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avcodec/vc1_pred: Fix undefined shifts

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Found-by: Clang -fsanitize=shift
Reported-by: Thierry Foucu <tfoucu@google.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2015-03-17 01:51:59 +01:00
parent b17620b81b
commit d24af7044d
1 changed files with 9 additions and 7 deletions
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16
libavcodec/vc1_pred.c
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@ -170,9 +170,9 @@ static av_always_inline int scaleforsame(VC1Context *v, int i, int n /* MV */,
n >>= hpel;
if (v->s.pict_type != AV_PICTURE_TYPE_B || v->second_field || !dir) {
if (dim)
n = scaleforsame_y(v, i, n, dir) << hpel;
n = scaleforsame_y(v, i, n, dir) * (1 << hpel);
else
n = scaleforsame_x(v, n, dir) << hpel;
n = scaleforsame_x(v, n, dir) * (1 << hpel);
return n;
}
brfd = FFMIN(v->brfd, 3);
@ -202,7 +202,7 @@ static av_always_inline int scaleforopp(VC1Context *v, int n /* MV */,
refdist = dir ? v->brfd : v->frfd;
scaleopp = ff_vc1_field_mvpred_scales[dir ^ v->second_field][0][refdist];
n = (n * scaleopp >> 8) << hpel;
n = (n * scaleopp >> 8) * (1 << hpel);
return n;
}
@ -697,10 +697,12 @@ void ff_vc1_pred_b_mv(VC1Context *v, int dmv_x[2], int dmv_y[2],
r_x = v->range_x;
r_y = v->range_y;
/* scale MV difference to be quad-pel */
dmv_x[0] <<= 1 - s->quarter_sample;
dmv_y[0] <<= 1 - s->quarter_sample;
dmv_x[1] <<= 1 - s->quarter_sample;
dmv_y[1] <<= 1 - s->quarter_sample;
if (!s->quarter_sample) {
dmv_x[0] *= 2;
dmv_y[0] *= 2;
dmv_x[1] *= 2;
dmv_y[1] *= 2;
}
wrap = s->b8_stride;
xy = s->block_index[0];