API changes, most recent first:
+2015-xx-xx - xxxxxxx - lavc 57.0.0 - avcodec.h
+ Change type of AVPacket.duration from int to int64_t.
+
2015-xx-xx - xxxxxxx - lavc 57.2.0 - d3d11va.h
Add av_d3d11va_alloc_context(). This function must from now on be used for
allocating AVD3D11VAContext.