Fix warning:
libavfilter/vf_lut.c: In function ‘draw_slice’:
libavfilter/vf_lut.c:297:15: warning: unused variable ‘k’ [-Wunused-variable]

Also deprecate the use of numerical values.

This is useful for marking progressive video processed by the filter as
interlaced, avoiding the interlaced flag to switch back and forth at each
frame.

This new mode is useful for generating frames for interlaced video
displays. Typically interlaced video displays have no form of field
synchronisation. This new mode guarantees correct field order without
any requirement for field synchronisation.

Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

The call to the next filter_sample will likely unref the
current buffer, so it is not possible to read it afterwards.

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

Also add internal function ff_null_start_frame_keep_ref().

Fix crash when a following filter (e.g. settb) will unref the reference
passed by start_frame(), and then the reference is accessed in
end_frame() through inlink->cur_buf.

The old code had two bugs:

For audio filters, the format was not set.

For video filters, if several links reference the same format list,
the same format must be selected in the end. This is done by
setting formats->format_count to 1: the other links sharing
the reference will therefore have only one choice.
If the heuristic does not pick the first format, the selected format
must also be moved to the first position.

This is not an erroneous condition, do not print a warning.

Keep a heap of all sink links ordered by timestamps.

Fix warning:
libavfilter/vf_setfield.c: In function ‘init’:
libavfilter/vf_setfield.c:64:20: warning: too many arguments for format [-Wformat-extra-args]

The new name better reflects the meaning of the variable, after the
recent change.

Add "prog" parameter value, and deprecate numeric values.

Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

The native libavfilter hflip filter does the same thing.

Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

Tested-by: Robert Nagy <ronag89@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>

This fixes regressions caused by switching from ffmpegs system to avfilters.

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

Prevents it from referring to the rest of the list.

Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

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

The user submitted variable in this function is frame, not buf.

This is required for letting applications to create and destroy
AVFilterInOut structs in a convenient way.

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

Right now, e.g. scale,[in]overlay would connect scale to the first
overlay input and [in] to the second, which goes against the
documentation and is unintuitive.

The bug happens because of the ordering mess in curr_inputs variable:
1) the unlabeled links from the previous filter are added to it in
correct order
2) input labels are parsed and inserted to the beginning one by one
(i.e. in reverse order)
3) curr_inputs is matched against filter inputs in reverse order

Fix the problem by always using proper ordering without trying to be
clever.

Unlike avfilter_graph_parse(), it returns unlinked inputs and outputs
to the caller, which allows parsing of graphs where inputs/outputs are
not known in advance.

It was ported to a native libavfilter filter.

Partially based on the port by Niel van der Westhuizen
<nielkie@gmail.com>, done for GCI 2010. Same output as the original
filter and as fast.

See thread:
Subject: [FFmpeg-devel] [PATCH] Port MPlayer 2xSaI filter to libavfilter
Date: Thu, 25 Nov 2010 01:31:24 +1000

The header is part of the public API, in particular is used by
doc/examples/filtering_audio.c.

Fixes Ticket1184

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