diff options
Diffstat (limited to 'Documentation/video4linux')
| -rw-r--r-- | Documentation/video4linux/CQcam.txt | 414 | ||||
| -rw-r--r-- | Documentation/video4linux/bttv/README | 2 |
2 files changed, 415 insertions, 1 deletions
diff --git a/Documentation/video4linux/CQcam.txt b/Documentation/video4linux/CQcam.txt new file mode 100644 index 000000000..6d54c07c0 --- /dev/null +++ b/Documentation/video4linux/CQcam.txt @@ -0,0 +1,414 @@ +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 dep; \ + 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/modules.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. Do read ../modules.txt, and understand that entries +in /etc/modules.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/kerneld/modprobe to do certain things. If you are +using kmod or kerneld, 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 sytem,(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 + + diff --git a/Documentation/video4linux/bttv/README b/Documentation/video4linux/bttv/README index 9d0709a57..4d8298772 100644 --- a/Documentation/video4linux/bttv/README +++ b/Documentation/video4linux/bttv/README @@ -17,7 +17,7 @@ CONFIG_I2C=m CONFIG_I2C_ALGOBIT=m The latest bttv version is available here: - http://www.in-berlin.de/User/kraxel/v4l/ + http://me.in-berlin.de/~kraxel/bttv.html You'll find Ralphs original (mostly outdated) documentation in the ralphs-doc subdirectory. |