On Wed, May 31, 2023 at 02:26:11PM +0000, Anton Khirnov wrote:
> ffmpeg | branch: master | Anton Khirnov <anton@khirnov.net> | Tue May 23 22:54:23 2023 +0200| [20cacfe4936a8d5b643421b5ca93bb098f6b76dd] | committer: Anton Khirnov
> 
> fftools/ffmpeg: rework setting sub2video parameters
> 
> Set them in ifilter_parameters_from_dec(), similarly to audio/video
> streams. This reduces the extent to which sub2video filters need to be
> treated specially.
> 
> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=20cacfe4936a8d5b643421b5ca93bb098f6b76dd
> ---
> 
>  fftools/ffmpeg.c        |  6 ++---
>  fftools/ffmpeg_demux.c  | 21 ++++++++++++++++++
>  fftools/ffmpeg_filter.c | 58 +++++++++++++++----------------------------------
>  3 files changed, 41 insertions(+), 44 deletions(-)

This breaks subtitle location and size

./ffmpeg -i ~/tickets/4752/dump_dvbsubtitles.mp4 -y  -ss 5 -t 1 -filter_complex '[0:v][0:s]overlay' /tmp/file4752.ts && ffplay /tmp/file4752.ts

https://samples.ffmpeg.org/ffmpeg-bugs/trac/ticket4752/dump_dvbsubtitles.mp4


Before this commit the subtitles are centered at the bottom of the screen
after this patch the subtitles are tiny in the left middle of the screen

In the following case the subtitles disappear completely:

./ffmpeg -i ~/tickets/679/subtitles.ts -filter_complex '[0:v][0:s:0]overlay[vid]' -map  '[vid]' -bitexact  -t 3 file-4744-3.avi

https://samples.ffmpeg.org/ffmpeg-bugs/trac/ticket4744/subtitles.ts

[...]
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