There are 4 separate WebVTT text track kinds: subtitles (the default
if not otherwise specified), captions, descriptions, and metadata.
The WebM muxer needs to know which WebVTT text track kind this is, in
order to synthesize the correct track type and codec id.

To allow a demuxer to indicate the text track kind of the input, a new
set of AV_DISPOSITION flag values has been added, corresponding to
each of the non-default text track kind values.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Fixes ticket #1910.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fixes Ticket2551
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fixes Ticket2537
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

* qatar/master:
  lavf: don't abort if both encoder and muxer aspect ratios are not set

Conflicts:
	libavformat/mux.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'c3e58f8f':
  matroskaenc: restore compatibility with non referenced AVPacket
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '95d52464':
  lavc: Add option to encode MPEG-2 AAC with libfdk-aac

Conflicts:
	doc/APIchanges
	libavcodec/version.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'ace87c19':
  configure: whitespace cosmetics

Conflicts:
	configure
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '6dc65986':
  configure: Simplify an expression with enabled_all.
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Fixes Ticket2532
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fixes Ticket2476
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This fixes occasional failures of vp8-test-vector-010 with frame-level
multithreading enabled.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

* qatar/master:
  configure: More msvc/icl combining
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'f963f701':
  ogg: relax demuxer conformance checks

Conflicts:
	libavformat/oggdec.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '42cc6cef':
  avconv: report the error for codec open failure
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '1e340af8':
  avconv: drop additional strerror fallback
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Avisynth is a non-unicode application and cannot accept UTF-8
characters. Therefore, the input filename should be converted to
the code page that it expects.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

As of r5799 in MinGW-w64's trunk, which is he upcoming major version 3,
the POSIX-compliant vsnprintf implementation is disabled by default.
Enable it for this version. Keep using out own implementation for
prior versions, because it is broken in them.

Relevant Reference Thread: http://article.gmane.org/gmane.comp.gnu.mingw.w64.general/7133Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Some samples in the wild are missing headers that are expected by the
specification but in practice do not affect decoding.

External codec may have corner case reason to fail at init, better
report them instead having the user wonder.

strerror_r is called by av_strerror already.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>