[FFmpeg-cvslog] movenc: fixes a questionable valgrind uninitialized value warning

[Janne Grunau]

ffmpeg | branch: master | Janne Grunau <janne-libav at jannau.net> | Tue Jun  9 12:27:47 2015 +0200| [529c05698e88b057f0bea61e0d85f2b42925b5ea] | committer: Janne Grunau

movenc: fixes a questionable valgrind uninitialized value warning

display_matrix_size is only initialized when av_stream_get_side_data()
returns a side data pointer. The code is safe since the only effect this
has is setting the display_matrix pointer to NULL which it was already
anyway.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=529c05698e88b057f0bea61e0d85f2b42925b5ea
---

 libavformat/movenc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 30d397a..761c3e8 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -1518,7 +1518,7 @@ static int mov_write_tkhd_tag(AVIOContext *pb, MOVMuxContext *mov,
 
         display_matrix = (uint32_t*)av_stream_get_side_data(st, AV_PKT_DATA_DISPLAYMATRIX,
                                                             &display_matrix_size);
-        if (display_matrix_size < 9 * sizeof(*display_matrix))
+        if (display_matrix && display_matrix_size < 9 * sizeof(*display_matrix))
             display_matrix = NULL;
     }