mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-19 02:04:19 +08:00
83c735379b
due to structure change for video drivers, change the description with correct path. Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com> Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
206 lines
6.4 KiB
Plaintext
206 lines
6.4 KiB
Plaintext
c-qcam - Connectix Color QuickCam video4linux kernel driver
|
|
|
|
Copyright (C) 1999 Dave Forrest <drf5n@virginia.edu>
|
|
released under GNU GPL.
|
|
|
|
1999-12-08 Dave Forrest, written with kernel version 2.2.12 in mind
|
|
|
|
|
|
Table of Contents
|
|
|
|
1.0 Introduction
|
|
2.0 Compilation, Installation, and Configuration
|
|
3.0 Troubleshooting
|
|
4.0 Future Work / current work arounds
|
|
9.0 Sample Program, v4lgrab
|
|
10.0 Other Information
|
|
|
|
|
|
1.0 Introduction
|
|
|
|
The file ../../drivers/media/parport/c-qcam.c is a device driver for
|
|
the Logitech (nee Connectix) parallel port interface color CCD camera.
|
|
This is a fairly inexpensive device for capturing images. Logitech
|
|
does not currently provide information for developers, but many people
|
|
have engineered several solutions for non-Microsoft use of the Color
|
|
Quickcam.
|
|
|
|
1.1 Motivation
|
|
|
|
I spent a number of hours trying to get my camera to work, and I
|
|
hope this document saves you some time. My camera will not work with
|
|
the 2.2.13 kernel as distributed, but with a few patches to the
|
|
module, I was able to grab some frames. See 4.0, Future Work.
|
|
|
|
|
|
|
|
2.0 Compilation, Installation, and Configuration
|
|
|
|
The c-qcam depends on parallel port support, video4linux, and the
|
|
Color Quickcam. It is also nice to have the parallel port readback
|
|
support enabled. I enabled these as modules during the kernel
|
|
configuration. The appropriate flags are:
|
|
|
|
CONFIG_PRINTER M for lp.o, parport.o parport_pc.o modules
|
|
CONFIG_PNP_PARPORT M for autoprobe.o IEEE1284 readback module
|
|
CONFIG_PRINTER_READBACK M for parport_probe.o IEEE1284 readback module
|
|
CONFIG_VIDEO_DEV M for videodev.o video4linux module
|
|
CONFIG_VIDEO_CQCAM M for c-qcam.o Color Quickcam module
|
|
|
|
With these flags, the kernel should compile and install the modules.
|
|
To record and monitor the compilation, I use:
|
|
|
|
(make zlilo ; \
|
|
make modules; \
|
|
make modules_install ;
|
|
depmod -a ) &>log &
|
|
less log # then a capital 'F' to watch the progress
|
|
|
|
But that is my personal preference.
|
|
|
|
2.2 Configuration
|
|
|
|
The configuration requires module configuration and device
|
|
configuration. The following sections detail these procedures.
|
|
|
|
|
|
2.1 Module Configuration
|
|
|
|
Using modules requires a bit of work to install and pass the
|
|
parameters. Understand that entries in /etc/modprobe.d/*.conf of:
|
|
|
|
alias parport_lowlevel parport_pc
|
|
options parport_pc io=0x378 irq=none
|
|
alias char-major-81 videodev
|
|
alias char-major-81-0 c-qcam
|
|
|
|
2.2 Device Configuration
|
|
|
|
At this point, we need to ensure that the device files exist.
|
|
Video4linux used the /dev/video* files, and we want to attach the
|
|
Quickcam to one of these.
|
|
|
|
ls -lad /dev/video* # should produce a list of the video devices
|
|
|
|
If the video devices do not exist, you can create them with:
|
|
|
|
su
|
|
cd /dev
|
|
for ii in 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ; do
|
|
mknod video$ii c 81 $ii # char-major-81-[0-16]
|
|
chown root.root video$ii # owned by root
|
|
chmod 600 video$ii # read/writable by root only
|
|
done
|
|
|
|
Lots of people connect video0 to video and bttv, but you might want
|
|
your c-qcam to mean something more:
|
|
|
|
ln -s video0 c-qcam # make /dev/c-qcam a working file
|
|
ln -s c-qcam video # make /dev/c-qcam your default video source
|
|
|
|
But these are conveniences. The important part is to make the proper
|
|
special character files with the right major and minor numbers. All
|
|
of the special device files are listed in ../devices.txt. If you
|
|
would like the c-qcam readable by non-root users, you will need to
|
|
change the permissions.
|
|
|
|
3.0 Troubleshooting
|
|
|
|
If the sample program below, v4lgrab, gives you output then
|
|
everything is working.
|
|
|
|
v4lgrab | wc # should give you a count of characters
|
|
|
|
Otherwise, you have some problem.
|
|
|
|
The c-qcam is IEEE1284 compatible, so if you are using the proc file
|
|
system (CONFIG_PROC_FS), the parallel printer support
|
|
(CONFIG_PRINTER), the IEEE 1284 system,(CONFIG_PRINTER_READBACK), you
|
|
should be able to read some identification from your quickcam with
|
|
|
|
modprobe -v parport
|
|
modprobe -v parport_probe
|
|
cat /proc/parport/PORTNUMBER/autoprobe
|
|
Returns:
|
|
CLASS:MEDIA;
|
|
MODEL:Color QuickCam 2.0;
|
|
MANUFACTURER:Connectix;
|
|
|
|
A good response to this indicates that your color quickcam is alive
|
|
and well. A common problem is that the current driver does not
|
|
reliably detect a c-qcam, even though one is attached. In this case,
|
|
|
|
modprobe -v c-qcam
|
|
or
|
|
insmod -v c-qcam
|
|
|
|
Returns a message saying "Device or resource busy" Development is
|
|
currently underway, but a workaround is to patch the module to skip
|
|
the detection code and attach to a defined port. Check the
|
|
video4linux mailing list and archive for more current information.
|
|
|
|
3.1 Checklist:
|
|
|
|
Can you get an image?
|
|
v4lgrab >qcam.ppm ; wc qcam.ppm ; xv qcam.ppm
|
|
|
|
Is a working c-qcam connected to the port?
|
|
grep ^ /proc/parport/?/autoprobe
|
|
|
|
Do the /dev/video* files exist?
|
|
ls -lad /dev/video
|
|
|
|
Is the c-qcam module loaded?
|
|
modprobe -v c-qcam ; lsmod
|
|
|
|
Does the camera work with alternate programs? cqcam, etc?
|
|
|
|
|
|
|
|
|
|
4.0 Future Work / current workarounds
|
|
|
|
It is hoped that this section will soon become obsolete, but if it
|
|
isn't, you might try patching the c-qcam module to add a parport=xxx
|
|
option as in the bw-qcam module so you can specify the parallel port:
|
|
|
|
insmod -v c-qcam parport=0
|
|
|
|
And bypass the detection code, see ../../drivers/char/c-qcam.c and
|
|
look for the 'qc_detect' code and call.
|
|
|
|
Note that there is work in progress to change the video4linux API,
|
|
this work is documented at the video4linux2 site listed below.
|
|
|
|
|
|
9.0 --- A sample program using v4lgrabber,
|
|
|
|
v4lgrab is a simple image grabber that will copy a frame from the
|
|
first video device, /dev/video0 to standard output in portable pixmap
|
|
format (.ppm) To produce .jpg output, you can use it like this:
|
|
'v4lgrab | convert - c-qcam.jpg'
|
|
|
|
|
|
10.0 --- Other Information
|
|
|
|
Use the ../../Maintainers file, particularly the VIDEO FOR LINUX and PARALLEL
|
|
PORT SUPPORT sections
|
|
|
|
The video4linux page:
|
|
http://linuxtv.org
|
|
|
|
The V4L2 API spec:
|
|
http://v4l2spec.bytesex.org/
|
|
|
|
Some web pages about the quickcams:
|
|
http://www.pingouin-land.com/howto/QuickCam-HOWTO.html
|
|
|
|
http://www.crynwr.com/qcpc/ QuickCam Third-Party Drivers
|
|
http://www.crynwr.com/qcpc/re.html Some Reverse Engineering
|
|
http://www.wirelesscouch.net/software/gqcam/ v4l client
|
|
http://phobos.illtel.denver.co.us/pub/qcread/ doesn't use v4l
|
|
ftp://ftp.cs.unm.edu/pub/chris/quickcam/ Has lots of drivers
|
|
http://www.cs.duke.edu/~reynolds/quickcam/ Has lots of information
|
|
|
|
|