Bug 1183

This point release includes some minor updates to make the 0.5 release series
usable for users that need to retain the existing behavior as closely as
possible. The changes follow below:

Security fixes
--------------

Various programming errors in container and codec implementations
may lead to denial of service or the execution of arbitrary code
if the user is tricked into opening a malformed media file or stream.

Affected and updated have been the implementations of the following
codecs and container formats:

 - the Vorbis audio codec
 - the FF Video 1 codec
 - the MPEG audio codec
 - the H264 video codec
 - the MLP codec
 - the HuffYUV codec
 - the ASF demuxer
 - the Ogg container implementation
 - the MOV container implementation

Symbol Versioning enabled
-------------------------

The backported symbol versioning change is enabled on platforms that support
it. This allows users to upgrade from 0.5.1 to the upcoming 0.6 release
without having to recompile their applications. Please note that distributors
have to recompile applications against 0.5.1 before upgrading to 0.6.

libx264.c backport
------------------

This release includes a backport to the libx264 wrapper that allows FFmpeg to
be compiled against newer versions of libx264 up to API version 85.

licensing changes
-----------------

Previously both libswscale and our AC-3 decoder had GPLed parts. These have
been replaced by fresh LGPL code. x86 optimizations for libswscale remain GPL,
but the C code is fully functional. Optimizations for other architectures have
been relicensed to LGPL.

AMR-NB decoding/encoding and AMR-WB decoding is now possible through the free
software OpenCORE libraries as an alternative to the non-free libamr libraries.

We found out that libfaac contains non-free parts and is not LGPL as previously
claimed. We have changed configure to reflect this. You now have to pass the
--enable-nonfree option if you wish to compile with libfaac support enabled.

Furthermore the non-free bits in libavcodec/fdctref.c have been rewritten. Note
well that they were only used in a test program and never compiled into any
FFmpeg library.


changelog: http://ffmpeg.org/releases/ffmpeg-0.5.1.changelog


-thanks-