------------------------------------------------------------------------------- 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 CCD 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://www.hdk-berlin.de/~rasca/w3cam/ xawtv is available at: http://www.in-berlin.de/User/kraxel/xawtv.html HOW TO USE IT: 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 modprobe usb-ohci modprobe videodev modprobe ov511 If it is not already there (it usually is), create the video device: mknod /dev/video c 81 0 Sometimes /dev/video is a symlink 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 > 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: fix_rgb_offset TYPE: integer (Boolean) DEFAULT: 0 DESC: Some people have reported that the blue component of the image is one or so lines higher than the red component. This is only apparent in images with white objects on black backgrounds at 640x480. Setting this to 1 will realign the color planes correctly. NOTE: You will likely need a fast (500 MHz) CPU. 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//button NAME: force_rgb TYPE: integer (Boolean) DEFAULT: 0 DESC: Force image to be read in RGB instead of BGR. This option allow programs that expect RGB data (e.g. gqcam) to work with this driver. If your colors look VERY wrong, you may want to change this. NAME: buf_timeout TYPE: integer DEFAULT: 5 (seconds) DESC: Number of seconds before unused frame buffers are deallocated. Previously, memory was allocated upon open() and deallocated upon close(). Deallocation now occurs only if the driver is closed and this timeout is reached. If you are capturing frames less frequently than the default timeout, increase this. This will not make any difference with programs that capture multiple frames during an open/close cycle. 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: sensor_gbr (*** TEMPORARILY DISABLED ***) TYPE: integer (Boolean) DEFAULT: 0 DESC: This makes the sensor output GBR422 instead of YUV420. This saves the driver the trouble of converting YUV to RGB, but it currently does not work very well (the colors are not quite right) NAME: dumppix TYPE: integer (0-1) 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 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 only supported with the OV511+ chipset, and even then only on some cameras (ones that actually have the LED wired to the control pin, and not just hardwired 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) 3 VIDEO_PALETTE_RGB565 (565 16 bit RGB) 4 VIDEO_PALETTE_RGB24 (24bit RGB) 7 VIDEO_PALETTE_YUV422 (YUV422 capture) 8 VIDEO_PALETTE_YUYV (YUV422 capture; same as 7) 10 VIDEO_PALETTE_YUV420 (YUV 4:2:0 Planar) 13 VIDEO_PALETTE_YUV422P (YUV 4:2:2 Planar) 15 VIDEO_PALETTE_YUV420P (YUV 4:2:0 Planar, same as 10) NAME: tuner TYPE: integer DEFAULT: -1 (autodetect) DESC: This sets the exact type of the tuner module in a device. This is set automatically based on the custom ID of the OV511 device. In cases where this fails, you can override this autodetection. Please see linux/drivers/media/video/tuner.h for a complete list. 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. WORKING FEATURES: o Color streaming/capture at most widths and heights that are multiples of 8. o RGB24, RGB565, YUV420, YUV422, YUYV, and YUV422P color o Monochrome 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 EXPERIMENTAL FEATURES: o fix_rgb_offset: Sometimes works, but other times causes errors with xawtv and corrupted frames. If you have a very fast CPU, you can try it. o Snapshot mode o 176x144, 160x120 o OV6630 sensor support o Compression support o Banding filter TO-DO: o V4L2 support (This will be done after the next kernel patch release) o Setting of hue not working with OV7620 o Setting of contrast and hue not working with OV7620AE o Driver/camera state save/restore for when USB supports suspend/resume o Unstable on SMP systems o Driver sometimes hangs upon close() with OHCI o The image should always be written properly to the mmap'ed buffer as long as the requested image size is at least the minimum size. This will likely require a rewrite of all the parsing code. o OV8600 sensor support (Not used in anything yet) o OV518/OV518+ support o cams >= 3 not working HOW TO CONTACT ME: You can email me at mmcclell@bigfoot.com . 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.