[Spice-devel] [PATCH v3 1/2] virtio-video: Add virtio video device specification

[Keiichi Watanabe]

Hi everyone,

I have implemented a virtio-video device following my v3 spec in
crosvm, which worked well together with Dmitry's driver [1]. I've
started preparing v4 proposal to address problems found while
implementing the driver and the devices.

Regarding v3 protocol, I'm thinking about how we can differentiate
'parameters' and 'controls' in the virtio-video spec?
In the previous discussion, we decided to have a profile, level and
bitrate as controls because we want to query supported values for each
field.
But, I don't think it's a good criteria because it'd be possible to
query other values in params.

So, I'm thinking about what should be the difference between params
and controls. If no difference, we should deprecate
virtio_video_params and have every field there as a control value
instead.
If we add a new command to get and set multiple controls at once, this
change won't cause overhead.

What do you think? Is there anything I missed?
If it sounds fine, I'll remove virtio_video_params from the v4 spec proposal.

Best regards,
Keiichi

[1]: https://patchwork.linuxtv.org/patch/61717/