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

[Hans de Goede <hdegoede@redhat.com>]

Hi All,

On 22-Apr-25 12:07 PM, Sakari Ailus wrote:
> Hi Hans,
> 
> On Mon, Apr 21, 2025 at 07:39:15PM +0200, Hans de Goede wrote:
>> Hi,
>>
>> 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.
> 
> If we discuss this topic in the Media summit, then it be discussed in the
> context of the metadata patch series
> <URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=metadata> and
> especially the Common raw sensor model rather than the current state of
> affair. We know what's in upstream right now is insufficient and what is
> documented there isn't fully supported in current drivers.

Hans, as Laurent says I think we can easily fill an hour with this,
so sat 45 min or 1 hour ?

Sakari, I agree we should probably base the dicussions on the new common
raw sensor model. I will make sure to have read all the current code / docs
on that before the summit. Can you maybe prepare some discussion points
for the summit based on this ?

Regards,

Hans