[FFmpeg-devel] Politics

[Soft Works]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of Paul B
> Mahol
> Sent: Saturday, December 18, 2021 11:27 AM
> To: FFmpeg development discussions and patches <ffmpeg-devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] Politics
> 
> On Wed, Dec 15, 2021 at 2:34 PM Soft Works <softworkz at hotmail.com> wrote:
> 

[..]

> > > > Once for the facts: the subtitle_pts field in AVFrame exists since
> > > > V5 of my patchset, which I have submitted on 2021-09-12.
> > > > This has been 3 months ago. Nobody had objected its existence
> > > > until only 2 or 3 weeks ago.
> > >
> > >
> > > This is really irrelevant, please stop insisting on hacks like
> > subtitle_pts.
> >
> > New idea:
> >
> > I could remove the three fields (subtitle_pts, subtitle_start_time,
> > subtitle_end_time) from AVFrame and add it to AVSubtitleArea.
> >
> > How about that? It would allow the frame to be "clean" at least.
> >
> 
> 
> Yea, much better, But still original issue is not solved.

Yes, correct, this changes the location but not the logic.
But this is something I could surely do. It's a bit of work, 
but it would be safe to do without breaking everything into
dysfunctional pieces ;-)

It wouldn't be my first choice since there can be multiple
AVSubtitleAreas while only those values from the first one
would be relevant. But when this would help to increase the
acceptance, then it will be fine for me.

Another possibility I had thought about, might be to leave
them at the side of AVFrame, but put them in a struct field
of AVFrame named 'subtitle_timing', which itself would have
the fields pts, start_time, end_time.


I did some research regarding the use of the start_time
field. While it is used and cannot be dropped, I found
that the following changes would be possible with moderate
effort:

- change the time base of start_time and end_time
  to the same like subtitle_pts (AV_TIMEBASE_Q)
- rename subtitle_start_time to subtitle_start_offset
- rename subtitle_end_time to subtitle_duration
  and adapt the logic everywhere where it's used

In combination with the subtitle_timing struct idea it 
could then look like:

frame->subtitle_timing.pts
frame->subtitle_timing.start_offset
frame->subtitle_timing.duration

or even eliminate the pts naming and do like:

frame->subtitle_timing.start
frame->subtitle_timing.start_offset
frame->subtitle_timing.duration

or still move them to AVSubtitleArea, which wouldn't 
be that nice to access and require to check the
subtitle_area_nb value wherever it needs to be
accessed:

frame->subtitle_areas[0].start
frame->subtitle_areas[0].start_offset
frame->subtitle_areas[0].duration


Please let me (all) know whether one of those suggestions would
be an acceptable compromise.


PS: I'll respond to the other question shortly

Thanks,
softworkz