[FFmpeg-cvslog] error_concealment: Check that the reference is not NULL

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Thu Apr 19 12:14:08 2012 +0200| [903ccf71b757cd30ce8e2378fd8ba87664e78449] | committer: Michael Niedermayer

error_concealment: Check that the reference is not NULL

In normal picture decoding this does not need to be checked but as
error concealment is run in the case of errors the availability of
references is less certain. This may be fixed differently at some
point so that all references are always filled in before the EC
code, in which case this should then be changed to an assert()

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=903ccf71b757cd30ce8e2378fd8ba87664e78449
---

 libavcodec/error_resilience.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/libavcodec/error_resilience.c b/libavcodec/error_resilience.c
index 15c5b39..2691109 100644
--- a/libavcodec/error_resilience.c
+++ b/libavcodec/error_resilience.c
@@ -60,6 +60,10 @@ static void decode_mb(MpegEncContext *s, int ref)
          * practice then correct remapping should be added. */
         if (ref >= h->ref_count[0])
             ref = 0;
+        if (!h->ref_list[0][ref].f.data[0]) {
+            av_log(s->avctx, AV_LOG_DEBUG, "Reference not available for error concealing\n");
+            ref = 0;
+        }
         fill_rectangle(&s->current_picture.f.ref_index[0][4 * h->mb_xy],
                        2, 2, 2, ref, 1);
         fill_rectangle(&h->ref_cache[0][scan8[0]], 4, 4, 8, ref, 1);