Hi,

On Tuesday 18 December 2007, Plooij wrote:
> Hi,
>
> I have exactly the same problem as Vidar Normann with the UVC driver:
>
> I have two (identical) UVC cameras. When connecting to one of them and not
> to the other, there is no problem (I can use both of them, but not
> simultaneously). When trying to use them simultaneously, there are two
> cases:
>
> * When they are connected to the same USB host controller, I get the "No
> space left on device" error on the VIDIOC_STREAMON ioctl.

That's because you would use too much USB bandwidth with two video streams.

> * When they are connected to different USB host controllers, one of them
> (/dev/video0) works fine, but the other one (/dev/video1) only gives a
> completely useless corrupted image, containing mostly noise and chunks of
> the first camera's image.

Maybe PCI bandwidth issues ? I'm sorry but I really have no idea there.

> I use the following video format:
> 640x480 YUYV

If possible you should try streaming in MJPEG. That would lower the bandwidth 
requirements.

> I make my own V4L2 software, loosely based on the V4L2 tutorial. I tried to
> reduce the frame rate, but VIDIOC_S_PARM gives EINVAL, so it doesn't seem
> to be supported.

VIDIO_S_PARM should be supported. Maybe the parameters you supplied were 
erroneous ?

Best regards,

Laurent Pinchart
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