Log Message:
Update to 2.4.1:

The FFmpeg Project proudly presents FFmpeg 2.4 "Fresnel", just 2 months
after the release of 2.3. Since this wasn't a long time ago, the Changelog
is a bit short this time.

The most important thing in this release is the major version bump of the
libraries.  This means that this release is neither ABI-compatible nor
fully API-compatible. But on the other hand it is aligned with the Libav
11 release series, and will as a result probably end up being maintained for
a long time.

Important API changes since 2.3:

• The new field mime_type was added to AVProbeData, which can
  cause crashes, if it is not initialized.
• Some deprecated functions were removed.
• The avfilter_graph_parse function was made compatible with Libav.
• The Matroska demuxer now outputs verbatim ASS packets.

Please refer to the doc/APIchanges file for more information.

libavformat

• Icecast protocol.
• API for live metadata updates through event flags.
• UTF-16 support in text subtitles formats.
• The ASS muxer now reorders the Dialogue events properly.
• support for H.261 RTP payload format (RFC 4587)
• HEVC/H.265 RTP payload format (draft v6) depacketizer

libavfilter

• Ported lenscorrection filter from frei0r filter.
• Large optimizations in dctdnoiz to make it usable.
• Added codecview filter to visualize information exported by some codecs.
• Added silenceremove filter.

libavutil

• Added clip() function in eval.

Behaviour changes

• dctdnoiz filter now uses a block size of 8x8 instead of 16x16 by default
• -vismv option is deprecated in favor of the codecview filter
• libmodplug is now detected through pkg-config
• HTML documentation generation through texi2html is deprecated in
  favor of makeinfo/texi2any
• ICY metadata are now requested by default with the HTTP protocol