API changes, most recent first:
-2012-12-20 - xxxxxxx - lavfi 3.28.100 - avfilter.h
+2013-01-17 - a1a707f - lavf 54.61.100
+ Add av_codec_get_tag2().
+
+2012-12-20 - 34de47aa - lavfi 3.29.100 - avfilter.h
Add AVFilterLink.channels, avfilter_link_get_channels()
and avfilter_ref_get_channels().
2012-03-26 - a67d9cf - lavfi 2.66.100
Add avfilter_fill_frame_from_{audio_,}buffer_ref() functions.
+2013-01-xx - xxxxxxx - lavu 52.5.0 - hmac.h
+ Add AVHMAC.
+
2013-01-13 - xxxxxxx - lavc 54.36.0 - vdpau.h
Add AVVDPAUContext struct for VDPAU hardware-accelerated decoding.