Unlike av_frame_is_writable(), it uses the link's alloc callback,
making direct rendering possible.

The code comes from ff_filter_frame_framed(), moved with mostly
trivial changes.

Also introduce libavfilter/filters.h for all functions needed
to implement filters.

av_buffersink_get_frame_rate() did already exist; its argument becomes const.

The names are only used for technical output and debugging.
Make them similar to C identifiers for easier quick reading
of debug dumps.

CID: 1324298
add a label when error goto the label to release resource

Signed-off-by: Steven Liu <lq@chinaffmpeg.org>

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

The only thing we can do at such point is return samples unchanged.

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

Fixes CID1244189

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

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

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

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

This variable corresponds to the final scale of the adjustement for a
given color range.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

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

Fixes ffmpeg -h filter=transpose

Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Marton Balint <cus@passwd.hu>

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

Reduce peak memory consumption with ffmpeg in certain cases.

Fix an infinite loop in forward_status_change().

Signed-off-by: James Almer <jamrial@gmail.com>

Fixes coverity report.

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

With min_samples, if a frame arrives but is too small, it clears
frame_wanted_out. In most cases, the destination filter would be
activated again later because of frame_wanted_out on its own
outputs, but not sinks.
avfilter_graph_request_oldest() is doing the work of the sink
itself, and is therefore allowed to use frame_blocked_in.

Fix an infinite loop in forward_status_change().

Signed-off-by: Nicolas George <george@nsup.org>
Signed-off-by: Marton Balint <cus@passwd.hu>

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

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

Fix compilation on MSVC.

Steps to reproduce:
./ffmpeg_g -f s16be -i /dev/null -af atempo=0.5 -y /tmp/atempo.wav

Signed-off-by: Marton Balint <cus@passwd.hu>

A lot of changes happen at the same time:

- Add a framequeue fifo to AVFilterLink.

- split AVFilterLink.status into status_in and status_out: requires
  changes to the few filters and programs that use it directly
  (f_interleave, split, filtfmts).

- Add a field ready to AVFilterContext, marking when the filter is ready
  and its activation priority.

- Add flags to mark blocked links.

- Change ff_filter_frame() to enqueue the frame.

- Change all filtering functions to update the ready field and the
  blocked flags.

- Update ff_filter_graph_run_once() to use the ready field.

- buffersrc: always push the frame immediately.

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

Reported-by: Josh de Kock
Signed-off-by: Paul B Mahol <onemda@gmail.com>

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

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Marton Balint <cus@passwd.hu>

Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Marton Balint <cus@passwd.hu>

Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Marton Balint <cus@passwd.hu>

Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Marton Balint <cus@passwd.hu>

Since the default in the libav fork is to only allow known layouts, making
unknown layouts allowed by default here can be a security risk for filters
directly merged from libav. However, usually it is simple to detect such cases,
use of av_get_channel_layout_nb_channels is a good indicator, so I suggest we
change this regardless.

See http://ffmpeg.org/pipermail/ffmpeg-devel/2016-November/203204.html.

This patch indirectly adds unknown channel layout support for filters where
query_formats is not specified:

abench
afifo
ainterleave
anullsink
apad
aperms
arealtime
aselect
asendcmd
asetnsamples
asetpts
asettb
ashowinfo
azmq

It introduces a query_formats callback for the asyncts filter, which only
supports known channel layouts since it is using libavresample.

And it removes .query_formats callback from filters where it was only there to
support unknown layouts, as this is now the default:

aloop
ametadata
anull
asidedata
asplit
atrim

Acked-by: Nicolas George <george@nsup.org>
Signed-off-by: Marton Balint <cus@passwd.hu>

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

Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>