API changes, most recent first:
+2018-01-xx - xxxxxxx - lavfi 7.11.101 - avfilter.h
+ Deprecate avfilter_link_get_channels(). Use av_buffersink_get_channels().
+
2017-xx-xx - xxxxxxx - lavr 4.0.0 - avresample.h
Deprecate the entire library. Merged years ago to provide compatibility
with Libav, it remained unmaintained by the FFmpeg project and duplicated