mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-28 14:44:10 +08:00
413 lines
13 KiB
Plaintext
413 lines
13 KiB
Plaintext
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
|
|
|
|
|