[FFmpeg-devel] [FFmpeg-cvslog] avfilter/vf_tpad: if there is no frame to clone return early

Paul B Mahol onemda at gmail.com
Fri Feb 25 09:51:53 EET 2022


On Thu, Feb 24, 2022 at 11:21 PM Thierry Foucu <tfoucu at gmail.com> wrote:

> On Thu, Feb 24, 2022 at 2:19 PM Thierry Foucu <tfoucu at gmail.com> wrote:
>
> >
> >
> > On Thu, Feb 24, 2022 at 1:50 PM Paul B Mahol <onemda at gmail.com> wrote:
> >
> >> On Thu, Feb 24, 2022 at 10:36 PM Thierry Foucu <tfoucu at gmail.com>
> wrote:
> >>
> >> > On Thu, Feb 24, 2022 at 1:28 PM Paul B Mahol <onemda at gmail.com>
> wrote:
> >> >
> >> > > On Thu, Feb 24, 2022 at 10:12 PM Thierry Foucu <tfoucu at gmail.com>
> >> wrote:
> >> > >
> >> > > > On Thu, Feb 24, 2022 at 12:30 PM Paul B Mahol <git at videolan.org>
> >> > wrote:
> >> > > >
> >> > > > > ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Thu
> >> Feb
> >> > 24
> >> > > > > 20:32:41 2022 +0100| [3715f2f8643695940582ce040b7a052cccfb9db2]
> |
> >> > > > > committer: Paul B Mahol
> >> > > > >
> >> > > > > avfilter/vf_tpad: if there is no frame to clone return early
> >> > > > >
> >> > > > > >
> >> > > > >
> >> > > >
> >> > >
> >> >
> >>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3715f2f8643695940582ce040b7a052cccfb9db2
> >> > > > > ---
> >> > > > >
> >> > > > >  libavfilter/vf_tpad.c | 5 +++++
> >> > > > >  1 file changed, 5 insertions(+)
> >> > > > >
> >> > > > > diff --git a/libavfilter/vf_tpad.c b/libavfilter/vf_tpad.c
> >> > > > > index e5acece1e4..120dbcb4d3 100644
> >> > > > > --- a/libavfilter/vf_tpad.c
> >> > > > > +++ b/libavfilter/vf_tpad.c
> >> > > > > @@ -148,6 +148,11 @@ static int activate(AVFilterContext *ctx)
> >> > > > >                                frame->data, frame->linesize,
> >> > > > >                                0, 0, frame->width,
> frame->height);
> >> > > > >          } else if (s->stop_mode == 1) {
> >> > > > > +            if (!s->cache_stop) {
> >> > > > > +                s->pad_stop = 0;
> >> > > > > +                ff_outlink_set_status(outlink, AVERROR_EOF,
> >> s->pts);
> >> > > > > +                return 0;
> >> > > > > +            }
> >> > > > >              frame = av_frame_clone(s->cache_stop);
> >> > > > >              if (!frame)
> >> > > > >                  return AVERROR(ENOMEM);
> >> > > > >
> >> > > > >
> >> > > > The problem with this solution is that the tpad will then not do
> >> what
> >> > we
> >> > > > are expecting, which is padding video track, and the output file
> >> will
> >> > not
> >> > > > have the desired duration.
> >> > > > Will it not be better to just output black frame (aka stop_mode ==
> >> 0) ,
> >> > > > something like that?
> >> > > >
> >> > >
> >> > > I doubt that, clone is clone, there is no point in padding stream
> that
> >> > have
> >> > > no frames at all.
> >> > >
> >> > >
> >> > >
> >> > The sample I forwarded to JB has video frames. The problem was that
> >> there
> >> > was a re-init of the filter chain after a resolution change and after
> >> the
> >> > re-init, there were no frames but got frames before the re-init.
> >> > I will understand for a media file which has NEVER received a video
> >> frame
> >> > and in this case, this is the correct solution.
> >> >
> >>
> >> Hmm, so you encode output with resolution change, why not use scale
> filter
> >> as first filter and then no resolution ever change for rest of graph?
> >> Adding support for resolution changes to all filters is very time
> >> consuming
> >> task and I see no real benefit in doing that now.
> >>
> >
> > We do have the scale filter in front of the tpad filter. Here is the
> > filter chain we are using
> >
> >
> idet=1.04:1.5,yadif=0:-1:1,scale=+528:+864:flags=bicubic,setsar=1,fps=fps=16.601,tpad=stop_mode=clone:stop_duration=2808ms
> >
>

Is this just increasing size instead of setting constant one?


> > And it does crash.
> >
> > Even just fps=fps=16.601,tpad=stop_mode=clone:stop_duration=2808ms
> > reproduce the problem.
> >
>
> Maybe an option to the tpad filter to decide what should be the output when
> the stop_mode == 1 and cache_stop is NULL?
> So, in some cases, people may want a color frame, and some other will just
> want to exit right away?
>

That is too much for a special option.

>
>
> >
> >
> >>
> >>
> >> >
> >> >
> >> > > >
> >> > > > iff --git a/libavfilter/vf_tpad.c b/libavfilter/vf_tpad.c
> >> > > > index e5acece1e4..5e4062e9f2 100644
> >> > > > --- a/libavfilter/vf_tpad.c
> >> > > > +++ b/libavfilter/vf_tpad.c
> >> > > > @@ -140,7 +140,7 @@ static int activate(AVFilterContext *ctx)
> >> > > >              ff_outlink_set_status(outlink, AVERROR_EOF, s->pts);
> >> > > >              return 0;
> >> > > >          }
> >> > > > -        if (s->stop_mode == 0) {
> >> > > > +        if (s->stop_mode == 0 || !s->cache_stop) {
> >> > > >              frame = ff_get_video_buffer(outlink, outlink->w,
> >> > > outlink->h);
> >> > > >              if (!frame)
> >> > > >                  return AVERROR(ENOMEM);
> >> > > >
> >> > > >
> >> > > >
> >> > > >
> >> > > > > _______________________________________________
> >> > > > > ffmpeg-cvslog mailing list
> >> > > > > ffmpeg-cvslog at ffmpeg.org
> >> > > > > https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
> >> > > > >
> >> > > > > To unsubscribe, visit link above, or email
> >> > > > > ffmpeg-cvslog-request at ffmpeg.org with subject "unsubscribe".
> >> > > > >
> >> > > >
> >> > > >
> >> > > > --
> >> > > >
> >> > > > Thierry Foucu
> >> > > > _______________________________________________
> >> > > > ffmpeg-devel mailing list
> >> > > > ffmpeg-devel at ffmpeg.org
> >> > > > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >> > > >
> >> > > > To unsubscribe, visit link above, or email
> >> > > > ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
> >> > > >
> >> > > _______________________________________________
> >> > > ffmpeg-devel mailing list
> >> > > ffmpeg-devel at ffmpeg.org
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> >> > >
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> >> > > ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
> >> > >
> >> >
> >> >
> >> > --
> >> >
> >> > Thierry Foucu
> >> > _______________________________________________
> >> > ffmpeg-devel mailing list
> >> > ffmpeg-devel at ffmpeg.org
> >> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >> >
> >> > To unsubscribe, visit link above, or email
> >> > ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
> >> >
> >> _______________________________________________
> >> ffmpeg-devel mailing list
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> >>
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> >>
> >
> >
> > --
> >
> > Thierry Foucu
> >
>
>
> --
>
> Thierry Foucu
> _______________________________________________
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