Some filters need several input frames before producing output.
For these filter, it becomes simpler to return 0 in
request_frame() and let the framework call it again until
output has been produced.

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

This avoids ABI issues

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

Deprecate AVFilterBuffer/AVFilterBufferRef and everything related to it
and use AVFrame instead.

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

The total number of implemented filters is already over 128.

Move the first use of `link' after the null pointer check.

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Reviewed-by: Stefano Sabatini <stefasab@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Unlike the original ff_start_frame code, the incoming reference
may be freed before that point.

Fix CID966654.

Reviewed-by: Nicolas George <nicolas.george@normalesup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

The sample rate and channel layout are negotiated and set
by the filter graph system.

Also: fix af_pan and af_aresample, that forgot to update
audio->channels.

With this we can mix filters using filter_frame OR start/draw_slice/end

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

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

Based on patch by Anton Khirnov
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Any alleged performance benefits gained from the split are purely
mythological and do not justify added code complexity.

Also reorder some other #include when applicable.

Signed-off-by: Mans Rullgard <mans@mansr.com>

In avfilter_config_links(), if the current channel layout is not
specified, set the same value of the previous link in the filterchain.

Consistent with the logic used to set the other link parameters.

Fix a memleak that the recent change of architecture made
more likely to happen.

It will help forward errors and maintain consistency.

Signed-off-by: Martin Storsjö <martin@martin.st>

Allow iteration over filter options.

libavfilter/avfilter.c:224:9: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 5 has type ‘int’ [-Wformat]

The doxy says, and the heap implementations assumes,
it is in AV_TIME_BASE units.

This will be used by filters which require an opaque field to be passed
in input. Should be required only for filters which imply a programmatic
use.

This is possibly a temporary solution, to be removed when we'll have a
clearer and better agreememnt of how/if to pass binary data for
initializing a filter.

See thread:
Subject: [FFmpeg-devel][PATCH] lavfi: add init2 callback
Date: Fri,  6 Jul 2012 01:22:17 +0200

Links can be set up to group samples into buffers of
specified minimum and maximum size.

It is not used in any filters currently and is inherently evil. If
passing binary data to filters is required in the future, it should be
done with some AVOptions-based system.

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

While here:
    - add missing .version and .category,
    - make .class_name consistent across filters,
    - align declarations.

Signed-off-by: Paul B Mahol <onemda@gmail.com>

This is more consistent with naming in the rest of Libav.

This will allow making AVFilterPad opaque for the calling apps, since
those are the only two fields that can be useful to the users.

The enabling symbol is renamed FF_AVFILTER_TRACE. Avoid conflicts with
the DEBUG macro, which may be defined for different purposes.

Return a const char *, fix warnings:
libavfilter/avfilter.c: In function ‘default_filter_name’:
libavfilter/avfilter.c:414:5: warning: return discards ‘const’ qualifier from pointer target type [enabled by default]
libavfilter/avfilter.c: At top level:
libavfilter/avfilter.c:419:5: warning: initialization from incompatible pointer type [enabled by default]
libavfilter/avfilter.c:419:5: warning: (near initialization for ‘avfilter_class.item_name’) [enabled by default]

The function was introduced in 4d6a8a2bdb and is not used anymore
outside avfilter.c.

This avoids to pollute the public API with an apparently unnecessary
function. The function was introduced a few days ago, so removing it from
the public API should do no much harm.

These utilities are meant to be defined in avfilter.c, since they are
generic and thus contain both audio and video code.

They are only useful inside filters and we don't allow user filters for
now.