From: Uwe Sauter <uwe.sauter@yahoo.de>
To: linux-media@vger.kernel.org
Subject: libv4lconvert & Logitech Webcam 9000 Pro
Date: Wed, 07 Jul 2010 17:53:24 +0200 [thread overview]
Message-ID: <4C34A2F4.8030307@yahoo.de> (raw)
Hi everybody,
I have a problem concerning libv4lconvert, Logitech Webcam 9000 Pro and
perhaps OpenCV.
When I try to run OpenCV's examples that access the webcam they crash
with the following:
--------------------
libv4lconvert: warning more framesizes then I can handle!
libv4lconvert: warning more framesizes then I can handle!
VIDIOC_QUERYCTRL: Input/output error
mmap: Invalid argument
munmap: Invalid argument
munmap: Invalid argument
munmap: Invalid argument
munmap: Invalid argument
Unable to stop the stream.: Bad file descriptor
munmap: Invalid argument
munmap: Invalid argument
munmap: Invalid argument
munmap: Invalid argument
libv4lconvert: warning more framesizes then I can handle!
libv4lconvert: warning more framesizes then I can handle!
HIGHGUI ERROR: V4L: device /dev/video0: Unable to query number of channels
--------------------
It seems to me that the cam has more framesizes than libv4lconvert
actually can handle.This error happens on verions 0.6.1, 0.7.91 and
0.8.0. A quick fix to this:
change in v4l-utils-<version>/lib/libv4lconvert/libv4lconvert-priv.h:
line 32: #define V4LCONVERT_MAX_FRAMESIZES 16
to: #define V4LCONVERT_MAX_FRAMESIZES 32
or any other higher number.
I have no idea which implications result from this.
The mmap/munmap/stream/HIGHGUI errors seem to be OpenCV related.
guvcview/luvcview both work BUT they don't link agains libv4lconvert.
I hope you can include this. If I can help testing I'm glad to
participate. If you need more infos regarding the cam feel free to ask.
Thank you,
Uwe Sauter
reply other threads:[~2010-07-07 16:00 UTC|newest]
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