Hi Basil,
On Saturday 13 March 2010 02:55:47 Basil Mohamed Gohar wrote:
> I originally posted this to the video4linux mailing list, but I've since
> discovered that this is the appropriate place (or so I understand) for
> video4linux questions. My question is how can I capture the raw JPEG
> image stream (e.g., MJPEG) from my webcam, which reports through v4l2
> that it is capable of. I am using the gst-launch cli to gstreamer,
>
> which confirms that my webcam has this capability:
> > image/jpeg, width=(int)640, height=(int)480, framerate=(fraction){
> > 30/1, 25/1, 20/1, 15/1, 10/1, 5/1 }
>
> And, indeed, I can capture using this capability, but the framerate is
> not at the specified rate, but at a much lower value (half or less).
> So, even if I specify 30fps, I get something less. I can capture the
> full 30fps when I use one of the yuv modes, though, so it's clearly
> capable of delivering that framerate.
>
> My webcam is a Logitech QuickCam Pro 5000. The lsusb output is:
> > 046d:08ce Logitech, Inc. QuickCam Pro 5000
>
> An example command line I try is as follows:
> > gst-launch-0.10 v4l2src device=/dev/video0 ! 'image/jpeg, width=640,
> > height=480, framerate=30/1' ! jpegdec ! xvimagesink
Have you tried disabling auto-exposure ? The camera is allowed to reduce the
frame rate in low-light conditions if auto-exposure is turned on.
--
Regards,
Laurent Pinchart
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