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Based on kernel version 3.13. Page generated on 2014-01-20 22:04 EST.

1	c-qcam - Connectix Color QuickCam video4linux kernel driver
2	
3	Copyright (C) 1999  Dave Forrest  <drf5n@virginia.edu>
4			    released under GNU GPL.
5	
6	1999-12-08 Dave Forrest, written with kernel version 2.2.12 in mind
7	
8	
9	Table of Contents
10	
11	1.0 Introduction
12	2.0 Compilation, Installation, and Configuration
13	3.0 Troubleshooting
14	4.0 Future Work / current work arounds
15	9.0 Sample Program, v4lgrab
16	10.0 Other Information
17	
18	
19	1.0 Introduction
20	
21	  The file ../../drivers/media/parport/c-qcam.c is a device driver for
22	the Logitech (nee Connectix) parallel port interface color CCD camera.
23	This is a fairly inexpensive device for capturing images.  Logitech
24	does not currently provide information for developers, but many people
25	have engineered several solutions for non-Microsoft use of the Color
26	Quickcam.
27	
28	1.1 Motivation
29	
30	  I spent a number of hours trying to get my camera to work, and I
31	hope this document saves you some time.  My camera will not work with
32	the 2.2.13 kernel as distributed, but with a few patches to the
33	module, I was able to grab some frames. See 4.0, Future Work.
34	
35	
36	
37	2.0 Compilation, Installation, and Configuration
38	
39	  The c-qcam depends on parallel port support, video4linux, and the
40	Color Quickcam.  It is also nice to have the parallel port readback
41	support enabled. I enabled these as modules during the kernel
42	configuration.  The appropriate flags are:
43	
44	    CONFIG_PRINTER       M    for lp.o, parport.o parport_pc.o modules
45	    CONFIG_PNP_PARPORT   M for autoprobe.o IEEE1284 readback module
46	    CONFIG_PRINTER_READBACK M for parport_probe.o IEEE1284 readback module
47	    CONFIG_VIDEO_DEV     M    for videodev.o video4linux module
48	    CONFIG_VIDEO_CQCAM   M    for c-qcam.o  Color Quickcam module
49	
50	  With these flags, the kernel should compile and install the modules.
51	To record and monitor the compilation, I use:
52	
53	 (make zlilo ; \
54	  make modules; \
55	  make modules_install ;
56	  depmod -a ) &>log &
57	 less log  # then a capital 'F' to watch the progress
58	
59	But that is my personal preference.
60	
61	2.2 Configuration
62	
63	  The configuration requires module configuration and device
64	configuration.  The following sections detail these procedures.
65	
66	
67	2.1 Module Configuration
68	
69	  Using modules requires a bit of work to install and pass the
70	parameters.  Understand that entries in /etc/modprobe.d/*.conf of:
71	
72	   alias parport_lowlevel parport_pc
73	   options parport_pc io=0x378 irq=none
74	   alias char-major-81 videodev
75	   alias char-major-81-0 c-qcam
76	
77	2.2 Device Configuration
78	
79	  At this point, we need to ensure that the device files exist.
80	Video4linux used the /dev/video* files, and we want to attach the
81	Quickcam to one of these.
82	
83	   ls -lad /dev/video*  # should produce a list of the video devices
84	
85	If the video devices do not exist, you can create them with:
86	
87	  su
88	  cd /dev
89	  for ii in 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ; do
90	    mknod video$ii c 81 $ii   # char-major-81-[0-16]
91	    chown root.root video$ii  # owned by root
92	    chmod 600 video$ii        # read/writable by root only
93	  done
94	
95	  Lots of people connect video0 to video and bttv, but you might want
96	your c-qcam to mean something more:
97	
98	   ln -s video0 c-qcam  # make /dev/c-qcam a working file
99	   ln -s c-qcam video   # make /dev/c-qcam your default video source
100	
101	  But these are conveniences.  The important part is to make the proper
102	special character files with the right major and minor numbers.  All
103	of the special device files are listed in ../devices.txt.  If you
104	would like the c-qcam readable by non-root users, you will need to
105	change the permissions.
106	
107	3.0 Troubleshooting
108	
109	  If the sample program below, v4lgrab, gives you output then
110	everything is working.
111	
112	    v4lgrab | wc # should give you a count of characters
113	
114	  Otherwise, you have some problem.
115	
116	  The c-qcam is IEEE1284 compatible, so if you are using the proc file
117	system (CONFIG_PROC_FS), the parallel printer support
118	(CONFIG_PRINTER), the IEEE 1284 system,(CONFIG_PRINTER_READBACK), you
119	should be able to read some identification from your quickcam with
120	
121		 modprobe -v parport
122		 modprobe -v parport_probe
123		 cat /proc/parport/PORTNUMBER/autoprobe
124	Returns:
125	  CLASS:MEDIA;
126	  MODEL:Color QuickCam 2.0;
127	  MANUFACTURER:Connectix;
128	
129	  A good response to this indicates that your color quickcam is alive
130	and well.  A common problem is that the current driver does not
131	reliably detect a c-qcam, even though one is attached.  In this case,
132	
133	     modprobe -v c-qcam
134	or
135	     insmod -v c-qcam
136	
137	  Returns a message saying "Device or resource busy"  Development is
138	currently underway, but a workaround is to patch the module to skip
139	the detection code and attach to a defined port.  Check the
140	video4linux mailing list and archive for more current information.
141	
142	3.1 Checklist:
143	
144	  Can you get an image?
145		    v4lgrab >qcam.ppm ; wc qcam.ppm ; xv qcam.ppm
146	
147	  Is a working c-qcam connected to the port?
148		    grep ^ /proc/parport/?/autoprobe
149	
150	  Do the /dev/video* files exist?
151		    ls -lad /dev/video
152	
153	  Is the c-qcam module loaded?
154		    modprobe -v c-qcam ; lsmod
155	
156	  Does the camera work with alternate programs? cqcam, etc?
157	
158	
159	
160	
161	4.0 Future Work / current workarounds
162	
163	  It is hoped that this section will soon become obsolete, but if it
164	isn't, you might try patching the c-qcam module to add a parport=xxx
165	option as in the bw-qcam module so you can specify the parallel port:
166	
167	       insmod -v c-qcam parport=0
168	
169	And bypass the detection code, see ../../drivers/char/c-qcam.c and
170	look for the 'qc_detect' code and call.
171	
172	  Note that there is work in progress to change the video4linux API,
173	this work is documented at the video4linux2 site listed below.
174	
175	
176	9.0 --- A sample program using v4lgrabber,
177	
178	v4lgrab is a simple image grabber that will copy a frame from the
179	first video device, /dev/video0 to standard output in portable pixmap
180	format (.ppm)  To produce .jpg output, you can use it like this:
181	'v4lgrab | convert - c-qcam.jpg'
182	
183	
184	10.0 --- Other Information
185	
186	Use the ../../Maintainers file, particularly the  VIDEO FOR LINUX and PARALLEL
187	PORT SUPPORT sections
188	
189	The video4linux page:
190	  http://linuxtv.org
191	
192	The V4L2 API spec:
193	  http://v4l2spec.bytesex.org/
194	
195	Some web pages about the quickcams:
196	   http://www.pingouin-land.com/howto/QuickCam-HOWTO.html
197	
198	   http://www.crynwr.com/qcpc/            QuickCam Third-Party Drivers
199	   http://www.crynwr.com/qcpc/re.html     Some Reverse Engineering
200	   http://www.wirelesscouch.net/software/gqcam/   v4l client
201	   http://phobos.illtel.denver.co.us/pub/qcread/ doesn't use v4l
202	   ftp://ftp.cs.unm.edu/pub/chris/quickcam/   Has lots of drivers
203	   http://www.cs.duke.edu/~reynolds/quickcam/ Has lots of information
204	
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