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Linus Torvalds1da177e2005-04-16 15:20:36 -07001c-qcam - Connectix Color QuickCam video4linux kernel driver
2
3Copyright (C) 1999 Dave Forrest <drf5n@virginia.edu>
4 released under GNU GPL.
5
61999-12-08 Dave Forrest, written with kernel version 2.2.12 in mind
7
8
9Table of Contents
10
111.0 Introduction
122.0 Compilation, Installation, and Configuration
133.0 Troubleshooting
144.0 Future Work / current work arounds
159.0 Sample Program, v4lgrab
1610.0 Other Information
17
18
191.0 Introduction
20
21 The file ../drivers/char/c-qcam.c is a device driver for the
22Logitech (nee Connectix) parallel port interface color CCD camera.
23This is a fairly inexpensive device for capturing images. Logitech
24does not currently provide information for developers, but many people
25have engineered several solutions for non-Microsoft use of the Color
26Quickcam.
27
281.1 Motivation
29
30 I spent a number of hours trying to get my camera to work, and I
31hope this document saves you some time. My camera will not work with
32the 2.2.13 kernel as distributed, but with a few patches to the
33module, I was able to grab some frames. See 4.0, Future Work.
34
35
36
372.0 Compilation, Installation, and Configuration
38
39 The c-qcam depends on parallel port support, video4linux, and the
40Color Quickcam. It is also nice to have the parallel port readback
41support enabled. I enabled these as modules during the kernel
42configuration. 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.
51To 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
59But that is my personal preference.
60
612.2 Configuration
62
63 The configuration requires module configuration and device
64configuration. I like kmod or kerneld process with the
65/etc/modprobe.conf file so the modules can automatically load/unload as
66they are used. The video devices could already exist, be generated
67using MAKEDEV, or need to be created. The following sections detail
68these procedures.
69
70
712.1 Module Configuration
72
73 Using modules requires a bit of work to install and pass the
74parameters. Understand that entries in /etc/modprobe.conf of:
75
76 alias parport_lowlevel parport_pc
77 options parport_pc io=0x378 irq=none
78 alias char-major-81 videodev
79 alias char-major-81-0 c-qcam
80
81will cause the kmod/modprobe to do certain things. If you are
82using kmod, then a request for a 'char-major-81-0' will cause
83the 'c-qcam' module to load. If you have other video sources with
84modules, you might want to assign the different minor numbers to
85different modules.
86
872.2 Device Configuration
88
89 At this point, we need to ensure that the device files exist.
90Video4linux used the /dev/video* files, and we want to attach the
91Quickcam to one of these.
92
93 ls -lad /dev/video* # should produce a list of the video devices
94
95If the video devices do not exist, you can create them with:
96
97 su
98 cd /dev
99 for ii in 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ; do
100 mknod video$ii c 81 $ii # char-major-81-[0-16]
101 chown root.root video$ii # owned by root
102 chmod 600 video$ii # read/writable by root only
103 done
104
105 Lots of people connect video0 to video and bttv, but you might want
106your c-qcam to mean something more:
107
108 ln -s video0 c-qcam # make /dev/c-qcam a working file
109 ln -s c-qcam video # make /dev/c-qcam your default video source
110
111 But these are conveniences. The important part is to make the proper
112special character files with the right major and minor numbers. All
113of the special device files are listed in ../devices.txt. If you
114would like the c-qcam readable by non-root users, you will need to
115change the permissions.
116
1173.0 Troubleshooting
118
119 If the sample program below, v4lgrab, gives you output then
120everything is working.
121
122 v4lgrab | wc # should give you a count of characters
123
124 Otherwise, you have some problem.
125
126 The c-qcam is IEEE1284 compatible, so if you are using the proc file
127system (CONFIG_PROC_FS), the parallel printer support
128(CONFIG_PRINTER), the IEEE 1284 system,(CONFIG_PRINTER_READBACK), you
129should be able to read some identification from your quickcam with
130
131 modprobe -v parport
132 modprobe -v parport_probe
133 cat /proc/parport/PORTNUMBER/autoprobe
134Returns:
135 CLASS:MEDIA;
136 MODEL:Color QuickCam 2.0;
137 MANUFACTURER:Connectix;
138
139 A good response to this indicates that your color quickcam is alive
140and well. A common problem is that the current driver does not
141reliably detect a c-qcam, even though one is attached. In this case,
142
143 modprobe -v c-qcam
144or
145 insmod -v c-qcam
146
147 Returns a message saying "Device or resource busy" Development is
148currently underway, but a workaround is to patch the module to skip
149the detection code and attach to a defined port. Check the
150video4linux mailing list and archive for more current information.
151
1523.1 Checklist:
153
154 Can you get an image?
155 v4lgrab >qcam.ppm ; wc qcam.ppm ; xv qcam.ppm
156
157 Is a working c-qcam connected to the port?
158 grep ^ /proc/parport/?/autoprobe
159
160 Do the /dev/video* files exist?
161 ls -lad /dev/video
162
163 Is the c-qcam module loaded?
164 modprobe -v c-qcam ; lsmod
165
166 Does the camera work with alternate programs? cqcam, etc?
167
168
169
170
1714.0 Future Work / current workarounds
172
173 It is hoped that this section will soon become obsolete, but if it
174isn't, you might try patching the c-qcam module to add a parport=xxx
175option as in the bw-qcam module so you can specify the parallel port:
176
177 insmod -v c-qcam parport=0
178
179And bypass the detection code, see ../../drivers/char/c-qcam.c and
180look for the 'qc_detect' code and call.
181
182 Note that there is work in progress to change the video4linux API,
183this work is documented at the video4linux2 site listed below.
184
185
1869.0 --- A sample program using v4lgrabber,
187
188This program is a simple image grabber that will copy a frame from the
189first video device, /dev/video0 to standard output in portable pixmap
190format (.ppm) Using this like: 'v4lgrab | convert - c-qcam.jpg'
191produced this picture of me at
192 http://mug.sys.virginia.edu/~drf5n/extras/c-qcam.jpg
193
194-------------------- 8< ---------------- 8< -----------------------------
195
196/* Simple Video4Linux image grabber. */
197/*
198 * Video4Linux Driver Test/Example Framegrabbing Program
199 *
200 * Compile with:
201 * gcc -s -Wall -Wstrict-prototypes v4lgrab.c -o v4lgrab
202 * Use as:
203 * v4lgrab >image.ppm
204 *
205 * Copyright (C) 1998-05-03, Phil Blundell <philb@gnu.org>
206 * Copied from http://www.tazenda.demon.co.uk/phil/vgrabber.c
207 * with minor modifications (Dave Forrest, drf5n@virginia.edu).
208 *
209 */
210
211#include <unistd.h>
212#include <sys/types.h>
213#include <sys/stat.h>
214#include <fcntl.h>
215#include <stdio.h>
216#include <sys/ioctl.h>
217#include <stdlib.h>
218
219#include <linux/types.h>
220#include <linux/videodev.h>
221
222#define FILE "/dev/video0"
223
224/* Stole this from tvset.c */
225
226#define READ_VIDEO_PIXEL(buf, format, depth, r, g, b) \
227{ \
228 switch (format) \
229 { \
230 case VIDEO_PALETTE_GREY: \
231 switch (depth) \
232 { \
233 case 4: \
234 case 6: \
235 case 8: \
236 (r) = (g) = (b) = (*buf++ << 8);\
237 break; \
238 \
239 case 16: \
240 (r) = (g) = (b) = \
241 *((unsigned short *) buf); \
242 buf += 2; \
243 break; \
244 } \
245 break; \
246 \
247 \
248 case VIDEO_PALETTE_RGB565: \
249 { \
250 unsigned short tmp = *(unsigned short *)buf; \
251 (r) = tmp&0xF800; \
252 (g) = (tmp<<5)&0xFC00; \
253 (b) = (tmp<<11)&0xF800; \
254 buf += 2; \
255 } \
256 break; \
257 \
258 case VIDEO_PALETTE_RGB555: \
259 (r) = (buf[0]&0xF8)<<8; \
260 (g) = ((buf[0] << 5 | buf[1] >> 3)&0xF8)<<8; \
261 (b) = ((buf[1] << 2 ) & 0xF8)<<8; \
262 buf += 2; \
263 break; \
264 \
265 case VIDEO_PALETTE_RGB24: \
266 (r) = buf[0] << 8; (g) = buf[1] << 8; \
267 (b) = buf[2] << 8; \
268 buf += 3; \
269 break; \
270 \
271 default: \
272 fprintf(stderr, \
273 "Format %d not yet supported\n", \
274 format); \
275 } \
276}
277
278int get_brightness_adj(unsigned char *image, long size, int *brightness) {
279 long i, tot = 0;
280 for (i=0;i<size*3;i++)
281 tot += image[i];
282 *brightness = (128 - tot/(size*3))/3;
283 return !((tot/(size*3)) >= 126 && (tot/(size*3)) <= 130);
284}
285
286int main(int argc, char ** argv)
287{
288 int fd = open(FILE, O_RDONLY), f;
289 struct video_capability cap;
290 struct video_window win;
291 struct video_picture vpic;
292
293 unsigned char *buffer, *src;
294 int bpp = 24, r, g, b;
295 unsigned int i, src_depth;
296
297 if (fd < 0) {
298 perror(FILE);
299 exit(1);
300 }
301
302 if (ioctl(fd, VIDIOCGCAP, &cap) < 0) {
303 perror("VIDIOGCAP");
304 fprintf(stderr, "(" FILE " not a video4linux device?)\n");
305 close(fd);
306 exit(1);
307 }
308
309 if (ioctl(fd, VIDIOCGWIN, &win) < 0) {
310 perror("VIDIOCGWIN");
311 close(fd);
312 exit(1);
313 }
314
315 if (ioctl(fd, VIDIOCGPICT, &vpic) < 0) {
316 perror("VIDIOCGPICT");
317 close(fd);
318 exit(1);
319 }
320
321 if (cap.type & VID_TYPE_MONOCHROME) {
322 vpic.depth=8;
323 vpic.palette=VIDEO_PALETTE_GREY; /* 8bit grey */
324 if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) {
325 vpic.depth=6;
326 if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) {
327 vpic.depth=4;
328 if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) {
329 fprintf(stderr, "Unable to find a supported capture format.\n");
330 close(fd);
331 exit(1);
332 }
333 }
334 }
335 } else {
336 vpic.depth=24;
337 vpic.palette=VIDEO_PALETTE_RGB24;
338
339 if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) {
340 vpic.palette=VIDEO_PALETTE_RGB565;
341 vpic.depth=16;
342
343 if(ioctl(fd, VIDIOCSPICT, &vpic)==-1) {
344 vpic.palette=VIDEO_PALETTE_RGB555;
345 vpic.depth=15;
346
347 if(ioctl(fd, VIDIOCSPICT, &vpic)==-1) {
348 fprintf(stderr, "Unable to find a supported capture format.\n");
349 return -1;
350 }
351 }
352 }
353 }
354
355 buffer = malloc(win.width * win.height * bpp);
356 if (!buffer) {
357 fprintf(stderr, "Out of memory.\n");
358 exit(1);
359 }
360
361 do {
362 int newbright;
363 read(fd, buffer, win.width * win.height * bpp);
364 f = get_brightness_adj(buffer, win.width * win.height, &newbright);
365 if (f) {
366 vpic.brightness += (newbright << 8);
367 if(ioctl(fd, VIDIOCSPICT, &vpic)==-1) {
368 perror("VIDIOSPICT");
369 break;
370 }
371 }
372 } while (f);
373
374 fprintf(stdout, "P6\n%d %d 255\n", win.width, win.height);
375
376 src = buffer;
377
378 for (i = 0; i < win.width * win.height; i++) {
379 READ_VIDEO_PIXEL(src, vpic.palette, src_depth, r, g, b);
380 fputc(r>>8, stdout);
381 fputc(g>>8, stdout);
382 fputc(b>>8, stdout);
383 }
384
385 close(fd);
386 return 0;
387}
388-------------------- 8< ---------------- 8< -----------------------------
389
390
39110.0 --- Other Information
392
393Use the ../../Maintainers file, particularly the VIDEO FOR LINUX and PARALLEL
394PORT SUPPORT sections
395
396The video4linux page:
397 http://roadrunner.swansea.linux.org.uk/v4l.shtml
398
399The video4linux2 page:
400 http://millennium.diads.com/bdirks/v4l2.htm
401
402Some web pages about the quickcams:
403 http://www.dkfz-heidelberg.de/Macromol/wedemann/mini-HOWTO-cqcam.html
404
405 http://www.crynwr.com/qcpc/ QuickCam Third-Party Drivers
406 http://www.crynwr.com/qcpc/re.html Some Reverse Engineering
407 http://cse.unl.edu/~cluening/gqcam/ v4l client
408 http://phobos.illtel.denver.co.us/pub/qcread/ doesn't use v4l
409 ftp://ftp.cs.unm.edu/pub/chris/quickcam/ Has lots of drivers
410 http://www.cs.duke.edu/~reynolds/quickcam/ Has lots of information
411
412