API changes, most recent first:
+2015-xx-xx - xxxxxxx - lavc 57.5.0 - avcodec.h
+ Add data and linesize array to AVSubtitleRect, to be used instead of
+ the ones from the embedded AVPicture.
+
2015-xx-xx - xxxxxxx - lavc 57.0.0 - qsv.h
Add an API for allocating opaque surfaces.