[FFmpeg-cvslog] mtv: Fix FPE with 0 dimensions.

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Thu Dec 15 00:26:14 2011 +0100| [8b9b6332dfeb169098c8ab1351d66fc5b474dd55] | committer: Michael Niedermayer

mtv: Fix FPE with 0 dimensions.
Fixes Ticket755
Bug Found by: Diana Elena Muscalu

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8b9b6332dfeb169098c8ab1351d66fc5b474dd55
---

 libavformat/mtv.c |   14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/libavformat/mtv.c b/libavformat/mtv.c
index 00da9a1..b31e4cb 100644
--- a/libavformat/mtv.c
+++ b/libavformat/mtv.c
@@ -96,16 +96,26 @@ static int mtv_read_header(AVFormatContext *s, AVFormatParameters *ap)
 
     /* Calculate width and height if missing from header */
 
-    if(!mtv->img_width)
+    if(mtv->img_bpp>>3){
+    if(!mtv->img_width && mtv->img_height)
         mtv->img_width=mtv->img_segment_size / (mtv->img_bpp>>3)
                         / mtv->img_height;
 
-    if(!mtv->img_height)
+    if(!mtv->img_height && mtv->img_width)
         mtv->img_height=mtv->img_segment_size / (mtv->img_bpp>>3)
                         / mtv->img_width;
+    }
+    if(!mtv->img_height || !mtv->img_width){
+        av_log(s, AV_LOG_ERROR, "width or height is invalid and I cannot calculate them from other information\n");
+        return AVERROR(EINVAL);
+    }
 
     avio_skip(pb, 4);
     audio_subsegments = avio_rl16(pb);
+    if(!audio_subsegments){
+        av_log(s, AV_LOG_ERROR, "audio_subsegments is 0\n");
+        return AVERROR(EINVAL);
+    }
     mtv->full_segment_size =
         audio_subsegments * (MTV_AUDIO_PADDING_SIZE + MTV_ASUBCHUNK_DATA_SIZE) +
         mtv->img_segment_size;