When fix_sub_duration is used, and the duration fixing code is generating 0
duration, that is definitely zero, and not undefined or infinite (which may be
the case for decoded AVSubtitles depending on the codec), so it is safe to drop
it.

It fixes teletext subtitle sources, when the subtitles are transmitted twice
after each other for some reason.
Signed-off-by: Marton Balint <cus@passwd.hu>
Reviewed-by: Nicolas George <george@nsup.org>

Even if it does not matter at the moment, because subtitles with num_rect == 0
have no memory allocated, this is how we expect the users to use the API, a
returned AVSubtitle should be freed with avsubtitle_free.
Signed-off-by: Marton Balint <cus@passwd.hu>
Reviewed-by: Nicolas George <george@nsup.org>

It should not matter for real-life usage, it is just cleaner this way.
Signed-off-by: Marton Balint <cus@passwd.hu>
Reviewed-by: Nicolas George <george@nsup.org>

Launch option is defined in the Feed section.

Spotted-by: lazy ubitux

Should be redundant now that the option is documented.

The section shows only a limited use case, contains only redundant
information, and various mysterious mentions about things which don't
work correctly.

Mentioning build options, or bugs, or mysterious limitations should not
be done in the manual.

This is required to build with FFmpeg compilation options.

* qatar/master:
  h263dec: sanitize a condition.
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '4d388c0c':
  h264_refs: make sure not to write over the bounds of the default ref list

Conflicts:
	libavcodec/h264_refs.c

This condition should be impossible and was checked for by asserts.
the asserts are moved up in this merge to gurantee that no out of array
access can happen even if the state is "impossible".
Also if such impossible states could somehow be created, that should
be dealt with and not silently ignored.
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Timothy Gu <timothygu99@gmail.com>

While still incomplete, this is better than nothing at all.

This fixes unreasonable initial frame repeats
Fixes Ticket3176
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This reverts commit ca21116b.

Revert suggested by Jamal:
"Bad secondary effect i just noticed: Every time version.h is changed
 (git pull for example), anything that includes config.h will be
 recompiled. And that means pretty much every single file in the tree.
"

Avoid clash with version.h of the libraries.
Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Call ff_mpeg4_decode_picture_header() only when the decoder has the
MPEG4 codec id, not based on a vaguely related value of h263_pred.

Fixes invalid writes.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org

* qatar/master:
  doc/platform: Update to reflect current MSVC build situation

Conflicts:
	doc/platform.texi

See: ec0b0c2bMerged-by: Michael Niedermayer <michaelni@gmx.at>