faq

在Linux下用于webeye的摄像头的驱动

(Note: this FAQ is quickly composed and contains poor editing.
 If you'd like to improve it, send patches to me/qce-ga-devel list)

Q: I get the following error message:
   qc-driver.c:51: linux/version.h: No such file or directory
   qc-driver.c:52: parse error
   or
   .../include/linux/config.h:4: linux/autoconf.h: No such file or directory
   or
   sed: can't read /usr/src/linux/Makefile: No such file or directory
   or
   Makefile:26: /usr/src/linux/.config: No such file or directory
A: You must install Linux kernel source code corresponding
   to the kernel you will be running with the camera driver.
   The source must be configured and depencies must have been
   created. Typically you can just install the kernel source
   package that comes with your distribution. If you're instead using
   virgin kernel in /usr/src/linux-x.y.zz, you must first copy
   kernel configuration file to /usr/src/linux-x.y.zz/.config,
   then go to the directory and run "make oldconfig" and "make dep".
   You may also need to type
        cd /usr/src/linux-x.y.zz
        make include/linux/version.h
   This should create the missing linux/version.h file.
   Some more help for Redhat/Mandrake users:

   If you get a lot of errors on mandrake or red hat when 
   you do a make, it may be because you didn't install a 
   full development version, meaning your kernel sources 
   are not there. 
   This worked for me 

   urpmi kernel-source 
   urpmi kernel-headers 
   urpmi kernel-doc 

   urpmi is your friend, it will find the CD that it needs 
   to get this. Some rpms may be installed already, big 
   deal, do this then do a make, it worked on mandrake 8.2! 

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Q: And finally, I look for /dev/video* (to set the videodev on
   gnomemeeting) and I haven't any videodevice.
A:
	mknod /dev/video0 c 81 0
	chmod a+r /dev/video0
	ln -s /dev/video0 /dev/video

------------------------------------------------------------
Q: quickcam.c:2099: too few arguments to function `remap_page_range_R2baf18f2'
   Damian Ivereigh posted a patch to be able to compile
   the driver for RedHat 9.0 but I don't know how to do
A: Due to qc-usb 0.5.1, this should be now fixed. If you
   still encounter this problem, and
   if you're using qc-usb, just compile it with command
	USER_OPT=-DHAVE_VMA=1 make all
   Otherwise (if you're using older qce-ga):
1. Download qce-ga-0.40d.tar.gz package and save
   the patch
	wget http://www.ee.oulu.fi/~tuukkat/quickcam/qce-gq-rh9.patch
	wget http://www.ee.oulu.fi/~tuukkat/quickcam/qce-ga-0.40d.tar.gz
2. Extract the package:
	tar xvfz qce-ga-0.40d.tar.gz
3. Enter the source directory
        cd qce-ga-0.40d
4. Apply the patch:
	patch -s -p1 < ../qce-gq-rh9.patch
5. patch complains that the patch is reversed. Answer yes:
Reversed (or previously applied) patch detected!  Assume -R? [n] y
6. Then compile and install the driver normally
	make
	./quickcam.sh

------------------------------------------------------------
Q: I don't have permissions for /dev/video?
A: Easiest way to add permissions is to do
	chmod a+rw /dev/video?
   as root. Altenatively, especially on Debian, users belonging
   to the "video" group can access video devices. In this case,
   you might instead prefer issuing
	addgroup <yourlogin> video
   as root and then login as normal user. Check in which groups
   your are in with
	id -a

------------------------------------------------------------
Q: My log files keep filling up (but the driver works fine)!
A: use "qcset debug=0" to disable all possible messages.
   If it doesn't help, send e-mail to mailing lists showing
   the exact error message that fills your logs.
   (especially "frame lost" message is uninteresting, it is
   known to happen with some programs and will be fixed later.

------------------------------------------------------------
Q: quickcam.o: kernel-module version mismatch
      quickcam.o was compiled for kernel version 2.4.18
      while this kernel is version 2.4.18-686-smp.   
A: Then edit "Makefile" in the kernel source directory and change the line 4
   from
   	EXTRAVERSION =
   to
   	EXTRAVERSION = -686-smp
   --or if this doesn't help--
   Go to /usr/src/linux-2.4/include/linux/version.h and change the
   UTS_RELEASE to match the output of "uname -r" on the command line
   (should be 2.4.18-686-smp). Then recompile the module and then the
   insmod will work perfectly :) [from Mark]

------------------------------------------------------------
Q: I want to reverse engineer an USB camera. How?
A: Run *ugh* Windoze *cough* drivers with a USB stream
   capture program, like http://sourceforge.net/projects/usbsnoop/
   Then send the same commands to the camera from Linux.

------------------------------------------------------------
Q: I added IEEE1394 card and now QuickCam doesn't work?
A: The card driver overwrites /dev/video0..2, use
   insmod ./quickcam.o video_nr=3
   and then /dev/video3 with QuickCam.
   Create /dev/video3 with mknod if necessary.
   [from Makarand]

------------------------------------------------------------
Q: I get oops after call path video_open/qc_v4l_open/qc_v4l_init/
   qc_capt_init/qc_frame_init/qc_sensor_init/hdcs_init
   because qc->sensor pointer was poisoned with 0x5B?
A: Some of the driver objects were compiled with debugging
   and some without. If you change any options (LINUX_DIR or
   USER_OPT) you must always do first "make clean"!

------------------------------------------------------------
Q: Can I use more than one camera simultaneously?
A: Yes, if you have enough bandwidth in USB bus. A single
   USB 1.0 bus can drive generally only one camera (there is
   a report that with using "qcset subsample=y" even two
   cameras might work in one bus, in theory it shouldn't).
   If you have just two USB ports in your computer, it
   typically means that you have just one USB bus.
   You can attach the camera into the ports and do
   "cat /proc/video/quickcam/*" to see whether the USB bus
   number is different or the same in the two ports.
   A single USB 2.0 bus may or may not work with multiple
   cameras. It appears to depend on the vendor.

------------------------------------------------------------
Q: Do I need to patch my kernel with linux-xxx-quickcam.patch?
A: No. To be more precise, only if you want to compile the
   driver statically into the kernel which would be useful
   usually only if you want to boot Linux from the camera ;)
   or if you otherwise want to include the camera driver
   into the kernel source. If you really want to do this,
   use "make patch", but it will work only with some kernel
   versions.