Based off the srt encoder. The following features are unimplemented:

- fonts, colors, sizes
- alignment and positioning

The rest works well. For example, use ffmpeg to convert subtitles into the .vtt format:

  ffmpeg -i input.srt output.vtt
Signed-off-by: Aman Gupta <ffmpeg@tmm1.net>
Signed-off-by: Clément Bœsch <u@pkh.me>

This seems to be needed on some 32bit arches.

Use it instead of checking CODEC_FLAG_BITEXACT in the first stream's
codec context.

Using codec options inside lavf is fragile and can easily break when the
muxing codec context is not the encoding context.

Initial implementation by Andrew D'Addesio <modchipv12@gmail.com> during
GSoC 2012.

Completion by Anton Khirnov <anton@khirnov.net>, sponsored by the
Mozilla Corporation.

Further contributions by:
Christophe Gisquet <christophe.gisquet@gmail.com>
Janne Grunau <janne-libav@jannau.net>
Luca Barbato <lu_zero@gentoo.org>

With this the fate clients runtime cpu feature set should be visible
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Tested-by: Tim Nicholson <nichot20@yahoo.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

WMP doess not play the output files if the fields are
set to 0 and not overwritten (using pipe output).

Fixes ticket #3346.

fate/hevc: update with new sequences from jctvc(cherry picked from commit de6d9c586bd3852dfbe629a88ccc8c0f0a2bfcbb)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Partially undoes commit 2c4e08d8:

    riff: always generate a proper WAVEFORMATEX structure in
    ff_put_wav_header

A new flag, FF_PUT_WAV_HEADER_FORCE_WAVEFORMATEX, is added to force the
use of WAVEFORMATEX rather than PCMWAVEFORMAT even for PCM codecs.

This flag is used in the Matroska muxer (the cause of the original
change) and in the ASF muxer, because the specifications for
these formats indicate explicitly that WAVEFORMATEX should be used.

Muxers for other formats will return to the original behavior of writing
PCMWAVEFORMAT when writing a header for raw PCM.

In particular, this causes raw PCM in WAV to generate the canonical
44-byte header expected by some tools.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

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

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

This also tests LINEAR_CORE_FLT_SSE

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

Also set the RGBA pixel format correctly as the native endian format,
which is what it returns.

This fixes the tests on big endian.
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Peter Ross <pross@xvid.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This fixes rounding differences between platforms
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This should avoid slight differences in the output causes by input
size alignment differences between archs
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: Vittorio Giovara <vittorio.giovara@gmail.com>

This fixes the test on big endian.
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

This makes the output consistent on big-endian systems.

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

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

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

After this commit the created bitstream will be supported by future
decoders.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>