It tracks whether the decoder for this stream ever produced any frames
and its only use is for checking whether a filter input ever received a
frame - those that did not are prioritized by the scheduler.
This is awkward and unnecessarily complicated - checking whether the
filtergraph input format is valid works just as well and does not
require maintaining an extra variable.
In case no decoder is available, dec_open() called from ist_use() will
fail with 'Decoding requested, but no decoder found', so this check is
redundant.
When a filtergraph input receives EOF but never saw any input frames, we
use the fallback parameters. Currently an attempt to actually configure
the filtergraph will happen elsewhere, but there is no reason to
postpone this.
With complex filtergraphs it can happen that the filtergraph is
unconfigured because some other filter than the one we just got EOF on
is missing parameters.
Make sure that the fallback parametes for a given input are only used
when that input is unconfigured.
The two checks using eof_reached are testing whether more input can
possibly appear on this filtergraph input. InputFilterPriv.eof is the
more authoritative source for this information.
When an input stream terminates and no frames were successfully decoded,
filtering code will currently configure the filtergraph using demuxer
stream parameters. Use decoder parameters instead, which should be more
reliable. Also, initialize them immediately when an input stream is
bound to a filtergraph input, so that these parameters are always
available (if at all) and filtering code does not need to reach into the
decoder at some arbitrary later point.
Set InputStream.decoding_needed/discard/etc. only from
ist_{filter,output},add() functions. Reduces the knowledge of
InputStream internals in muxing/filtering code.
The channel layout is set before opening the encoder, in enc_open().
Messing with it in configure_output_audio_filter() cannot accomplish
anything meaningful.
The code currently uses lavfi for this, which creates a sort of
configuration dependency loop - the encoder should be ideally
initialized with information from the first audio frame, but to get this
frame one needs to first open the encoder to know the frame size. This
necessitates an awkward workaround, which causes audio handling to be
different from video.
With this change, audio encoder initialization is congruent with video.
This is more correct, but was not possible before the recently-added
filtergraph parsing API.
Also, only pass hw devices to filters that are flagged as capable of
using them.
Tested-by: Niklas Haas
Many filters accept user-provided data that is cumbersome to provide as
text strings - e.g. binary files or very long text. For that reason such
filters typically provide a option whose value is the path from which
the filter loads the actual data.
However, filters doing their own IO internally is a layering violation
that the callers may not expect, and is thus best avoided. With the
recently introduced graph segment parsing API, loading option values
from files can now be handled by the caller.
This commit makes use of the new API in ffmpeg CLI. Any option name in
the filtergraph syntax can now be prefixed with a slash '/'. This will
cause ffmpeg to interpret the value as the path to load the actual value
from.
Instead of manually assembling the string, use av_dict_get_string
which handles things like proper escaping too (even though it is
not yet needed here).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Replace it with an array of streams in each InputFile. This is a more
accurate reflection of the actual relationship between InputStream and
InputFile.
Analogous to what was previously done to output streams in
7ef7a22251.
