+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 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.
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?
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 PDF with the media section only: 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 [2] https://www.mail-archive.com/virtio-dev@xxxxxxxxxxxxxxxxxxxx/msg12665.html [3] 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
