[FFmpeg-devel] [PATCH v16 01/16] global: Prepare AVFrame for subtitle handling

[Soft Works]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of Anton
> Khirnov
> Sent: Saturday, November 27, 2021 10:25 AM
> To: FFmpeg development discussions and patches <ffmpeg-devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH v16 01/16] global: Prepare AVFrame for
> subtitle handling
> 
> Quoting Andreas Rheinhardt (2021-11-27 10:06:35)
> > Anton Khirnov:
> > >
> > > Not sure whether this was asked already - why do we need this new
> > > function? Seems to me you can accomplish the same thing by just adding
> > > the type field to AVFrame. Then
> > > - if type is AVMEDIA_TYPE_SUBTITLE -> allocate a subtitle
> > > - if type is AVMEDIA_TYPE_{VIDEO,AUDIO} -> allocate video/audio
> > > - otherwise detect video/audio as we do now
> > >
> >
> > https://ffmpeg.org/pipermail/ffmpeg-devel/2021-September/285185.html
> 
> So IIUC the only concern is that a user might "manually" unref the frame
> without calling av_frame_unref(). I would say that this is already
> illegal, because we can (and did) add new allocated objects to AVFrame
> that would break things if you just kept them from one frame to the
> other (especially of a different type), e.g. hw_frames_ctx.
> 

The earlier conversation (from v3 of the patchset) explains it better.
This is what I quoted. Here's the link to it on patchwork:

https://patchwork.ffmpeg.org/project/ffmpeg/patch/MN2PR04MB5981A454384CFC369522E875BAD79@MN2PR04MB5981.namprd04.prod.outlook.com/

sw