API changes, most recent first:
+2021-03-12 - xxxxxxxxxx - lavc 58.131.100 - avcodec.h codec.h
+ Add a get_encode_buffer callback to AVCodecContext, similar to
+ get_buffer2 but for encoders.
+ Add avcodec_default_get_encode_buffer().
+ Add AV_GET_ENCODE_BUFFER_FLAG_REF.
+ Encoders may now be flagged as AV_CODEC_CAP_DR1 capable.
+
+2021-03-10 - xxxxxxxxxx - lavf 58.72.100 - avformat.h
+ Change AVBufferRef related AVStream function and struct size
+ parameter and fields type to size_t at next major bump.
+
+2021-03-10 - xxxxxxxxxx - lavc 58.130.100 - packet.h
+ Change AVBufferRef related AVPacket function and struct size
+ parameter and fields type to size_t at next major bump.
+
+2021-03-10 - xxxxxxxxxx - lavu 56.68.100 - buffer.h frame.h
+ Change AVBufferRef and relevant AVFrame function and struct size
+ parameter and fields type to size_t at next major bump.
+
+2021-03-04 - xxxxxxxxxx - lavc 58.128.101 - avcodec.h
+ Enable err_recognition to be set for encoders.
+
+2021-03-03 - xxxxxxxxxx - lavf 58.70.100 - avformat.h
+ Deprecate AVFMT_FLAG_PRIV_OPT. It will do nothing
+ as soon as av_demuxer_open() is removed.
+
+2021-02-27 - xxxxxxxxxx - lavc 58.126.100 - avcodec.h
+ Deprecated avcodec_get_frame_class().
+
+2021-02-21 - xxxxxxxxxx - lavu 56.66.100 - tx.h
+ Add enum AVTXFlags and AVTXFlags.AV_TX_INPLACE
+
+2021-02-14 - xxxxxxxxxx - lavd 58.12.100 - avdevice.h
+ Deprecated avdevice_capabilities_create() and
+ avdevice_capabilities_free().
+
+2021-02-xx - xxxxxxxxxx - lavu 56.xx.100 - common.h
+ Add FFABS64U()
+
2021-01-26 - xxxxxxxxxx - lavu 56.64.100 - common.h
Add FFABSU()