[FFmpeg-devel] [PATCH 2/8] swscale: Add swscale input support for Y210

Carl Eugen Hoyos ceffmpeg at gmail.com
Tue Jan 14 17:55:20 EET 2020


Am Di., 14. Jan. 2020 um 08:25 Uhr schrieb Fu, Linjie <linjie.fu at intel.com>:
>
> > -----Original Message-----
> > From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> > Carl Eugen Hoyos
> > Sent: Tuesday, January 14, 2020 12:42
> > To: FFmpeg development discussions and patches <ffmpeg-
> > devel at ffmpeg.org>
> > Subject: Re: [FFmpeg-devel] [PATCH 2/8] swscale: Add swscale input support
> > for Y210
> >
> >
> >
> > > Am 14.01.2020 um 04:20 schrieb Fu, Linjie <linjie.fu at intel.com>:
> > >
> > > Zitierten Inhalt anzeigen
> > >> -----Original Message-----
> > >> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> > >> Carl Eugen Hoyos
> > >> Sent: Monday, January 13, 2020 00:40
> > >> To: FFmpeg development discussions and patches <ffmpeg-
> > >> devel at ffmpeg.org>
> > >> Subject: Re: [FFmpeg-devel] [PATCH 2/8] swscale: Add swscale input
> > support
> > >> for Y210
> > >>
> > >>> Am So., 29. Dez. 2019 um 17:40 Uhr schrieb Linjie Fu
> > <linjie.fu at intel.com>:
> > >>>
> > >>> Add swscale input support for Y210, output support and fate
> > >>> test could be added later if there is requirement for software
> > >>> CSC to this packed format.
> > >>>
> > >>> Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> > >>> ---
> > >> format_entries[AV_PIX_FMT_NB] = {
> > >>>     [AV_PIX_FMT_YUVA444P12LE] = { 1, 1 },
> > >>>     [AV_PIX_FMT_NV24]        = { 1, 1 },
> > >>>     [AV_PIX_FMT_NV42]        = { 1, 1 },
> > >>> +    [AV_PIX_FMT_Y210BE]      = { 1, 0 },
> > >>> +    [AV_PIX_FMT_Y210LE]      = { 1, 0 },
> > >>
> > >> Am I correct that this functions only work on LE because the vaapi drivers
> > >> only exist for LE?
> > >
> > >
> > > The only output from VAAPI driver is Y210LE.
> >
> > But does the driver also exist on big-endian hardware? And was your
> > conversion routine tested on big-endian hardware?
>
> As far as I know from media-driver, there is no support on big-endian hardware,
> hence no testing for big endian conversion locally. To avoid any uncertainty, we
> can hold the big-endian support unless it's demanded someday.

Sorry for being unclear:
This patch is about libswscale and (by itself) unrelated to vaapi.
The patch must work on all platforms for which libswscale can be
compiled, that includes big-endian hardware. It looks to me as if
the patch will not work correctly (and in this case hopefully break
fate) on big-endian. If I am correct, the patch can not be committed.
(I did not test myself and could of course be wrong.)

I have no strong opinion if it makes sense to add code for
Y210BE or not, it may even be a possibility to only add
Y210 (native) which will likely simplify the patch, but I
fear fate will not like it.

Carl Eugen

PS:
As always, this would of course be much easier if no new
pix_fmt would be needed, apart from other developers'
opinions I still wonder if it wouldn't be much simpler for you
to do the conversion in your wrapper code...


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