Callers currently have two ways of adding filters to a graph - they can
either
- create, initialize, and link them manually
- use one of the avfilter_graph_parse*() functions, which take a
(typically end-user-written) string, split it into individual filter
definitions+options, then create filters, apply options, initialize
filters, and finally link them - all based on information from this
string.
A major problem with the second approach is that it performs many
actions as a single atomic unit, leaving the caller no space to
intervene in between. Such intervention would be useful e.g. to
- modify filter options;
- supply hardware device contexts;
both of which typically must be done before the filter is initialized.
Callers who need such intervention are then forced to invent their own
filtergraph parsing, which is clearly suboptimal.
This commit aims to address this problem by adding a new modular
filtergraph parsing API. It adds a new avfilter_graph_segment_parse()
function to parse a string filtergraph description into an intermediate
tree-like representation (AVFilterGraphSegment and its children).
This intermediate form may then be applied step by step using further
new avfilter_graph_segment*() functions, with user intervention possible
between each step.
Doxygen does not properly form references that span multiple levels,
so instead reword it a bit and manually add the references to what
they should point to.
This avoids unnecessary churn and build breakage for users, by
making sure the whole version.h is included like it has been so far,
while keeping the benefit of not needing to rebuild most files in
the ffmpeg tree on minor/micro bumps.
Signed-off-by: Martin Storsjö <martin@martin.st>
If one looks at the many query_formats callbacks in existence,
one will immediately recognize that there is one type of default
callback for video and a slightly different default callback for
audio: It is "return ff_set_common_formats_from_list(ctx, pix_fmts);"
for video with a filter-specific pix_fmts list. For audio, it is
the same with a filter-specific sample_fmts list together with
ff_set_common_all_samplerates() and ff_set_common_all_channel_counts().
This commit allows to remove the boilerplate query_formats callbacks
by replacing said callback with a union consisting the old callback
and pointers for pixel and sample format arrays. For the not uncommon
case in which these lists only contain a single entry (besides the
sentinel) enum AVPixelFormat and enum AVSampleFormat fields are also
added to the union to store them directly in the AVFilter,
thereby avoiding a relocation.
The state of said union will be contained in a new, dedicated AVFilter
field (the nb_inputs and nb_outputs fields have been shrunk to uint8_t
in order to create a hole for this new field; this is no problem, as
the maximum of all the nb_inputs is four; for nb_outputs it is only
two).
The state's default value coincides with the earlier default of
query_formats being unset, namely that the filter accepts all formats
(and also sample rates and channel counts/layouts for audio)
provided that these properties agree coincide for all inputs and
outputs.
By using different union members for audio and video filters
the type-unsafety of using the same functions for audio and video
lists will furthermore be more confined to formats.c than before.
When the new fields are used, they will also avoid allocations:
Currently something nearly equivalent to ff_default_query_formats()
is called after every successful call to a query_formats callback;
yet in the common case that the newly allocated AVFilterFormats
are not used at all (namely if there are no free links) these newly
allocated AVFilterFormats are freed again without ever being used.
Filters no longer using the callback will not exhibit this any more.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
It is unnecessary as the number of static inputs and outputs can now
be directly read via AVFilter.nb_(in|out)puts.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
It is intended as replacement for avfilter_pad_count(). In contrast to
the latter, it avoids a loop.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Up until now, an AVFilter's lists of input and output AVFilterPads
were terminated by a sentinel and the only way to get the length
of these lists was by using avfilter_pad_count(). This has two
drawbacks: first, sizeof(AVFilterPad) is not negligible
(i.e. 64B on 64bit systems); second, getting the size involves
a function call instead of just reading the data.
This commit therefore changes this. The sentinels are removed and new
private fields nb_inputs and nb_outputs are added to AVFilter that
contain the number of elements of the respective AVFilterPad array.
Given that AVFilter.(in|out)puts are the only arrays of zero-terminated
AVFilterPads an API user has access to (AVFilterContext.(in|out)put_pads
are not zero-terminated and they already have a size field) the argument
to avfilter_pad_count() is always one of these lists, so it just has to
find the filter the list belongs to and read said number. This is slower
than before, but a replacement function that just reads the internal numbers
that users are expected to switch to will be added soon; and furthermore,
avfilter_pad_count() is probably never called in hot loops anyway.
This saves about 49KiB from the binary; notice that these sentinels are
not in .bss despite being zeroed: they are in .data.rel.ro due to the
non-sentinels.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The last init_opaque callback has been removed in commit
07ffdedf784e86b88074d8d3e08e55752869562a; the opaque argument has been
always NULL since 0acf7e268b.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
It is unused since 02aa0701ae.
The corresponding size field is write-only since then.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
It is a private field that is unused since
44f660e7e7.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
It will allow to refernce it as a whole without clunky macros.
Most of the changes have been automatically made with sed:
sed -i '
s/-> *in_formats/->incfg.formats/g;
s/-> *out_formats/->outcfg.formats/g;
s/-> *in_channel_layouts/->incfg.channel_layouts/g;
s/-> *out_channel_layouts/->outcfg.channel_layouts/g;
s/-> *in_samplerates/->incfg.samplerates/g;
s/-> *out_samplerates/->outcfg.samplerates/g;
' src/libavfilter/*(.)
Not used by anything at all since we don't auto insert lavr filters.
Reviewed-by: wm4 <nfxjfg@googlemail.com>
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
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.
AVFilterLink.frame_count is supposed to count the number of frames
that were passed on the link, but with min_samples, that number is
not always the same for the source and destination filters.
With the addition of a FIFO on the link, the difference will become
more significant.
Split the variable in two: frame_count_in counts the number of
frames that entered the link, frame_count_out counts the number
of frames that were sent to the destination filter.
Also adds a new flag to mark filters which are aware of hwframes and
will perform this task themselves, and marks all appropriate filters
with this flag.
This is required to allow software-mapped hardware frames to work,
because we need to have the frames context available for any later
mapping operation in the filter graph.
The output from the filter graph should only propagate further to an
encoder if the hardware format actually matches the visible format
(mapped frames are valid here and have an hw_frames_ctx, but this
should not be given to the encoder as its hardware context).
Even though this is not part of the public API, some external
applications access fields after it, thus breaking after updating from
ffmpeg 3.0 or earlier.
Since it is not public, it can be freely moved to the end to avoid
that problem in the future.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Anton Khirnov
James Almer
Marvin Scholz
Martin Storsjö
Andreas Rheinhardt
Paul B Mahol
Andreas Rheinhardt
Nicolas George
Zhao Zhili
Josh de Kock
Mark Thompson
Vittorio Giovara
Rostislav Pehlivanov
Matthieu Bouron
Timothy Gu
Timo Rothenpieler