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ffmpeg.wasm-core
Commit 4e3269e8 authored by Michael Niedermayer's avatar Michael Niedermayer
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(commit by michael) 

quantizer range bugfix (mpeg1 & mpeg4 encoding)

Originally committed as revision 277 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent fd284805
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Showing with 38 additions and 8 deletions
libavcodec/mpegvideo.c
View file @ 4e3269e8
......@@ -1066,6 +1066,21 @@ static int dct_quantize(MpegEncContext *s,
{
int i, j, level, last_non_zero, q;
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);
......@@ -1138,10 +1153,10 @@ static int dct_quantize(MpegEncContext *s,
h263: -128..127
mpeg4: -2048..2047
*/
if (level > 127)
level = 127;
else if (level < -128)
level = -128;
if (level > maxLevel)
level = maxLevel;
else if (level < minLevel)
level = minLevel;
block[j] = level;
last_non_zero = i;
} else {
......@@ -1157,6 +1172,21 @@ static int dct_quantize_mmx(MpegEncContext *s,
{
int i, j, level, last_non_zero, q;
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);
......@@ -1202,10 +1232,10 @@ static int dct_quantize_mmx(MpegEncContext *s,
h263: -128..127
mpeg4: -2048..2047
*/
if (level > 127)
level = 127;
else if (level < -128)
level = -128;
if (level > maxLevel)
level = maxLevel;
else if (level < minLevel)
level = minLevel;
block[j] = level;
last_non_zero = i;
} else {
......
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