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.
It does no initialization anymore, except for setting
transcode_init_done - the bulk of the function is printing the
input/output maps. It also cannot fail anymore, so remove the useless
return value.
Export the corresponding flag in InputFile instead. This will allow
making the demuxer AVFormatContext private in future commits, similarly
to what was previously done for muxers.
There is no point in having a per-stream wallclock start time, since
they are all computed at the same instant. Keep a per-file start time
instead, initialized when the demuxer thread starts.
That is a more appropriate place for this code and will allow hiding
more of InputStream.
The value of repeat_pict extracted from libavformat internal parser no
longer needs to be trasmitted outside of the demuxing thread.
Move readrate handling to the demuxer thread. This has to be done in the
same commit, since it reads InputStream.dts,nb_packets, which are now
set in the demuxer thread.
This way computing it and using it for streamcopy does not need to
happen in sync. Will be useful in following commits, where updating
InputStream.dts will be moved to the demuxing thread.
This code runs post-demuxing and is not synchronized with the decoder
output (which may be delayed with respect to its input by arbitrary and
unknowable amounts), so accessing any decoder properties is incorrect.
Move them to a separate function called right after timestamp
discontinuity processing. This is now possible, since these values have
no interaction with decoding anymore.
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.
When no frames are ever seen by an encoder, encoder flush will do a
last-ditch attempt to configure its source filtergraph in order to at
least get the stream parameters. This involves extracting demuxer
parameters from filtergraph source inputs, which is
* a bad layering violation
* probably unreachable, because decoders are flushed before encoders,
which should call ifilter_send_eof(), which will also set these
parameters; however due to complex control flow it is hard to be
entirely sure this code can never be triggered
Even if this code can actually be reached, it is probably better to
return an error as the comment above it says.
Anton Khirnov
James Almer