[FFmpeg-cvslog] imgconvert: avoid undefined left shift in avcodec_find_best_pix_fmt

[Janne Grunau]

ffmpeg | branch: release/0.10 | Janne Grunau <janne-libav at jannau.net> | Mon Jul  2 10:46:39 2012 +0200| [7a7229b52d1900279041991fadbd29b27e8dfe95] | committer: Anton Khirnov

imgconvert: avoid undefined left shift in avcodec_find_best_pix_fmt

CC: libav-stable at libav.org
(cherry picked from commit 39bb27bf79bc4c2d8beaed637a14176264cb1916)

Signed-off-by: Anton Khirnov <anton at khirnov.net>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7a7229b52d1900279041991fadbd29b27e8dfe95
---

 libavcodec/imgconvert.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavcodec/imgconvert.c b/libavcodec/imgconvert.c
index eab051b..1dfe3b7 100644
--- a/libavcodec/imgconvert.c
+++ b/libavcodec/imgconvert.c
@@ -612,7 +612,8 @@ static enum PixelFormat avcodec_find_best_pix_fmt1(int64_t pix_fmt_mask,
     /* find exact color match with smallest size */
     dst_pix_fmt = PIX_FMT_NONE;
     min_dist = 0x7fffffff;
-    for(i = 0;i < PIX_FMT_NB; i++) {
+    /* test only the first 64 pixel formats to avoid undefined behaviour */
+    for (i = 0; i < 64; i++) {
         if (pix_fmt_mask & (1ULL << i)) {
             loss = avcodec_get_pix_fmt_loss(i, src_pix_fmt, has_alpha) & loss_mask;
             if (loss == 0) {