Re: [Linux-uvc-devel] Test of the driver on GNU/Debian amd64

[<Oli...@id...>]

Hello,

On Wed, Jan 04, 2006 at 06:56:15PM +0100, Laurent Pinchart wrote:
> > OpenCV is now working with the uvc driver. I have implemented support of
> > V4L2_PIX_FMT_YUYV in OpenCV. Feel free to checkout the CVS of OpenCV if
> > you want to try it.
> 
> Good work. While you're at it, you can also implement MJPEG support ;-) I 
> recently posted a patch to the video4linux and qt-interest mailing lists to 
> add MJPEG support to Qt, it can be used as a starting point.

Thanks for the tip. OpenCV is now supporting MJPEG. :-)
So, now with OpenCV (and the UVC driver), you can:
  - load a image file of format MJPEG,
  - use V4L2_PIX_FMT_MJPEG format for video acquisition.

The patch you have posted to the video4linux mailing list was helpful.

> > I don't know why, but it seems changing the size of the capture don't
> > works. I always have a capture of 1024x576 pixels. Even if I try to set
> > to another size, like for example 640x480. This must be a problem with
> > OpenCV, as it seems your test program is changing the resolution
> > correctly (altough I don't have look at the output files, because I
> > don't know how to display yuyv raw data images...).
> 
> That's normal. The minimum size for YUYV capture is 1024x576. Lower 
> resolutions are only available in MJPEG. I'll ask Logitech if they can enable 
> YUYV in lower resolutions in their firmware updates.

With V4L2_PIX_FMT_MJPEG, resolution switching works. Cool. :-)

Thanks for your suggestions.

        Olivier
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