API changes, most recent first:
+2021-03-19 - xxxxxxxxxx - lavf 58.75.100 - avformat.h
+ AVChapter.id will be changed from int to int64_t
+ on the next major version bump.
+
2021-03-xx - xxxxxxxxxx - lavc 58.133.100 - codec.h
Deprecated av_init_packet(). Once removed, sizeof(AVPacket) will
no longer be a part of the public ABI.