[FFmpeg-devel] [PATCH] lavc/qsvenc_h264: don't support P010 format

[Soft Works]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> James Almer
> Sent: Saturday, November 26, 2022 12:25 AM
> To: ffmpeg-devel at ffmpeg.org
> Subject: Re: [FFmpeg-devel] [PATCH] lavc/qsvenc_h264: don't support
> P010 format
> 
> On 11/25/2022 8:20 PM, Soft Works wrote:
> >
> >
> >> -----Original Message-----
> >> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> >> James Almer
> >> Sent: Friday, November 25, 2022 8:48 PM
> >> To: ffmpeg-devel at ffmpeg.org
> >> Subject: Re: [FFmpeg-devel] [PATCH] lavc/qsvenc_h264: don't
> support
> >> P010 format
> >>
> >> On 11/25/2022 3:03 PM, Soft Works wrote:
> >>>
> >>>
> >>>> -----Original Message-----
> >>>> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf
> Of
> >>>> Anton Khirnov
> >>>> Sent: Friday, November 25, 2022 2:46 PM
> >>>> To: FFmpeg development discussions and patches <ffmpeg-
> >>>> devel at ffmpeg.org>
> >>>> Cc: Haihao Xiang <haihao.xiang at intel.com>
> >>>> Subject: Re: [FFmpeg-devel] [PATCH] lavc/qsvenc_h264: don't
> >> support
> >>>> P010 format
> >>>>
> >>>> Why?
> >>>
> >>> It's rarely used. There's not even a hwaccel that can decode
> this.
> >>
> >> The dxva2/d3d11 hwaccels seemingly do
> >
> > No, only for HEVC and VP9. Probably for AV1 as well  in the near
> future.
> 
> Well, then that is a good reason to not remove support in this
> encoder
> for a pixel format that not only our software scaler can generate,
> but
> decoders using hwaccel backends can output too.

That would be right when QSV would support it, but it doesn't,
neither for decoding nor for encoding and there are no plans to 
implement it.

I know this, because I had checked back with Intel on it, as I 
had been wondering about the existence of the MFX_PROFILE_AVC_HIGH10
constant, which is the profile for H.264 10bit encoding.

It existed because an earlier version of MSDK had supported this,
but only with their software implementations of H.264, never with
HWA. And unlikely with ffmpeg as that constant has never been used
there.

Nvidia doesn't support it either. Neither decoding nor encoding.
They don't even have a GUID constant mapping for the profile.

https://www.ffmpeg.org/doxygen/3.2/nvEncodeAPI_8h_source.html
(Line 151-)

Best wishes,
softworkz