avcodec/ituh263dec: Fix undefined left shift of negative number

Fixes ticket #8160.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavcodec/ituh263dec.c b/libavcodec/ituh263dec.c
index 1b57e53cad9ff934dde788562b61b9748e8e5d72..afc786bd8b2e55b42b25eed3a77fdb420b722567 100644 (file)
--- a/libavcodec/ituh263dec.c
+++ b/libavcodec/ituh263dec.c
@@ -1281,7 +1281,7 @@ int ff_h263_decode_picture_header(MpegEncContext *s)
         for(i=0; i<13; i++){
             for(j=0; j<3; j++){
                 int v= get_bits(&s->gb, 8);
-                v |= get_sbits(&s->gb, 8)<<8;
+                v |= get_sbits(&s->gb, 8) * (1 << 8);
                 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
             }
             av_log(s->avctx, AV_LOG_DEBUG, "\n");