| 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/char/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, |
| |
| This program 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) Using this like: 'v4lgrab | convert - c-qcam.jpg' |
| produced this picture of me at |
| http://mug.sys.virginia.edu/~drf5n/extras/c-qcam.jpg |
| |
| -------------------- 8< ---------------- 8< ----------------------------- |
| |
| /* Simple Video4Linux image grabber. */ |
| /* |
| * Video4Linux Driver Test/Example Framegrabbing Program |
| * |
| * Compile with: |
| * gcc -s -Wall -Wstrict-prototypes v4lgrab.c -o v4lgrab |
| * Use as: |
| * v4lgrab >image.ppm |
| * |
| * Copyright (C) 1998-05-03, Phil Blundell <philb@gnu.org> |
| * Copied from http://www.tazenda.demon.co.uk/phil/vgrabber.c |
| * with minor modifications (Dave Forrest, drf5n@virginia.edu). |
| * |
| */ |
| |
| #include <unistd.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| #include <stdio.h> |
| #include <sys/ioctl.h> |
| #include <stdlib.h> |
| |
| #include <linux/types.h> |
| #include <linux/videodev.h> |
| |
| #define FILE "/dev/video0" |
| |
| /* Stole this from tvset.c */ |
| |
| #define READ_VIDEO_PIXEL(buf, format, depth, r, g, b) \ |
| { \ |
| switch (format) \ |
| { \ |
| case VIDEO_PALETTE_GREY: \ |
| switch (depth) \ |
| { \ |
| case 4: \ |
| case 6: \ |
| case 8: \ |
| (r) = (g) = (b) = (*buf++ << 8);\ |
| break; \ |
| \ |
| case 16: \ |
| (r) = (g) = (b) = \ |
| *((unsigned short *) buf); \ |
| buf += 2; \ |
| break; \ |
| } \ |
| break; \ |
| \ |
| \ |
| case VIDEO_PALETTE_RGB565: \ |
| { \ |
| unsigned short tmp = *(unsigned short *)buf; \ |
| (r) = tmp&0xF800; \ |
| (g) = (tmp<<5)&0xFC00; \ |
| (b) = (tmp<<11)&0xF800; \ |
| buf += 2; \ |
| } \ |
| break; \ |
| \ |
| case VIDEO_PALETTE_RGB555: \ |
| (r) = (buf[0]&0xF8)<<8; \ |
| (g) = ((buf[0] << 5 | buf[1] >> 3)&0xF8)<<8; \ |
| (b) = ((buf[1] << 2 ) & 0xF8)<<8; \ |
| buf += 2; \ |
| break; \ |
| \ |
| case VIDEO_PALETTE_RGB24: \ |
| (r) = buf[0] << 8; (g) = buf[1] << 8; \ |
| (b) = buf[2] << 8; \ |
| buf += 3; \ |
| break; \ |
| \ |
| default: \ |
| fprintf(stderr, \ |
| "Format %d not yet supported\n", \ |
| format); \ |
| } \ |
| } |
| |
| int get_brightness_adj(unsigned char *image, long size, int *brightness) { |
| long i, tot = 0; |
| for (i=0;i<size*3;i++) |
| tot += image[i]; |
| *brightness = (128 - tot/(size*3))/3; |
| return !((tot/(size*3)) >= 126 && (tot/(size*3)) <= 130); |
| } |
| |
| int main(int argc, char ** argv) |
| { |
| int fd = open(FILE, O_RDONLY), f; |
| struct video_capability cap; |
| struct video_window win; |
| struct video_picture vpic; |
| |
| unsigned char *buffer, *src; |
| int bpp = 24, r, g, b; |
| unsigned int i, src_depth; |
| |
| if (fd < 0) { |
| perror(FILE); |
| exit(1); |
| } |
| |
| if (ioctl(fd, VIDIOCGCAP, &cap) < 0) { |
| perror("VIDIOGCAP"); |
| fprintf(stderr, "(" FILE " not a video4linux device?)\n"); |
| close(fd); |
| exit(1); |
| } |
| |
| if (ioctl(fd, VIDIOCGWIN, &win) < 0) { |
| perror("VIDIOCGWIN"); |
| close(fd); |
| exit(1); |
| } |
| |
| if (ioctl(fd, VIDIOCGPICT, &vpic) < 0) { |
| perror("VIDIOCGPICT"); |
| close(fd); |
| exit(1); |
| } |
| |
| if (cap.type & VID_TYPE_MONOCHROME) { |
| vpic.depth=8; |
| vpic.palette=VIDEO_PALETTE_GREY; /* 8bit grey */ |
| if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) { |
| vpic.depth=6; |
| if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) { |
| vpic.depth=4; |
| if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) { |
| fprintf(stderr, "Unable to find a supported capture format.\n"); |
| close(fd); |
| exit(1); |
| } |
| } |
| } |
| } else { |
| vpic.depth=24; |
| vpic.palette=VIDEO_PALETTE_RGB24; |
| |
| if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) { |
| vpic.palette=VIDEO_PALETTE_RGB565; |
| vpic.depth=16; |
| |
| if(ioctl(fd, VIDIOCSPICT, &vpic)==-1) { |
| vpic.palette=VIDEO_PALETTE_RGB555; |
| vpic.depth=15; |
| |
| if(ioctl(fd, VIDIOCSPICT, &vpic)==-1) { |
| fprintf(stderr, "Unable to find a supported capture format.\n"); |
| return -1; |
| } |
| } |
| } |
| } |
| |
| buffer = malloc(win.width * win.height * bpp); |
| if (!buffer) { |
| fprintf(stderr, "Out of memory.\n"); |
| exit(1); |
| } |
| |
| do { |
| int newbright; |
| read(fd, buffer, win.width * win.height * bpp); |
| f = get_brightness_adj(buffer, win.width * win.height, &newbright); |
| if (f) { |
| vpic.brightness += (newbright << 8); |
| if(ioctl(fd, VIDIOCSPICT, &vpic)==-1) { |
| perror("VIDIOSPICT"); |
| break; |
| } |
| } |
| } while (f); |
| |
| fprintf(stdout, "P6\n%d %d 255\n", win.width, win.height); |
| |
| src = buffer; |
| |
| for (i = 0; i < win.width * win.height; i++) { |
| READ_VIDEO_PIXEL(src, vpic.palette, src_depth, r, g, b); |
| fputc(r>>8, stdout); |
| fputc(g>>8, stdout); |
| fputc(b>>8, stdout); |
| } |
| |
| close(fd); |
| return 0; |
| } |
| -------------------- 8< ---------------- 8< ----------------------------- |
| |
| |
| 10.0 --- Other Information |
| |
| Use the ../../Maintainers file, particularly the VIDEO FOR LINUX and PARALLEL |
| PORT SUPPORT sections |
| |
| The video4linux page: |
| http://roadrunner.swansea.linux.org.uk/v4l.shtml |
| |
| The video4linux2 page: |
| http://millennium.diads.com/bdirks/v4l2.htm |
| |
| Some web pages about the quickcams: |
| http://www.dkfz-heidelberg.de/Macromol/wedemann/mini-HOWTO-cqcam.html |
| |
| http://www.crynwr.com/qcpc/ QuickCam Third-Party Drivers |
| http://www.crynwr.com/qcpc/re.html Some Reverse Engineering |
| http://cse.unl.edu/~cluening/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 |
| |
| |
