API changes, most recent first:
+2021-04-27 - xxxxxxxxxx - lavf yyyyyyyyy - avformat.h
+ Constified the pointers to AVInputFormats and AVOutputFormats
+ in AVFormatContext, avformat_alloc_output_context2(),
+ av_find_input_format(), av_probe_input_format(),
+ av_probe_input_format2(), av_probe_input_format3(),
+ av_probe_input_buffer2(), av_probe_input_buffer(),
+ avformat_open_input(), av_guess_format() and av_guess_codec().
+ Furthermore, constified the AVProbeData in av_probe_input_format(),
+ av_probe_input_format2() and av_probe_input_format3().
+
+2021-04-19 - xxxxxxxxxx - lavu 56.74.100 - tx.h
+ Add AV_TX_FULL_IMDCT and AV_TX_UNALIGNED.
+
+2021-04-17 - xxxxxxxxxx - lavu 56.73.100 - frame.h detection_bbox.h
+ Add AV_FRAME_DATA_DETECTION_BBOXES
+
2021-04-06 - xxxxxxxxxx - lavf 58.78.100 - avformat.h
Add avformat_index_get_entries_count(), avformat_index_get_entry(),
and avformat_index_get_entry_from_timestamp().