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h261 dequant fix

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Originally committed as revision 3180 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2004-05-31 00:42:55 +00:00
parent b658ecfeb8
commit bb8140f29d
1 changed files with 9 additions and 9 deletions
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18
libavcodec/mpegvideo.c
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@ -5800,7 +5800,7 @@ static void dct_unquantize_h263_inter_c(MpegEncContext *s,
static void dct_unquantize_h261_intra_c(MpegEncContext *s,
DCTELEM *block, int n, int qscale)
{
int i, level, odd;
int i, level, even;
int nCoeffs;
assert(s->block_last_index[n]>=0);
@ -5809,16 +5809,16 @@ static void dct_unquantize_h261_intra_c(MpegEncContext *s,
block[0] = block[0] * s->y_dc_scale;
else
block[0] = block[0] * s->c_dc_scale;
odd = qscale & 0x1;
even = (qscale & 1)^1;
nCoeffs= s->inter_scantable.raster_end[ s->block_last_index[n] ];
for(i=1; i<=nCoeffs; i++){
level = block[i];
if (level){
if (level < 0){
level = qscale * ((level << 1) - 1) + (~odd);
level = qscale * ((level << 1) - 1) + even;
}else{
level = qscale * ((level << 1) + 1) - (~odd);
level = qscale * ((level << 1) + 1) - even;
}
}
block[i] = level;
@ -5828,12 +5828,12 @@ static void dct_unquantize_h261_intra_c(MpegEncContext *s,
static void dct_unquantize_h261_inter_c(MpegEncContext *s,
DCTELEM *block, int n, int qscale)
{
int i, level, odd;
int i, level, even;
int nCoeffs;
assert(s->block_last_index[n]>=0);
odd = qscale & 0x1;
even = (qscale & 1)^1;
nCoeffs= s->inter_scantable.raster_end[ s->block_last_index[n] ];
@ -5841,9 +5841,9 @@ static void dct_unquantize_h261_inter_c(MpegEncContext *s,
level = block[i];
if (level){
if (level < 0){
level = qscale * ((level << 1) - 1) + (~odd);
level = qscale * ((level << 1) - 1) + even;
}else{
level = qscale * ((level << 1) + 1) - (~odd);
level = qscale * ((level << 1) + 1) - even;
}
}
block[i] = level;