video4linux devices

[Kay Sievers]

On Fri, Jan 13, 2006 at 07:20:35PM +0000, Richard Hughes wrote:
> On Fri, 2006-01-13 at 20:09 +0100, Kay Sievers wrote:
> > On Fri, Jan 13, 2006 at 06:35:17PM +0000, Richard Hughes wrote:

> I think we need to get the application designers involved here.
> 
> > > Does this mean we have to add properties from an fdi file, or query the
> > > device with a prober using the V4L calls?
> > 
> > In the 0.4 HAL I used ioctls to query information from the video device.
> > There have been may changes to the v4l layer in the meantime and the
> > version1 interface is deprecated if I remember correctly, but as said, I
> > have almost no clue about video. :)
> 
> I think you are correct with v1 ioctls being depreciated, but I'm sure a
> prober using v4l2 ioctls could provide a wealth of information about a
> device.

Sure, I meant that the v4l1 version is deprecated, not the ioctls.

> Most of the posts on pwc at lists.saillard.org (which I'm subscribed) seem
> to be about querying properties for webcams, for example resolutions and
> colour depths supported. This would be a big win for a lot of users.
> 
> I'm sure the gstreamer guys know quite a bit about devices and v4l2. Can
> one of you guys write about this in your blog, and we could get some
> interest from interested parties.

Well, if you like to ask on their mailing list that would be great. I don't
even have any hardware besides a really old ov511 chip webcam. It's a bit of
moderation work, that's probably needed to find out what information they
think HAL should provide or think how devices could be put in categories.

I remember some discussion with a DVB guy we had in the early days, that
ended pretty complicated. But that was at a time we didn't have stringlists
and such stuff, so it may be easier today. :)

Kay