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SubjectRe: v4l interface questions
Date
Pavel Machek wrote:
> Hi!
>
> I have few questions about v4l api.
>
> I have device (vicam == usb 3com homeconnect camera), which would like to
> fit into v4l framework. But... mmap is not really native operation for
> usb. Should I emulate it, or just return unsupported and expect
> applications to use read()?

IHMO applications should be able to fallback to read() if mmap() doesn't
work.

> Similar problem is there with formats. vicam has some really strange
> formats. Should I do conversion in kernel?

Probably. The driver should support at least one of the standard
VIDEO_PALETTE_* formats. It is fine to pick one which comes close to
the native format of the camera, there is no need to support _all_
formats.

> Is there some usermode program that can handle camera without mmap
> ability and can support arbitrary screen sizes + 16bpp grayscale?

8bpp grayscale should be no problem with xawtv. I'd suspect you will
not find any app which can deal with 16bpp, there isn't even a
VIDEO_PALETTE_* #define for this ...

Gerd

--
Damn lot people confuse usability and eye-candy.
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