API changes, most recent first:
+2016-xx-xx - xxxxxxx
+ Change av_sha_update() and av_md5_sum()/av_md5_update() length
+ parameter type to size_t at next major bump.
+
+2016-xx-xx - xxxxxxx - lavc 57.29.0 - avcodec.h
+ Add AV_PKT_DATA_SPHERICAL packet side data to export AVSphericalMapping
+ information from containers.
+
+2016-xx-xx - xxxxxxx - lavu 55.30.0 - spherical.h
+ Add AV_FRAME_DATA_SPHERICAL value, av_spherical_alloc() API and
+ AVSphericalMapping type to export and describe spherical video properties.
+
+2016-xx-xx - xxxxxxx - lavf 57.10.0 - avformat.h
+ Add av_stream_add_side_data().
+
2016-xx-xx - xxxxxxx - lavu 55.28.0 - pixfmt.h
Add AV_PIX_FMT_GRAY12(LE/BE).
Deprecate struct vaapi_context and the vaapi.h installed header.
Callers should set AVCodecContext.hw_frames_ctx instead.
+------------------------------8<-------------------------------------
+ 12 branch was cut here
+----------------------------->8--------------------------------------
+
2016-07-20 - xxxxxxx - lavu 55.20.0 - cpu.h
Add AV_CPU_FLAG_SSSE3SLOW.