs at %d %d\n", s->mb_x, s->mb_y);
- return -1;
- }
-
- for(; i<total_coeff-1; i++){
- run[i]= 0;
- }
-
- run[i]= zeros_left;
- coeff_num=-1;
+ coeff_num = zeros_left + total_coeff - 1;
+ j = scantable[coeff_num];
if(n > 24){
- for(i=total_coeff-1; i>=0; i--){ //FIXME merge into rundecode?
- int j;
-
- coeff_num += run[i] + 1; //FIXME add 1 earlier ?
+ block[j] = level[0];
+ for(i=1;i<total_coeff;i++) {
+ if(zeros_left <= 0)
+ run_before = 0;
+ else if(zeros_left < 7){
+ run_before= get_vlc2(gb, run_vlc[zeros_left-1].table, RUN_VLC_BITS, 1);
+ }else{
+ run_before= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2);
+ }
+ zeros_left -= run_before;
+ coeff_num -= 1 + run_before;
j= scantable[ coeff_num ];
block[j]= level[i];
}
}else{
- for(i=total_coeff-1; i>=0; i--){ //FIXME merge into rundecode?
- int j;
-
- coeff_num += run[i] + 1; //FIXME add 1 earlier ?
+ block[j] = level[0] * qmul[j];
+ for(i=1;i<total_coeff;i++) {
+ if(zeros_left <= 0)
+ run_before = 0;
+ else if(zeros_left < 7){
+ run_before= get_vlc2(gb, run_vlc[zeros_left-1].table, RUN_VLC_BITS, 1);
+ }else{
+ run_before= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2);
+ }
+ zeros_left -= run_before;
+ coeff_num -= 1 + run_before;
j= scantable[ coeff_num ];
block[j]= level[i] * qmul[j];
// printf("%d %d ", block[j], qmul[j]);
}
}
+
+ if(zeros_left<0){
+ av_log(h->s.avctx, AV_LOG_ERROR, "negative number of zero coeffs at %d %d\n", s->mb_x, s->mb_y);
+ return -1;
+ }
+
return 0;
}
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