HAL: camera

[Matthew Mastracci]

Sean Middleditch wrote:

> is it considered 'bad form' to have multiple capabilities (in different
> namespaces/categories) for the same thing?  hierarchy kinda sucks when
> its overly rigid as it can't express things as they really are, but it
> does avoid a lot of clutter and guesswork.  ("ok, which of the 10 image
> capabilities should I put for this device?")

I'm not an expert on this particular bit of the design, but I believe 
that the core HAL system is designed to expose capabilities at a kernel 
level only.  It's up to other user-space devices to expose additional, 
richer capabilities themselves.

For instance, gphoto might take:
camera
camera.image
camera.movie
multimedia.video
etc...

and create a gphoto.image capability with some sort of reference for 
gphoto aware apps.  It would be up to gphoto to determine how to get a 
still image from a camera, scanner or v4l device.  When you want to use 
a gphoto device, you'd pass it the HAL device path, it would look up the 
object and automatically figure out how to provide you with a still image.

Matt.