[FFmpeg-devel] [PATCH v1 1/9] lavu/pix_fmt: add P012 pixel format

[Carl Eugen Hoyos]

Am Fr., 21. Jan. 2022 um 06:56 Uhr schrieb Xiang, Haihao
<haihao.xiang-at-intel.com at ffmpeg.org>:
>
> > -----Original Message-----
> > From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of Xiang,
> > Haihao
> > Sent: Tuesday, June 30, 2020 15:34
> > To: ffmpeg-devel at ffmpeg.org
> > Subject: Re: [FFmpeg-devel] [PATCH v1 1/9] lavu/pix_fmt: add P012 pixel
> > format
> >
> > > Am So., 28. Juni 2020 um 23:01 Uhr schrieb Mark Thompson <sw at jkqxz.net>:
> > >
> > > > FFmpeg has always used pixfmt as defining both the memory layout
> > > > and which bits are used in that (so, for example, ARGB and 0RGB
> > > > are not the same thing)
> > >
> > > But they have the same bitdepth per component...
>
> > Agree with Mark. P012 and P016 have different significant bits, we should use
> > different pixfmts, otherwise an extra field in AVFrame is needed for bit depth.
> >
> > BTW there are the YUV420P variants for 10 / 12 / 14 / 16 bit in FFmpeg, it
> > would be better to follow FFmpeg's style to introduce P012 format instead
> > of reusing P016.

I was under the impression that YUV420P12 is much more different from
YUV420P16 than P012 from P016: Did I misunderstand?
(Reading the thread again, I don't think I did)

> Sorry for picking up this old thread.
>
> We'd like to add the support for 12bit decoding / encoding in VAAPI and QSV.
> Is there any other concern if adding P012 in FFmpeg ?

Did you already explain why you cannot use P016 or in which situation
it would create a different output?

Carl Eugen