[FFmpeg-devel] [PATCH] avfilter/avfilter: Fix hardcoded input index

[Paul B Mahol]

On Sun, Sep 5, 2021 at 9:44 PM Soft Works <softworkz at hotmail.com> wrote:

>
>
> > -----Original Message-----
> > From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> > Soft Works
> > Sent: Sunday, 5 September 2021 16:59
> > To: FFmpeg development discussions and patches <ffmpeg-
> > devel at ffmpeg.org>
> > Subject: Re: [FFmpeg-devel] [PATCH] avfilter/avfilter: Fix hardcoded
> > input index
> >
> >
> >
> > > -----Original Message-----
> > > From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> > > Paul B Mahol
> > > Sent: Sunday, 5 September 2021 11:01
> > > To: FFmpeg development discussions and patches <ffmpeg-
> > > devel at ffmpeg.org>
> > > Subject: Re: [FFmpeg-devel] [PATCH] avfilter/avfilter: Fix
> > hardcoded
> > > input index
> > >
> > > With what filters this happens?
> > >
> > > IIUC this is forbidden and such filters should use .activate
> > instead.
> >
> > The hardcoded [0] is wrong, no matter what the use case is.
> >
> > But to answer your question: It's about a new overlay_textsubs filter
> > where framesync cannot be used and incoming frames (video on input0,
> > subs on input1) need to be processed independently: the subtitle
> > events
> > are fed into the ass library (you could practically feed all events
> > in advance) while the overlay image generation is done based on a
> > given
> > time code.
> > This works fine by having a separate .filter_frame function for each
> > input (after applying this patch).
>
> BTW
>
> > > IIUC this is forbidden and such filters should use .activate
>
> The scale2ref filter is set up in the same way (two .filter_frame
> functions, no .activate, no framesync), probably because - like in
> my case - the filter must not sync frames across inputs.
>

FYI .activate does not sync frames across inputs.


>
> softworkz
>
>
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