[FFmpeg-cvslog] ff_alloc_picture: free tables in case of dimension mismatches

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Mon Mar 11 21:29:14 2013 +0100| [ee3c3dd523623e0d9e69aa2ce268fef82b201458] | committer: Michael Niedermayer

ff_alloc_picture: free tables in case of dimension mismatches

Fixes memory corruption
In theory this should not be needed but its better to check at
one place than to hope 50 other places set the flags correctly

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ee3c3dd523623e0d9e69aa2ce268fef82b201458
---

 libavcodec/mpegvideo.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index 9fe93bf..d0c8262 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -411,6 +411,11 @@ int ff_alloc_picture(MpegEncContext *s, Picture *pic, int shared)
 {
     int i, ret;
 
+    if (pic->qscale_table_buf)
+        if (pic->mbskip_table_buf->size < s->mb_stride * s->mb_height + 2 ||
+            pic->qscale_table_buf->size < s->mb_stride * (s->mb_height + 1) + 1 + s->mb_stride)
+            free_picture_tables(pic);
+
     if (shared) {
         assert(pic->f.data[0]);
         pic->shared = 1;