Re: [V4L2] EV control API for digital camera

[Dongsoo Kim <dongsoo45.kim@samsung.com>]

On 화, 2009-02-03 at 11:20 +0100, Laurent Pinchart wrote:
> Hi Nate,
> 
> On Thursday 29 January 2009, Dongsoo Kim wrote:
> > Thank you.
> >
> > So if V4L2_CID_EXPOSURE is for Exposure Value control, I think there
> > is no api for exposure metering. right?
> 
> V4L2_CID_EXPOSURE controls the exposure time. This is often implemented 
> through a mechanical or electronic shutter in the device.
> 
> What kind of exposure metering do you have in mind ? Can you give us some 
> details ?

I mean photometry which is all about light meter (or exposure meter).
Like spot metering, center weighted things..

> 
> > Actually many of APIs for camera are missing I guess.
> 
> You're probably right. The V4L1/V4L2 API have been developed for frame 
> grabbers and extended to webcams. Now that high-end digital cameras get USB 
> connectivity, the V4L2 API should be extended with new controls. Feel free to 
> submit proposals for discussion on the linux-media mailing list.
> 
Thank you for you encouraging words.
Actually I'm working on some ISP devices from NEC, Fujitsu. and ARM SOC
camera interface peripheral like PXA3, S3C64XX, OMAP3..
I wish I could make a device very close to a real digital camera.
It wouldn't take so long until I submit a RFC about V4L2 API for digital
camera :) (I hope so at least)
Cheers.

Regards,
Nate