Hi Mauro,

On Thursday 25 August 2011 14:43:56 Mauro Carvalho Chehab wrote:

Em 24-08-2011 19:29, Sakari Ailus escreveu:

[snip]

quoted

The question I still have on this is that how should the user know which
video node to access on an embedded system with a camera: the OMAP 3 ISP,
for example, contains some eight video nodes which have different ISP
blocks connected to them. Likely two of these nodes are useful for a
general purpose application based on which image format it requests. It
would make sense to provide generic applications information only on
those devices they may meaningfully use.

IMO, we should create a namespace device mapping for video devices. What I
mean is that we should keep the "raw" V4L2 devices as:
	/dev/video??
But also recommend the creation of a new userspace map, like:
	/dev/webcam??
	/dev/tv??
	...
with is an alias for the actual device.

Something similar to dvd/cdrom aliases that already happen on most distros:

lrwxrwxrwx   1 root root           3 Ago 24 12:14 cdrom -> sr0
lrwxrwxrwx   1 root root           3 Ago 24 12:14 cdrw -> sr0
lrwxrwxrwx   1 root root           3 Ago 24 12:14 dvd -> sr0
lrwxrwxrwx   1 root root           3 Ago 24 12:14 dvdrw -> sr0

I've been toying with a similar idea. libv4l currently wraps /dev/video* 
device nodes and assumes a 1:1 relationship between a video device node and a 
video device. Should this assumption be somehow removed, replaced by a video 
device concept that wouldn't be tied to a single video device node ?

-- 
Regards,

Laurent Pinchart