Messages in this thread | | | From | Gerd Knorr <> | Subject | Re: v4l interface questions | Date | 28 Aug 2001 07:14:12 GMT |
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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
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