API changes, most recent first:
+2017-03-xx - xxxxxxx - lavc 57.85.101 - avcodec.h
+ vdpau hardware accelerated decoding now supports the new hwaccel API, which
+ can create the decoder context and allocate hardware frame automatically.
+ See AVCodecContext.hw_device_ctx and AVCodecContext.hw_frames_ctx.
+
+2017-03-xx - xxxxxxx - lavc 57.85.100 - avcodec.h
+ Add AVCodecContext.hwaccel_flags field. This will control some hwaccels at
+ a later point.
+
+2017-03-21 - xxxxxxx - lavf 57.67.100 / 57.08.0 - avio.h
+ Add AVIO_SEEKABLE_TIME flag.
+
+2017-03-21 - xxxxxxx - lavf 57.66.105, lavc 57.83.101 - avformat.h, avcodec.h
+ Deprecate AVFMT_FLAG_KEEP_SIDE_DATA. It will be ignored after the next major
+ bump, and libavformat will behave as if it were always set.
+ Deprecate av_packet_merge_side_data() and av_packet_split_side_data().
+
+2016-03-20 - xxxxxxx - lavu 55.50.100 / 55.21.0 - imgutils.h
+ Add av_image_copy_uc_from(), a version of av_image_copy() for copying
+ from GPU mapped memory.
+
2017-03-20 - 9c2436e - lavu 55.49.100 - pixdesc.h
Add AV_PIX_FMT_FLAG_BAYER pixel format flag.