289 lines
11 KiB
Plaintext
289 lines
11 KiB
Plaintext
-------------------------------------------------------------------------------
|
||
Readme for Linux device driver for the OmniVision OV511 USB to camera bridge IC
|
||
-------------------------------------------------------------------------------
|
||
|
||
Author: Mark McClelland
|
||
Homepage: http://alpha.dyndns.org/ov511
|
||
|
||
INTRODUCTION:
|
||
|
||
This is a driver for the OV511, a USB-only chip used in many "webcam" devices.
|
||
Any camera using the OV511/OV511+ and the OV6620/OV7610/20/20AE should work.
|
||
Video capture devices that use the Philips SAA7111A decoder also work. It
|
||
supports streaming and capture of color or monochrome video via the Video4Linux
|
||
API. Most V4L apps are compatible with it. Most resolutions with a width and
|
||
height that are a multiple of 8 are supported.
|
||
|
||
If you need more information, please visit the OV511 homepage at the above URL.
|
||
|
||
WHAT YOU NEED:
|
||
|
||
- If you want to help with the development, get the chip's specification docs at
|
||
http://www.ovt.com/omniusbp.html
|
||
|
||
- A Video4Linux compatible frame grabber program (I recommend vidcat and xawtv)
|
||
vidcat is part of the w3cam package: http://mpx.freeshell.net/
|
||
xawtv is available at: http://linux.bytesex.org/xawtv/
|
||
|
||
HOW TO USE IT:
|
||
|
||
Note: These are simplified instructions. For complete instructions see:
|
||
http://alpha.dyndns.org/ov511/install.html
|
||
|
||
You must have first compiled USB support, support for your specific USB host
|
||
controller (UHCI or OHCI), and Video4Linux support for your kernel (I recommend
|
||
making them modules.) Make sure "Enforce bandwidth allocation" is NOT enabled.
|
||
|
||
Next, (as root):
|
||
|
||
modprobe usbcore
|
||
modprobe usb-uhci <OR> modprobe usb-ohci
|
||
modprobe videodev
|
||
modprobe ov511
|
||
|
||
If it is not already there (it usually is), create the video device:
|
||
|
||
mknod /dev/video0 c 81 0
|
||
|
||
Optionally, symlink /dev/video to /dev/video0
|
||
|
||
You will have to set permissions on this device to allow you to read/write
|
||
from it:
|
||
|
||
chmod 666 /dev/video
|
||
chmod 666 /dev/video0 (if necessary)
|
||
|
||
Now you are ready to run a video app! Both vidcat and xawtv work well for me
|
||
at 640x480.
|
||
|
||
[Using vidcat:]
|
||
|
||
vidcat -s 640x480 -p c > test.jpg
|
||
xview test.jpg
|
||
|
||
[Using xawtv:]
|
||
|
||
From the main xawtv directory:
|
||
|
||
make clean
|
||
./configure
|
||
make
|
||
make install
|
||
|
||
Now you should be able to run xawtv. Right click for the options dialog.
|
||
|
||
MODULE PARAMETERS:
|
||
|
||
You can set these with: insmod ov511 NAME=VALUE
|
||
There is currently no way to set these on a per-camera basis.
|
||
|
||
NAME: autobright
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 1
|
||
DESC: Brightness is normally under automatic control and can't be set
|
||
manually by the video app. Set to 0 for manual control.
|
||
|
||
NAME: autogain
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 1
|
||
DESC: Auto Gain Control enable. This feature is not yet implemented.
|
||
|
||
NAME: autoexp
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 1
|
||
DESC: Auto Exposure Control enable. This feature is not yet implemented.
|
||
|
||
NAME: debug
|
||
TYPE: integer (0-6)
|
||
DEFAULT: 3
|
||
DESC: Sets the threshold for printing debug messages. The higher the value,
|
||
the more is printed. The levels are cumulative, and are as follows:
|
||
0=no debug messages
|
||
1=init/detection/unload and other significant messages
|
||
2=some warning messages
|
||
3=config/control function calls
|
||
4=most function calls and data parsing messages
|
||
5=highly repetitive mesgs
|
||
|
||
NAME: snapshot
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0
|
||
DESC: Set to 1 to enable snapshot mode. read()/VIDIOCSYNC will block until
|
||
the snapshot button is pressed. Note: enabling this mode disables
|
||
/proc/video/ov511/<minor#>/button
|
||
|
||
NAME: cams
|
||
TYPE: integer (1-4 for OV511, 1-31 for OV511+)
|
||
DEFAULT: 1
|
||
DESC: Number of cameras allowed to stream simultaneously on a single bus.
|
||
Values higher than 1 reduce the data rate of each camera, allowing two
|
||
or more to be used at once. If you have a complicated setup involving
|
||
both OV511 and OV511+ cameras, trial-and-error may be necessary for
|
||
finding the optimum setting.
|
||
|
||
NAME: compress
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0
|
||
DESC: Set this to 1 to turn on the camera's compression engine. This can
|
||
potentially increase the frame rate at the expense of quality, if you
|
||
have a fast CPU. You must load the proper compression module for your
|
||
camera before starting your application (ov511_decomp or ov518_decomp).
|
||
|
||
NAME: testpat
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0
|
||
DESC: This configures the camera's sensor to transmit a colored test-pattern
|
||
instead of an image. This does not work correctly yet.
|
||
|
||
NAME: dumppix
|
||
TYPE: integer (0-2)
|
||
DEFAULT: 0
|
||
DESC: Dumps raw pixel data and skips post-processing and format conversion.
|
||
It is for debugging purposes only. Options are:
|
||
0: Disable (default)
|
||
1: Dump raw data from camera, excluding headers and trailers
|
||
2: Dumps data exactly as received from camera
|
||
|
||
NAME: led
|
||
TYPE: integer (0-2)
|
||
DEFAULT: 1 (Always on)
|
||
DESC: Controls whether the LED (the little light) on the front of the camera
|
||
is always off (0), always on (1), or only on when driver is open (2).
|
||
This is not supported with the OV511, and might only work with certain
|
||
cameras (ones that actually have the LED wired to the control pin, and
|
||
not just hard-wired to be on all the time).
|
||
|
||
NAME: dump_bridge
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0
|
||
DESC: Dumps the bridge (OV511[+] or OV518[+]) register values to the system
|
||
log. Only useful for serious debugging/development purposes.
|
||
|
||
NAME: dump_sensor
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0
|
||
DESC: Dumps the sensor register values to the system log. Only useful for
|
||
serious debugging/development purposes.
|
||
|
||
NAME: printph
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0
|
||
DESC: Setting this to 1 will dump the first 12 bytes of each isoc frame. This
|
||
is only useful if you are trying to debug problems with the isoc data
|
||
stream (i.e.: camera initializes, but vidcat hangs until Ctrl-C). Be
|
||
warned that this dumps a large number of messages to your kernel log.
|
||
|
||
NAME: phy, phuv, pvy, pvuv, qhy, qhuv, qvy, qvuv
|
||
TYPE: integer (0-63 for phy and phuv, 0-255 for rest)
|
||
DEFAULT: OV511 default values
|
||
DESC: These are registers 70h - 77h of the OV511, which control the
|
||
prediction ranges and quantization thresholds of the compressor, for
|
||
the Y and UV channels in the horizontal and vertical directions. See
|
||
the OV511 or OV511+ data sheet for more detailed descriptions. These
|
||
normally do not need to be changed.
|
||
|
||
NAME: lightfreq
|
||
TYPE: integer (0, 50, or 60)
|
||
DEFAULT: 0 (use sensor default)
|
||
DESC: Sets the sensor to match your lighting frequency. This can reduce the
|
||
appearance of "banding", i.e. horizontal lines or waves of light and
|
||
dark that are often caused by artificial lighting. Valid values are:
|
||
0 - Use default (depends on sensor, most likely 60 Hz)
|
||
50 - For European and Asian 50 Hz power
|
||
60 - For American 60 Hz power
|
||
|
||
NAME: bandingfilter
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0 (off)
|
||
DESC: Enables the sensor´s banding filter exposure algorithm. This reduces
|
||
or stabilizes the "banding" caused by some artificial light sources
|
||
(especially fluorescent). You might have to set lightfreq correctly for
|
||
this to work right. As an added bonus, this sometimes makes it
|
||
possible to capture your monitor´s output.
|
||
|
||
NAME: fastset
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0 (off)
|
||
DESC: Allows picture settings (brightness, contrast, color, and hue) to take
|
||
effect immediately, even in the middle of a frame. This reduces the
|
||
time to change settings, but can ruin frames during the change. Only
|
||
affects OmniVision sensors.
|
||
|
||
NAME: force_palette
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0 (off)
|
||
DESC: Forces the palette (color format) to a specific value. If an
|
||
application requests a different palette, it will be rejected, thereby
|
||
forcing it to try others until it succeeds. This is useful for forcing
|
||
greyscale mode with a color camera, for example. Supported modes are:
|
||
0 (Allows all the following formats)
|
||
1 VIDEO_PALETTE_GREY (Linear greyscale)
|
||
10 VIDEO_PALETTE_YUV420 (YUV 4:2:0 Planar)
|
||
15 VIDEO_PALETTE_YUV420P (YUV 4:2:0 Planar, same as 10)
|
||
|
||
NAME: backlight
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0 (off)
|
||
DESC: Setting this flag changes the exposure algorithm for OmniVision sensors
|
||
such that objects in the camera's view (i.e. your head) can be clearly
|
||
seen when they are illuminated from behind. It reduces or eliminates
|
||
the sensor's auto-exposure function, so it should only be used when
|
||
needed. Additionally, it is only supported with the OV6620 and OV7620.
|
||
|
||
NAME: unit_video
|
||
TYPE: Up to 16 comma-separated integers
|
||
DEFAULT: 0,0,0... (automatically assign the next available minor(s))
|
||
DESC: You can specify up to 16 minor numbers to be assigned to ov511 devices.
|
||
For example, "unit_video=1,3" will make the driver use /dev/video1 and
|
||
/dev/video3 for the first two devices it detects. Additional devices
|
||
will be assigned automatically starting at the first available device
|
||
node (/dev/video0 in this case). Note that you cannot specify 0 as a
|
||
minor number. This feature requires kernel version 2.4.5 or higher.
|
||
|
||
NAME: remove_zeros
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0 (do not skip any incoming data)
|
||
DESC: Setting this to 1 will remove zero-padding from incoming data. This
|
||
will compensate for the blocks of corruption that can appear when the
|
||
camera cannot keep up with the speed of the USB bus (eg. at low frame
|
||
resolutions). This feature is always enabled when compression is on.
|
||
|
||
NAME: mirror
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0 (off)
|
||
DESC: Setting this to 1 will reverse ("mirror") the image horizontally. This
|
||
might be necessary if your camera has a custom lens assembly. This has
|
||
no effect with video capture devices.
|
||
|
||
NAME: ov518_color
|
||
TYPE: integer (Boolean)
|
||
DEFAULT: 0 (off)
|
||
DESC: Enable OV518 color support. This is off by default since it doesn't
|
||
work most of the time. If you want to try it, you must also load
|
||
ov518_decomp with the "nouv=0" parameter. If you get improper colors or
|
||
diagonal lines through the image, restart your video app and try again.
|
||
Repeat as necessary.
|
||
|
||
WORKING FEATURES:
|
||
o Color streaming/capture at most widths and heights that are multiples of 8.
|
||
o Monochrome (use force_palette=1 to enable)
|
||
o Setting/getting of saturation, contrast, brightness, and hue (only some of
|
||
them work the OV7620 and OV7620AE)
|
||
o /proc status reporting
|
||
o SAA7111A video capture support at 320x240 and 640x480
|
||
o Compression support
|
||
o SMP compatibility
|
||
|
||
HOW TO CONTACT ME:
|
||
|
||
You can email me at mark@alpha.dyndns.org . Please prefix the subject line
|
||
with "OV511: " so that I am certain to notice your message.
|
||
|
||
CREDITS:
|
||
|
||
The code is based in no small part on the CPiA driver by Johannes Erdfelt,
|
||
Randy Dunlap, and others. Big thanks to them for their pioneering work on that
|
||
and the USB stack. Thanks to Bret Wallach for getting camera reg IO, ISOC, and
|
||
image capture working. Thanks to Orion Sky Lawlor, Kevin Moore, and Claudio
|
||
Matsuoka for their work as well.
|