generic-library/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

(commit by michael)

Browse Source 
quantizer range bugfix (mpeg1 & mpeg4 encoding)

Originally committed as revision 277 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2002-01-24 14:34:03 +00:00
parent fd2848053f
commit 4e3269e87f
1 changed files with 38 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
libavcodec/mpegvideo.c
View File

@ -1066,6 +1066,21 @@ static int dct_quantize(MpegEncContext *s,
{ {
int i, j, level, last_non_zero, q; int i, j, level, last_non_zero, q;
const int *qmat; const int *qmat;
int minLevel, maxLevel;
if(s->avctx!=NULL && s->avctx->codec->id==CODEC_ID_MPEG4){
/* mpeg4 */
minLevel= -2048;
maxLevel= 2047;
}else if(s->out_format==FMT_MPEG1){
/* mpeg1 */
minLevel= -255;
maxLevel= 255;
}else{
/* h263 / msmpeg4 */
minLevel= -128;
maxLevel= 127;
}
av_fdct (block); av_fdct (block);
@ -1138,10 +1153,10 @@ static int dct_quantize(MpegEncContext *s,
h263: -128..127 h263: -128..127
mpeg4: -2048..2047 mpeg4: -2048..2047
*/ */
if (level > 127) if (level > maxLevel)
level = 127; level = maxLevel;
else if (level < -128) else if (level < minLevel)
level = -128; level = minLevel;
block[j] = level; block[j] = level;
last_non_zero = i; last_non_zero = i;
} else { } else {
@ -1157,6 +1172,21 @@ static int dct_quantize_mmx(MpegEncContext *s,
{ {
int i, j, level, last_non_zero, q; int i, j, level, last_non_zero, q;
const int *qmat; const int *qmat;
int minLevel, maxLevel;
if(s->avctx!=NULL && s->avctx->codec->id==CODEC_ID_MPEG4){
/* mpeg4 */
minLevel= -2048;
maxLevel= 2047;
}else if(s->out_format==FMT_MPEG1){
/* mpeg1 */
minLevel= -255;
maxLevel= 255;
}else{
/* h263 / msmpeg4 */
minLevel= -128;
maxLevel= 127;
}
av_fdct (block); av_fdct (block);
@ -1202,10 +1232,10 @@ static int dct_quantize_mmx(MpegEncContext *s,
h263: -128..127 h263: -128..127
mpeg4: -2048..2047 mpeg4: -2048..2047
*/ */
if (level > 127) if (level > maxLevel)
level = 127; level = maxLevel;
else if (level < -128) else if (level < minLevel)
level = -128; level = minLevel;
block[j] = level; block[j] = level;
last_non_zero = i; last_non_zero = i;
} else { } else {