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diff --git a/Documentation/video4linux/ov511.txt b/Documentation/video4linux/ov511.txt new file mode 100644 index 0000000..142741e --- /dev/null +++ b/Documentation/video4linux/ov511.txt @@ -0,0 +1,288 @@ +------------------------------------------------------------------------------- +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 sensorīs 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 monitorīs 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. |
