[FFmpeg-devel] [RFC PATCH 4/5] tinterlace: Properly preserve CEA-708 closed captions

[Thomas Mundt]

Am So., 19. März 2023 um 00:22 Uhr schrieb Devin Heitmueller <
devin.heitmueller at ltnglobal.com>:

> On Sat, Mar 18, 2023 at 1:12 PM Thomas Mundt <tmundt75 at gmail.com> wrote:
> > Not all modes of tinterlace halve the frame rate. mergex2 and pad keep
> it, interlacex2 even doubles it.
>
> Sorry, I should have been more clear with the patch description in
> that I realize that interlacing doesn't necessarily halve the
> framerate, depending on the mode.  That said, I was pretty sure I got
> it working with all the code paths, but if you think I've missed one
> or more then please let me know.  Or if you have an alternative patch
> which you think is cleaner for the tinterlace filter, I would be happy
> to review it.
>
>
I haven't worked with closed captions yet and also don't have the expertise
to test them reliably.
I just would like to roughly understand as maintainer of the tinterlace
filter how your patch works in order not to break the functionality in
future changes.
Looking through it, I wonder for example why av_ccfifo_inject is set for
the interleave modes and not for the drop modes.
Under which conditions must av_ccfifo_inject be set? Whenever a frame is
created at the output of the filter, or are there other conditions?

Regards,
Thomas