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s->c_dc_scale was 7 if s->qscale==2 but should be 8 (the bug is visible in deep red areas in high bitrate clips) - patch by Michael Niedermayer <michaelni@gmx.at>

Originally committed as revision 255 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2002-01-11 21:27:04 +00:00 committed by Arpi
parent 477c35a9f0
commit 6fb904ce30

View File

@ -347,16 +347,35 @@ void msmpeg4_encode_mb(MpegEncContext * s,
/* strongly inspirated from MPEG4, but not exactly the same ! */
void msmpeg4_dc_scale(MpegEncContext * s)
{
int scale;
if (s->qscale < 5)
scale = 8;
else if (s->qscale < 9)
scale = 2 * s->qscale;
else
scale = s->qscale + 8;
s->y_dc_scale = scale;
s->c_dc_scale = (s->qscale + 13) / 2;
if (s->qscale < 5){
s->y_dc_scale = 8;
s->c_dc_scale = 8;
// s->c_dc_scale = (s->qscale + 13)>>1;
}else if (s->qscale < 9){
s->y_dc_scale = 2 * s->qscale;
s->c_dc_scale = (s->qscale + 13)>>1;
}else{
s->y_dc_scale = s->qscale + 8;
s->c_dc_scale = (s->qscale + 13)>>1;
}
// this differs for quant >24 from mpeg4
// if(s->qscale==13) s->c_dc_scale=14;
// if(s->qscale>=6)
// printf("%d", s->qscale);
/* s->c_dc_scale values (found by Michael Nidermayer)
qscale=2 -> 8 (yes iam sure about that)
qscale=3 -> 8
qscale=4 -> 8
qscale=5 -> 9
qscale=6 -> 9
qscale=7 -> 10
qscale=8 -> 10
qscale=9 -> 11
qscale=10-> 11
*/
}
/* dir = 0: left, dir = 1: top prediction */