[FFmpeg-devel] [PATCH 1/3] avutils/hwcontext: add derive-device function which searches for existing devices in both directions

[Soft Works]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of Mark
> Thompson
> Sent: Monday, May 2, 2022 12:01 AM
> To: ffmpeg-devel at ffmpeg.org
> Subject: Re: [FFmpeg-devel] [PATCH 1/3] avutils/hwcontext: add derive-
> device function which searches for existing devices in both directions

[..]

> >> * Whenever you use derivation it creates a circular reference, so
> the
> >> instances can never be freed in the current implementation.
> >
> > It's been a while...I thought there wasn't, but looking at it now,
> > it seems you are right.
> >
> > How would you solve it?
> 
> Hmm.  You do need both the source and derived device to be able to
> keep the other alive with this form, so the strict reference-counting
> structure isn't going to work.  Given that, I guess it's got to do
> something else but I've no idea what.

Ok, before I come up with something that might find objection, I'd like
to ask all around:

Do we have some pattern for weak/shared referencing via AVBufferRef?

Thanks
softworkz