Find a bug on http://ffmpeg.org/trac/ffmpeg , download the lastest ffmpeg from  git://source.ffmpeg.org/ffmpeg.git , fix the bug and submit a patch to our mailing list at https://lists.ffmpeg.org/mailman/listinfo/ffmpeg-devel/

Once the patch passed review, your task will be closed.

Note, this task requires good knowledge of git, gdb and C. And you are expected to work on your own, our goal is to fix a bug with your help in less time than it would take us to fix the bug ourselfs.