| ------------------------------------------------------------------------------- |
| 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. |
