On Thu, May 04, 2023 at 06:02:16PM -0400, Devin Heitmueller wrote:
> 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>
> ---
>  libavfilter/vf_fps.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)

breaks fate

make -j32 fate-filter-fps-down-eof-pass
...
==28512== Invalid read of size 8
==28512==    at 0x11754A0: av_fifo_freep2 (in /home/michael/ffmpeg-git/ffmpeg/ffmpeg_g)
==28512==    by 0x5A40F3: ff_ccfifo_freep (in /home/michael/ffmpeg-git/ffmpeg/ffmpeg_g)
==28512==    by 0x2570D1: uninit (in /home/michael/ffmpeg-git/ffmpeg/ffmpeg_g)
==28512==    by 0x34C1E2: avfilter_free (in /home/michael/ffmpeg-git/ffmpeg/ffmpeg_g)
==28512==    by 0x34DCC3: avfilter_graph_free (in /home/michael/ffmpeg-git/ffmpeg/ffmpeg_g)
==28512==    by 0x2FCD32: init_complex_filtergraph (in /home/michael/ffmpeg-git/ffmpeg/ffmpeg_g)
==28512==    by 0x30F5F5: ffmpeg_parse_options (in /home/michael/ffmpeg-git/ffmpeg/ffmpeg_g)
==28512==    by 0x2F1254: main (in /home/michael/ffmpeg-git/ffmpeg/ffmpeg_g)
==28512==  Address 0x0 is not stack'd, malloc'd or (recently) free'd


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Old school: Use the lowest level language in which you can solve the problem
            conveniently.
New school: Use the highest level language in which the latest supercomputer
            can solve the problem without the user falling asleep waiting.