From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- Documentation/video4linux/CQcam.txt | 215 ++++++++++++++++++++++++++++++++++++ 1 file changed, 215 insertions(+) create mode 100644 Documentation/video4linux/CQcam.txt (limited to 'Documentation/video4linux/CQcam.txt') diff --git a/Documentation/video4linux/CQcam.txt b/Documentation/video4linux/CQcam.txt new file mode 100644 index 00000000..8977e7ce --- /dev/null +++ b/Documentation/video4linux/CQcam.txt @@ -0,0 +1,215 @@ +c-qcam - Connectix Color QuickCam video4linux kernel driver + +Copyright (C) 1999 Dave Forrest + 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/video/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. I like kmod or kerneld process with the +/etc/modprobe.conf file so the modules can automatically load/unload as +they are used. The video devices could already exist, be generated +using MAKEDEV, or need to be created. 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.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 + +will cause the kmod/modprobe to do certain things. If you are +using kmod, then a request for a 'char-major-81-0' will cause +the 'c-qcam' module to load. If you have other video sources with +modules, you might want to assign the different minor numbers to +different modules. + +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 + + -- cgit v1.2.3