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From: "Németh Márton" <nm127@freemail.hu>
To: Jonathan Corbet <corbet@lwn.net>
Cc: video4linux-list@redhat.com, LKML <linux-kernel@vger.kernel.org>
Subject: cafe_ccic: possible reason why gqcam is not working
Date: Thu, 23 Oct 2008 11:17:39 +0200	[thread overview]
Message-ID: <49004133.7090805@freemail.hu> (raw)

Dear Jonathan,

I read in your documentation found at linux-2.6.27/Documentation/video4linux/cafe_ccic, and
found that you mention that "gqcam" is not working together with cafe_ccic.

I have done some investigation of the gqcam 0.9.1-4 found in Debian system. I wanted
to use gqcam with a different webcam and found out the following things:

 - gqcam currently only supports video4linux 1, and it uses the following
   ioctls: VIDIOCSPICT, VIDIOCSWIN, VIDIOCGCAP, VIDIOCGWIN and VIDIOCGPICT.

 - gqcam only supports read() method of getting the frames.

 - gqcam currently has a limitation that it allocates a static buffer size of
   640*480*3 bytes. This is defined in gqcam.h, struct Camera, field rawbuffer.

As I came across with this buffer limitation, I created a simple patch which at least
can warn the user about this problem instead of getting segmentation fault. The
patch available at http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=502350 .

I hope this helps you to track down why gqcam is not working with cafe_ccic.

Regards,

	Márton Németh

             reply	other threads:[~2008-10-23  9:17 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-23  9:17 Németh Márton [this message]
2008-10-23 14:55 ` cafe_ccic: possible reason why gqcam is not working Jonathan Corbet

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