[FFmpeg-devel] [HACK] fix issue 944

[Reimar Döffinger]

Hello,
the file in issue 944 causes mb_xy to become something around -300 and
then crashes.
Attached patch fixes this the brute-force way, for a better fix I'd need
hints where to look.
-------------- next part --------------
Index: libavcodec/h264.c
===================================================================
--- libavcodec/h264.c	(revision 18407)
+++ libavcodec/h264.c	(working copy)
@@ -1005,6 +1005,7 @@
         }else if(!(s->picture_structure & h->ref_list[1][0].reference) && !h->ref_list[1][0].mbaff){// FL -> FL & differ parity
             int fieldoff= 2*(h->ref_list[1][0].reference)-3;
             mb_xy += s->mb_stride*fieldoff;
+            mb_xy = FFMAX(mb_xy, 0);
         }
         goto single_col;
     }else{                                               // AFL/AFR/FR/FL -> AFR/FR