Re: [ANN] Media Summit May 13th: Draft Agenda (v2)

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Tue, Apr 22, 2025 at 10:01:38AM +0200, Hans Verkuil wrote:
> On 21/04/2025 19:39, Hans de Goede wrote:
> > On 21-Apr-25 2:31 PM, Hans Verkuil wrote:
> >> Hi all,
> >>
> >> Here is my v2 of the draft agenda for the media summit. The only changes
> >> are dropping Sebastian's email and fixing Devarsh' email.
> >>
> >> As always, this draft agenda is subject to change and all times are guesstimates!
> >>
> >> Please note that I am transitioning from my old hverkuil@xs4all.nl email to
> >> my new hans@jjverkuil.nl email. If you have problems replying to that new email,
> >> please let me know and just send it to the old email (that won't go away).
> >>
> >> The Media Summit will be held Tuesday May 13th to coincide with
> >> the Embedded Recipes Conference in Nice, France:
> >>
> >> https://embedded-recipes.org/2025/
> >>
> >> Note that there are also some workshops held after this conference:
> >>
> >> https://embedded-recipes.org/2025/workshops/
> >>
> >> And a gStreamer hackfest:
> >>
> >> https://discourse.gstreamer.org/t/gstreamer-spring-hackfest-2025-on-16-18-may-2025-in-nice-france/4366
> >>
> >> The Media Summit will be held at Hotel Campanile:
> >>
> >> https://nice-aeroport.campanile.com/en-us/
> >>
> >> It is close to the Airport and to the Embedded Recipes venue.
> >>
> >> The meeting room can hold up to 30 people and has video conferencing support; it is
> >> sponsored by Collabora and Cisco Systems Norway.
> >>
> >> We currently have the following confirmed in-person attendees:
> >>
> >> Sakari Ailus <sakari.ailus@linux.intel.com> (Intel)
> >> Mauro Carvalho Chehab <mchehab+huawei@kernel.org> (Media Maintainer, Huawei)
> >> Nicolas Dufresne <nicolas.dufresne@collabora.com> (Collabora)
> >> Hans de Goede <hdegoede@redhat.com> (RedHat)
> >> Paul Kocialkowski <paulk@sys-base.io> (sys-base)
> >> Jai Luthra <jai.luthra@ideasonboard.com> (Ideas on Board)
> >> Laurent Pinchart <laurent.pinchart@ideasonboard.com> (Ideas on Board)
> >> Ricardo Ribalda <ribalda@chromium.org> (Google)
> >> Maxime Ripard <mripard@redhat.com> (RedHat)
> >> Devarsh Thakkar <devarsht@ti.com> (Texas Instruments)
> >> Hans Verkuil <hans@jjverkuil.nl> (Media Maintainer, Cisco Systems Norway)
> >> Arthur Vinchon <arthur.vinchon@allegrodvt.com> (Allegro DVT)
> >>
> >> As you can see, there is enough room for more people, so don't hesitate to
> >> register by sending an email to me. The deadline is May 2nd.
> >>
> >> And the following remote participants:
> >>
> >> Marco Felsch <m.felsch@pengutronix.de> (Pengutronix)
> >> Martin Hecht <mhecht73@googlemail.com> (Avnet Silica)
> >> Hu, Jerry W <jerry.w.hu@intel.com> (Intel)
> >> jackson.lee <jackson.lee@chipsnmedia.com> (Chips 'n Media)
> >> Mirela Rabulea <mirela.rabulea@nxp.com> (NXP)
> >> Michael Tretter <m.tretter@pengutronix.de> (Pengutronix)
> >>
> >> Note: information on how to connect remotely will come later.
> >>
> >> If any information above is incorrect, or if I missed someone, then please let me know asap.
> >>
> >> Draft Agenda:
> >>
> >> 9:00-9:30: Get settled :-)
> >>
> >> 9:30-9:40: Hans Verkuil: Quick introduction
> >>
> >> 9:40-10:30: Jai Luthra: Per-stream V4L2 controls
> >>
> >> 10:30-11:15: Paul Kocialkowski: Stateless video encoding uAPI
> >>
> >> 11:15-11:30: break
> >>
> >> 11:30-12:15: Ricardo Ribalda: Openness Framework for ISPs
> >>
> >> 12:15-13:30: lunch TBD
> >>
> >> 13:30-14:00: Laurent Pinchart: Review of the status of staging drivers
> >>
> >> 14:00-15:00: Hans Verkuil: Status of Media CI/Multi-committers
> >>
> >> 15:00-17:00: TDB
> > 
> > As discussed here:
> > 
> > https://lore.kernel.org/linux-media/6cf8d6db-c24e-461b-bd7d-a3dad25e4945@redhat.com/
> > 
> > there are a bunch of V4L2 (subdev) API things which need
> > to be specified better (without leaving room for interpretation)
> > surrounding sensors. One of these is how to calculate the pixelrate
> > (and thus the FPS) for sensors when e.g. binning is used.
> > 
> > For non binning the pixelrate in pixels/second is:
> > 
> > pixelrate = (format.width + hblank) * (format.height + vblank) * fps
> > 
> > But what about binning, should the sensor driver then report the
> > skipped pixels as extra vblank (AFAICT that is what it looks like
> > on the CSI-2 bus) or should userspace know binning is happening and do:
> > 
> > (format.width * hscale + hblank) * (format.height *vscale + vblank)
> > 
> > and in that case how can userspace know hscale / vscale since atm
> > it cannot explicitly set those, but this is determined by the sensor
> > drivers.
> > 
> > There are a number of questions like these surrounding the V4L2 subdev
> > API for sensors, which IMHO would be good to discuss.
> 
> Thank you. I added this topic to the draft agenda. Do you have a
> guesstimatefor the time you need for this?

We could spend the whole day discussing raw sensors :-) If time permits,
extending this topic to discuss how to standardize exposing binning and
skipping to userspace.

-- 
Regards,

Laurent Pinchart