This exposes libplacebo's frame mixing functionality to vf_libplacebo,
by allowing users to specify a desired target fps to output at. Incoming
frames will be smoothly resampled (in a manner determined by the
`frame_mixer` option, to be added in the next commit).
To generate a consistently timed output stream, we directly use the
desired framerate as the timebase, and simply output frames in
sequential order (tracked by the number of frames output so far).
To present compatibility with the current behavior, we keep track of a
FIFO of exact frame timestamps that we want to output to the user. In
practice, this is essentially equivalent to the current filter_frame()
code, but this design allows us to scale to more complicated use cases
in the future - for example, insertion of intermediate frames
(deinterlacing, frame doubling, conversion to fixed fps, ...)
This does not leverage any immediate benefits, but refactors and
prepares the codebase for upcoming changes, which will include the
ability to do deinterlacing and resampling (frame mixing).
This commit contains no functional change. The goal is merely to
separate the highly intertwined `filter_frame` and `process_frames`
functions into their separate concerns, specifically to separate frame
uploading (which is now done directly in `filter_frame`) from emitting a
frame (which is now done by a dedicated function `output_frame`).
The overall idea here is to be able to ultimately call `output_frame`
multiple times, to e.g. emit several output frames for a single input
frame.
For example
ffmpeg -f lavfi -i sine -af "aformat=cl=stereo|5.1|7.1,lowpass,aformat=cl=7.1|5.1|stereo" -f null -
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
Before this commit if allocation would fail in ff_add_channel_layout()
function, function would return negative error code and this would
cause wrong format pick up later. If allocation would not fail return
code would be 0 and then format negotiation would simply fail as code
would break from the loop but with wrong return code.
Error was introduced in 6aaac24d72 commit.
Fixes#6638
This is not public API, no it has no need for an alloc() and free()
functions. The struct can reside on stack.
Signed-off-by: James Almer <jamrial@gmail.com>
THis filter can correct certain issues seen from upstream sources
where the cc_count is not properly set or the CEA-608 tuples are
not at the start of the payload as expected.
Make use of the ccfifo to extract and immediately repack the CEA-708
side data, thereby removing any extra padding and ensuring the 608
tuples are at the front of the payload.
Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
Because the interlacing filter halves the effective framerate, we
need to ensure that no CEA-708 data is lost as frames are merged.
Make use of the new ccfifo mechanism to ensure that caption data
is properly preserved as frames pass through the filter.
Thanks to Thomas Mundt for review and noticing a couple of
missed codepaths for injection on output. Thanks to Lance Wang
for pointing out a memory leak.
Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
Various deinterlacing modes have the effect of doubling the
framerate, and we need to ensure that the caption data isn't
duplicated (or else you get double captions on-screen).
Use the new ccfifo mechanism for yadif (and yadif_cuda and bwdif
since they use the same yadif core) so that CEA-708 data is
properly preserved through this filter.
Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
The existing implementation made an attempt to remove duplicate
captions if increasing the framerate, but made no attempt to
handle reducing the framerate, nor did it rewrite the caption
payloads to have the appropriate cc_count (e.g. the cc_count needs
to change from 20 to 10 when going from 1080i59 to 720p59 and
vice-versa).
Make use of the new ccfifo mechanism to ensure that caption data
is properly preserved.
Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
When transcoding video that contains 708 closed captions, the
caption data is tied to the frames as side data. Simply dropping
or adding frames to change the framerate will result in loss of
data, so the caption data needs to be preserved and reformatted.
For example, without this patch converting 720p59 to 1080i59
would result in loss of 50% of the caption bytes, resulting in
garbled 608 captions and 708 probably wouldn't render at all.
Further, the frames that are there will have an illegal
cc_count for the target framerate, so some decoders may ignore
the packets entirely.
Extract the 608 and 708 tuples and insert them onto queues. Then
after dropping/adding frames, re-write the tuples back into the
resulting frames at the appropriate rate given the target
framerate. This includes both having the correct cc_count as
well as clocking out the 608 pairs at the appropriate rate.
Thanks to Lance Wang <lance.lmwang@gmail.com>, Anton
Khirnov <anton@khirnov.net>, and Michael Niedermayer <michael@niedermayer.cc>
for providing review/feedback.
Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
