API changes, most recent first:
+2016-04-27 - xxxxxxx - lavu 55.23.100 - log.h
+ Add a new function av_log_format_line2() which returns number of bytes
+ written to the target buffer.
+
+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 bitstream filtering API.
+
+2016-xx-xx - xxxxxxx - lavfi 6.42.0 - avfilter.h
+ Add AVFilterContext.hw_device_ctx.
+
+2016-xx-xx - xxxxxxx - lavu 55.22.0 - hwcontext_vaapi.h
+ Add new installed header with VAAPI-specific hwcontext definitions.
+
+2016-xx-xx - xxxxxxx - lavu 55.21.0 - hwcontext.h
+ Add AVHWFramesConstraints and associated API.
+
2016-04-11 - xxxxxxx - lavf 57.33.0 - avformat.h
Add AVStream.codecpar, deprecate AVStream.codec.