On 13.05.24 13:18, Albert Esteve wrote:
On Mon, May 13, 2024 at 11:56 AM Alexander Gordeev
<alexander.gordeev@xxxxxxxxxxxxxxx
<mailto:alexander.gordeev@xxxxxxxxxxxxxxx>> wrote:
+CC Matti
Hi Albert,
On 10.05.24 15:43, Albert Esteve wrote:
> Hi,
>
> This a formal attempt of including virtio-media
> device specification.
>
> Virtio-media came from a discussion on virtio-dev
> mailing list, which lead to presenting virtio-v4l2[1]
> specification as an alternative to virtio-video.
>
> Later, virtio-v4l2 was renamed to virtio-media[2]
> and published through:
>
> https://github.com/chromeos/virtio-media
<https://github.com/chromeos/virtio-media>
>
> The repository above includes a guest V4L2 driver able
> to pass v4l2-compliance when proxying the vivid/vicodec
> virtual devices or an actual UVC camera using the
> crosvm V4L2 proxy device. Steps to reproduce are
> also detailed[3].
>
> There is some overlap with virtio-video in regards
> to which devices it can handle. However,
> as virtio-media will likely be the virtualization
> solution for ChromeOS (already landed into the chromeos
> organization) and possibly other Google projects for
> media devices, it would be desirable to include the
> specification in the next virtio release despite
> the aforementioned overlap.
Well, last year Cornelia made it clear, that this kind of overlap is
not
desirable in the specification. After long email discussion we had a
video call with some selected experts on June 1st discussing the
proposed approaches. The conclusion was that virtio-video development
should be continued, that the virtio-v4l2 use-case is valid, but the
proposed approach is not desirable in the specification, it should be
instead implemented with multiple device types. It was also concluded,
that a new device ID should not be reserved. It is a pity, that there
were no public announcement after that, so now it looks like we're
going
to have the same debate again. But I'll be happy to discuss all of this
with Albert and the new joiners in the discussion. I believe my
arguments are still valid.
Hi Alexander,
My intention is not to re-open the debate. The debate already happened
and the points given were clear enough. I will certainly noy be able to
enrich the debate with my own points. Sadly, we did not get a clear
conclusion, nor an agreement, on the way to move forward.
Instead, we ended up with two different specifications, one
that is still working towards standarization, one that did not.
I completely agree with Cornelia, the overlap is not desirable. I
really wish there had been an agreement and moved together
towards a common goal. But alas, that did not happen. And I
think that having a non-standard virtual device used in some
systems is the worst case, and hence decided to attempt
standardization.
Thanks for the clarification!
Yeah, I also wish we could move together to a common goal. But it looks
like we have different sets of requirements and therefore quite
different short term goals. I hope virtio-video can become suitable for
all of us in the long term, if there is also the virtio-camera, so that
the compatibility is much less a problem.
I suggest, that at least both of us (and hopefully others) start with
familiarizing ourselves with both virtio-video and virtio-media. I'd be
happy to present the current state of the virtio-video spec in details
and answer questions in a video call. I think, I'll need two weeks to
prepare. Maybe we can even resolve the issue ourselves. I think that
would be a good start. WDYT?
I am more or less familiar with virtio-video (not so much in the latest
drops, but I still checked them). But I do not own virtio-media, or have
any intellectual involvement in its design. I merely followed its
progress, and decided to collect the specification written at
https://github.com/chromeos/virtio-media
<https://github.com/chromeos/virtio-media>.
So I am in no position to solve the issue. But I decided to try
and alleviate its impact by having both in the standard.
That said, I will read your next virtio-video drop and try to
provide feedback :)
Thanks, looking forward to your feedback. :)
BR,
Albert
> The device ID in this document differs from
> the ID in the virtio-media project repository.
> And it will probably need some discussion on which
> would be the correct definitive ID.
>
> Full PDF:
https://drive.google.com/file/d/1PG1YxzbSvQHPphFhbUKyKKdvuwO6shyi/view?usp=sharing <https://drive.google.com/file/d/1PG1YxzbSvQHPphFhbUKyKKdvuwO6shyi/view?usp=sharing>
> PDF with the media section only:
https://drive.google.com/file/d/1Y7kAGzlUfl30VIUx9wQtz5sFTkWnBiyA/view?usp=sharing <https://drive.google.com/file/d/1Y7kAGzlUfl30VIUx9wQtz5sFTkWnBiyA/view?usp=sharing>
>
> [1]
https://mail.google.com/mail/u/0?ui=2&ik=73ebd65ebd&attid=0.1&permmsgid=msg-f:1767388565327924962&th=1887068940754ee2&view=att&disp=inline&realattid=f_libalimc0 <https://mail.google.com/mail/u/0?ui=2&ik=73ebd65ebd&attid=0.1&permmsgid=msg-f:1767388565327924962&th=1887068940754ee2&view=att&disp=inline&realattid=f_libalimc0>
> [2]
https://www.mail-archive.com/virtio-dev@xxxxxxxxxxxxxxxxxxxx/msg12665.html <https://www.mail-archive.com/virtio-dev@xxxxxxxxxxxxxxxxxxxx/msg12665.html>
> [3]
https://github.com/chromeos/virtio-media/blob/main/TRY_IT_OUT.md
<https://github.com/chromeos/virtio-media/blob/main/TRY_IT_OUT.md>
>
> Albert Esteve (1):
> virtio-media: Add virtio media device specification
>
> conformance.tex | 13 +-
> content.tex | 1 +
> device-types/media/description.tex | 574
++++++++++++++++++++++
> device-types/media/device-conformance.tex | 11 +
> device-types/media/driver-conformance.tex | 9 +
> 5 files changed, 604 insertions(+), 4 deletions(-)
> create mode 100644 device-types/media/description.tex
> create mode 100644 device-types/media/device-conformance.tex
> create mode 100644 device-types/media/driver-conformance.tex
>
Kind regards
--
Alexander Gordeev
Senior Software Engineer
OpenSynergy GmbH
Rotherstr. 20, 10245 Berlin
www.opensynergy.com <http://www.opensynergy.com>
--
Alexander Gordeev
Senior Software Engineer
OpenSynergy GmbH
Rotherstr. 20, 10245 Berlin
www.opensynergy.com
