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ffmpeg
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fixing wmv1 bugs, it was foolish to belive that m$ would use the same dc prediction as mpeg4 just cuz they changed it a bit from msmpeg4v3 

Originally committed as revision 700 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2002-06-22 15:52:25 +00:00
parent 0d9f3d85f6
commit bd5e1c72f8
1 changed files with 46 additions and 20 deletions
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66
libavcodec/msmpeg4.c
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@ -21,7 +21,7 @@
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
//#define PRINT_MB
/*
* You can also call this codec : MPEG4 with a twist !
@ -674,13 +674,22 @@ static inline int msmpeg4_pred_dc(MpegEncContext * s, int n,
#endif
/* XXX: WARNING: they did not choose the same test as MPEG4. This
is very important ! */
if (abs(a - b) <= abs(b - c)) {
pred = c;
*dir_ptr = 1;
} else {
pred = a;
*dir_ptr = 0;
if(s->msmpeg4_version>3){
if (abs(a - b) < abs(b - c)) {
pred = c;
*dir_ptr = 1;
} else {
pred = a;
*dir_ptr = 0;
}
}else{
if (abs(a - b) <= abs(b - c)) {
pred = c;
*dir_ptr = 1;
} else {
pred = a;
*dir_ptr = 0;
}
}
/* update predictor */
@ -703,10 +712,7 @@ static void msmpeg4_encode_dc(MpegEncContext * s, int level, int n, int *dir_ptr
*dc_val= level;
}else{
UINT16 *dc_val;
if(s->msmpeg4_version<=3)
pred = msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
else
pred = ff_mpeg4_pred_dc(s, n, &dc_val, dir_ptr);
pred = msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
/* update predictor */
if (n < 4) {
@ -1374,6 +1380,12 @@ int msmpeg4_decode_mb(MpegEncContext *s,
int cbp, code, i;
UINT8 *coded_val;
#ifdef PRINT_MB
if(s->mb_x==0){
printf("\n");
if(s->mb_y==0) printf("\n");
}
#endif
/* special slice handling */
if (s->mb_x == 0) {
if (s->slice_height && (s->mb_y % s->slice_height) == 0) {
@ -1419,6 +1431,9 @@ int msmpeg4_decode_mb(MpegEncContext *s,
s->mv[0][0][0] = 0;
s->mv[0][0][1] = 0;
s->mb_skiped = 1;
#ifdef PRINT_MB
printf("S ");
#endif
return 0;
}
}
@ -1464,10 +1479,16 @@ int msmpeg4_decode_mb(MpegEncContext *s,
s->mv_type = MV_TYPE_16X16;
s->mv[0][0][0] = mx;
s->mv[0][0][1] = my;
#ifdef PRINT_MB
printf("P ");
#endif
} else {
//printf("I at %d %d %d %06X\n", s->mb_x, s->mb_y, ((cbp&3)? 1 : 0) +((cbp&0x3C)? 2 : 0), show_bits(&s->gb, 24));
set_stat(ST_INTRA_MB);
s->ac_pred = get_bits1(&s->gb);
#ifdef PRINT_MB
printf("%c", s->ac_pred ? 'A' : 'I');
#endif
if(s->per_mb_rl_table && cbp){
s->rl_table_index = decode012(&s->gb);
s->rl_chroma_table_index = s->rl_table_index;
@ -1481,7 +1502,7 @@ int msmpeg4_decode_mb(MpegEncContext *s,
return -1;
}
}
return 0;
}
@ -1501,20 +1522,28 @@ static inline int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
/* DC coef */
set_stat(ST_DC);
level = msmpeg4_decode_dc(s, n, &dc_pred_dir);
#ifdef PRINT_MB
{
static int c;
if(n==0) c=0;
if(n==4) printf("%X", c);
c+= c +dc_pred_dir;
}
#endif
if (level < 0){
fprintf(stderr, "dc overflow-\n");
fprintf(stderr, "dc overflow- block: %d qscale: %d//\n", n, s->qscale);
return -1;
}
if (n < 4) {
rl = &rl_table[s->rl_table_index];
if(level > 256*s->y_dc_scale){
fprintf(stderr, "dc overflow+\n");
fprintf(stderr, "dc overflow+ L qscale: %d//\n", s->qscale);
return -1;
}
} else {
rl = &rl_table[3 + s->rl_chroma_table_index];
if(level > 256*s->c_dc_scale){
fprintf(stderr, "dc overflow+\n");
fprintf(stderr, "dc overflow+ C qscale: %d//\n", s->qscale);
return -1;
}
}
@ -1730,10 +1759,7 @@ static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
*dc_val= level;
}else{
UINT16 *dc_val;
if(s->msmpeg4_version<=3)
pred = msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
else
pred = ff_mpeg4_pred_dc(s, n, &dc_val, dir_ptr);
pred = msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
level += pred;
/* update predictor */