API changes, most recent first:
+2016-xx-xx - xxxxxxx - lavc 57.37.100 - avcodec.h
+ Add a new audio/video encoding and decoding API with decoupled input
+ and output -- avcodec_send_packet(), avcodec_receive_frame(),
+ avcodec_send_frame() and avcodec_receive_packet().
+
2016-xx-xx - xxxxxxx - lavc 57.15.0 - avcodec.h
Add a new bitstream filtering API working with AVPackets.
Deprecate the old bistream filtering API.