diff options
| author | Ganesh Ajjanagadde <gajjanagadde@gmail.com> | 2015-10-09 14:43:04 -0400 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2015-10-09 23:01:55 +0200 |
| commit | 3be27e07d3c5239f6d53b86aebcd201f722df4d0 (patch) | |
| tree | 437ffba8a500225c4d146984b31189ee8abb0ff2 /libavcodec | |
| parent | 25d3013e36152635ca992b63469f6d5b890aaa83 (diff) | |
avcodec/mpegvideoenc: fix undefined negative left shift
This should fix the first undefined behavior reported in:
https://trac.ffmpeg.org/ticket/4727.
I can't reproduce the runtime behavior reported in the ticket, hence I
can't confirm that this actually fixes the exact issue reported in the
ticket.
Regardless, I can confirm that this is a genuine issue, and that
negative shifts can (and do) occur, fixed by this.
Tested with FATE.
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/mpegvideo_enc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/libavcodec/mpegvideo_enc.c b/libavcodec/mpegvideo_enc.c index 8e565c12a7..a6af8bda24 100644 --- a/libavcodec/mpegvideo_enc.c +++ b/libavcodec/mpegvideo_enc.c @@ -148,7 +148,7 @@ void ff_convert_matrix(MpegEncContext *s, int (*qmat)[64], qmat16[qscale][0][i] == 128 * 256) qmat16[qscale][0][i] = 128 * 256 - 1; qmat16[qscale][1][i] = - ROUNDED_DIV(bias << (16 - QUANT_BIAS_SHIFT), + ROUNDED_DIV(bias * (1<<(16 - QUANT_BIAS_SHIFT)), qmat16[qscale][0][i]); } } |