1 2 W996[87]CF JPEG USB Dual Mode Camera Chip 3 Driver for Linux 2.6 (basic version) 4 ========================================= 5 6 - Documentation - 7 8 9Index 10===== 111. Copyright 122. Disclaimer 133. License 144. Overview 155. Supported devices 166. Module dependencies 177. Module loading 188. Module parameters 199. Contact information 2010. Credits 21 22 231. Copyright 24============ 25Copyright (C) 2002-2004 by Luca Risolia <luca.risolia@studio.unibo.it> 26 27 282. Disclaimer 29============= 30Winbond is a trademark of Winbond Electronics Corporation. 31This software is not sponsored or developed by Winbond. 32 33 343. License 35========== 36This program is free software; you can redistribute it and/or modify 37it under the terms of the GNU General Public License as published by 38the Free Software Foundation; either version 2 of the License, or 39(at your option) any later version. 40 41This program is distributed in the hope that it will be useful, 42but WITHOUT ANY WARRANTY; without even the implied warranty of 43MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 44GNU General Public License for more details. 45 46You should have received a copy of the GNU General Public License 47along with this program; if not, write to the Free Software 48Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 49 50 514. Overview 52=========== 53This driver supports the video streaming capabilities of the devices mounting 54Winbond W9967CF and Winbond W9968CF JPEG USB Dual Mode Camera Chips. OV681 55based cameras should be supported as well. 56 57The driver is divided into two modules: the basic one, "w9968cf", is needed for 58the supported devices to work; the second one, "w9968cf-vpp", is an optional 59module, which provides some useful video post-processing functions like video 60decoding, up-scaling and colour conversions. 61 62Note that the official kernels do neither include nor support the second 63module for performance purposes. Therefore, it is always recommended to 64download and install the latest and complete release of the driver, 65replacing the existing one, if present. 66 67The latest and full-featured version of the W996[87]CF driver can be found at: 68http://www.linux-projects.org. Please refer to the documentation included in 69that package, if you are going to use it. 70 71Up to 32 cameras can be handled at the same time. They can be connected and 72disconnected from the host many times without turning off the computer, if 73your system supports the hotplug facility. 74 75To change the default settings for each camera, many parameters can be passed 76through command line when the module is loaded into memory. 77 78The driver relies on the Video4Linux, USB and I2C core modules. It has been 79designed to run properly on SMP systems as well. An additional module, 80"ovcamchip", is mandatory; it provides support for some OmniVision image 81sensors connected to the W996[87]CF chips; if found in the system, the module 82will be automatically loaded by default (provided that the kernel has been 83compiled with the automatic module loading option). 84 85 865. Supported devices 87==================== 88At the moment, known W996[87]CF and OV681 based devices are: 89- Aroma Digi Pen VGA Dual Mode ADG-5000 (unknown image sensor) 90- AVerMedia AVerTV USB (SAA7111A, Philips FI1216Mk2 tuner, PT2313L audio chip) 91- Creative Labs Video Blaster WebCam Go (OmniVision OV7610 sensor) 92- Creative Labs Video Blaster WebCam Go Plus (OmniVision OV7620 sensor) 93- Lebon LDC-035A (unknown image sensor) 94- Ezonics EZ-802 EZMega Cam (OmniVision OV8610C sensor) 95- OmniVision OV8610-EDE (OmniVision OV8610 sensor) 96- OPCOM Digi Pen VGA Dual Mode Pen Camera (unknown image sensor) 97- Pretec Digi Pen-II (OmniVision OV7620 sensor) 98- Pretec DigiPen-480 (OmniVision OV8610 sensor) 99 100If you know any other W996[87]CF or OV681 based cameras, please contact me. 101 102The list above does not imply that all those devices work with this driver: up 103until now only webcams that have an image sensor supported by the "ovcamchip" 104module work. Kernel messages will always tell you whether this is case. 105 106Possible external microcontrollers of those webcams are not supported: this 107means that still images cannot be downloaded from the device memory. 108 109Furthermore, it's worth to note that I was only able to run tests on my 110"Creative Labs Video Blaster WebCam Go". Donations of other models, for 111additional testing and full support, would be much appreciated. 112 113 1146. Module dependencies 115====================== 116For it to work properly, the driver needs kernel support for Video4Linux, USB 117and I2C, and the "ovcamchip" module for the image sensor. Make sure you are not 118actually using any external "ovcamchip" module, given that the W996[87]CF 119driver depends on the version of the module present in the official kernels. 120 121The following options of the kernel configuration file must be enabled and 122corresponding modules must be compiled: 123 124 # Multimedia devices 125 # 126 CONFIG_VIDEO_DEV=m 127 128 # I2C support 129 # 130 CONFIG_I2C=m 131 132The I2C core module can be compiled statically in the kernel as well. 133 134 # OmniVision Camera Chip support 135 # 136 CONFIG_VIDEO_OVCAMCHIP=m 137 138 # USB support 139 # 140 CONFIG_USB=m 141 142In addition, depending on the hardware being used, only one of the modules 143below is necessary: 144 145 # USB Host Controller Drivers 146 # 147 CONFIG_USB_EHCI_HCD=m 148 CONFIG_USB_UHCI_HCD=m 149 CONFIG_USB_OHCI_HCD=m 150 151And finally: 152 153 # USB Multimedia devices 154 # 155 CONFIG_USB_W9968CF=m 156 157 1587. Module loading 159================= 160To use the driver, it is necessary to load the "w9968cf" module into memory 161after every other module required. 162 163Loading can be done this way, from root: 164 165 [root@localhost home]# modprobe usbcore 166 [root@localhost home]# modprobe i2c-core 167 [root@localhost home]# modprobe videodev 168 [root@localhost home]# modprobe w9968cf 169 170At this point the pertinent devices should be recognized: "dmesg" can be used 171to analyze kernel messages: 172 173 [user@localhost home]$ dmesg 174 175There are a lot of parameters the module can use to change the default 176settings for each device. To list every possible parameter with a brief 177explanation about them and which syntax to use, it is recommended to run the 178"modinfo" command: 179 180 [root@locahost home]# modinfo w9968cf 181 182 1838. Module parameters 184==================== 185Module parameters are listed below: 186------------------------------------------------------------------------------- 187Name: ovmod_load 188Type: bool 189Syntax: <0|1> 190Description: Automatic 'ovcamchip' module loading: 0 disabled, 1 enabled. 191 If enabled, 'insmod' searches for the required 'ovcamchip' 192 module in the system, according to its configuration, and 193 loads that module automatically. This action is performed as 194 once soon as the 'w9968cf' module is loaded into memory. 195Default: 1 196------------------------------------------------------------------------------- 197Name: simcams 198Type: int 199Syntax: <n> 200Description: Number of cameras allowed to stream simultaneously. 201 n may vary from 0 to 32. 202Default: 32 203------------------------------------------------------------------------------- 204Name: video_nr 205Type: int array (min = 0, max = 32) 206Syntax: <-1|n[,...]> 207Description: Specify V4L minor mode number. 208 -1 = use next available 209 n = use minor number n 210 You can specify up to 32 cameras this way. 211 For example: 212 video_nr=-1,2,-1 would assign minor number 2 to the second 213 recognized camera and use auto for the first one and for every 214 other camera. 215Default: -1 216------------------------------------------------------------------------------- 217Name: packet_size 218Type: int array (min = 0, max = 32) 219Syntax: <n[,...]> 220Description: Specify the maximum data payload size in bytes for alternate 221 settings, for each device. n is scaled between 63 and 1023. 222Default: 1023 223------------------------------------------------------------------------------- 224Name: max_buffers 225Type: int array (min = 0, max = 32) 226Syntax: <n[,...]> 227Description: For advanced users. 228 Specify the maximum number of video frame buffers to allocate 229 for each device, from 2 to 32. 230Default: 2 231------------------------------------------------------------------------------- 232Name: double_buffer 233Type: bool array (min = 0, max = 32) 234Syntax: <0|1[,...]> 235Description: Hardware double buffering: 0 disabled, 1 enabled. 236 It should be enabled if you want smooth video output: if you 237 obtain out of sync. video, disable it, or try to 238 decrease the 'clockdiv' module parameter value. 239Default: 1 for every device. 240------------------------------------------------------------------------------- 241Name: clamping 242Type: bool array (min = 0, max = 32) 243Syntax: <0|1[,...]> 244Description: Video data clamping: 0 disabled, 1 enabled. 245Default: 0 for every device. 246------------------------------------------------------------------------------- 247Name: filter_type 248Type: int array (min = 0, max = 32) 249Syntax: <0|1|2[,...]> 250Description: Video filter type. 251 0 none, 1 (1-2-1) 3-tap filter, 2 (2-3-6-3-2) 5-tap filter. 252 The filter is used to reduce noise and aliasing artifacts 253 produced by the CCD or CMOS image sensor. 254Default: 0 for every device. 255------------------------------------------------------------------------------- 256Name: largeview 257Type: bool array (min = 0, max = 32) 258Syntax: <0|1[,...]> 259Description: Large view: 0 disabled, 1 enabled. 260Default: 1 for every device. 261------------------------------------------------------------------------------- 262Name: upscaling 263Type: bool array (min = 0, max = 32) 264Syntax: <0|1[,...]> 265Description: Software scaling (for non-compressed video only): 266 0 disabled, 1 enabled. 267 Disable it if you have a slow CPU or you don't have enough 268 memory. 269Default: 0 for every device. 270Note: If 'w9968cf-vpp' is not present, this parameter is set to 0. 271------------------------------------------------------------------------------- 272Name: decompression 273Type: int array (min = 0, max = 32) 274Syntax: <0|1|2[,...]> 275Description: Software video decompression: 276 0 = disables decompression 277 (doesn't allow formats needing decompression). 278 1 = forces decompression 279 (allows formats needing decompression only). 280 2 = allows any permitted formats. 281 Formats supporting (de)compressed video are YUV422P and 282 YUV420P/YUV420 in any resolutions where width and height are 283 multiples of 16. 284Default: 2 for every device. 285Note: If 'w9968cf-vpp' is not present, forcing decompression is not 286 allowed; in this case this parameter is set to 2. 287------------------------------------------------------------------------------- 288Name: force_palette 289Type: int array (min = 0, max = 32) 290Syntax: <0|9|10|13|15|8|7|1|6|3|4|5[,...]> 291Description: Force picture palette. 292 In order: 293 0 = Off - allows any of the following formats: 294 9 = UYVY 16 bpp - Original video, compression disabled 295 10 = YUV420 12 bpp - Original video, compression enabled 296 13 = YUV422P 16 bpp - Original video, compression enabled 297 15 = YUV420P 12 bpp - Original video, compression enabled 298 8 = YUVY 16 bpp - Software conversion from UYVY 299 7 = YUV422 16 bpp - Software conversion from UYVY 300 1 = GREY 8 bpp - Software conversion from UYVY 301 6 = RGB555 16 bpp - Software conversion from UYVY 302 3 = RGB565 16 bpp - Software conversion from UYVY 303 4 = RGB24 24 bpp - Software conversion from UYVY 304 5 = RGB32 32 bpp - Software conversion from UYVY 305 When not 0, this parameter will override 'decompression'. 306Default: 0 for every device. Initial palette is 9 (UYVY). 307Note: If 'w9968cf-vpp' is not present, this parameter is set to 9. 308------------------------------------------------------------------------------- 309Name: force_rgb 310Type: bool array (min = 0, max = 32) 311Syntax: <0|1[,...]> 312Description: Read RGB video data instead of BGR: 313 1 = use RGB component ordering. 314 0 = use BGR component ordering. 315 This parameter has effect when using RGBX palettes only. 316Default: 0 for every device. 317------------------------------------------------------------------------------- 318Name: autobright 319Type: bool array (min = 0, max = 32) 320Syntax: <0|1[,...]> 321Description: Image sensor automatically changes brightness: 322 0 = no, 1 = yes 323Default: 0 for every device. 324------------------------------------------------------------------------------- 325Name: autoexp 326Type: bool array (min = 0, max = 32) 327Syntax: <0|1[,...]> 328Description: Image sensor automatically changes exposure: 329 0 = no, 1 = yes 330Default: 1 for every device. 331------------------------------------------------------------------------------- 332Name: lightfreq 333Type: int array (min = 0, max = 32) 334Syntax: <50|60[,...]> 335Description: Light frequency in Hz: 336 50 for European and Asian lighting, 60 for American lighting. 337Default: 50 for every device. 338------------------------------------------------------------------------------- 339Name: bandingfilter 340Type: bool array (min = 0, max = 32) 341Syntax: <0|1[,...]> 342Description: Banding filter to reduce effects of fluorescent 343 lighting: 344 0 disabled, 1 enabled. 345 This filter tries to reduce the pattern of horizontal 346 light/dark bands caused by some (usually fluorescent) lighting. 347Default: 0 for every device. 348------------------------------------------------------------------------------- 349Name: clockdiv 350Type: int array (min = 0, max = 32) 351Syntax: <-1|n[,...]> 352Description: Force pixel clock divisor to a specific value (for experts): 353 n may vary from 0 to 127. 354 -1 for automatic value. 355 See also the 'double_buffer' module parameter. 356Default: -1 for every device. 357------------------------------------------------------------------------------- 358Name: backlight 359Type: bool array (min = 0, max = 32) 360Syntax: <0|1[,...]> 361Description: Objects are lit from behind: 362 0 = no, 1 = yes 363Default: 0 for every device. 364------------------------------------------------------------------------------- 365Name: mirror 366Type: bool array (min = 0, max = 32) 367Syntax: <0|1[,...]> 368Description: Reverse image horizontally: 369 0 = no, 1 = yes 370Default: 0 for every device. 371------------------------------------------------------------------------------- 372Name: monochrome 373Type: bool array (min = 0, max = 32) 374Syntax: <0|1[,...]> 375Description: The image sensor is monochrome: 376 0 = no, 1 = yes 377Default: 0 for every device. 378------------------------------------------------------------------------------- 379Name: brightness 380Type: long array (min = 0, max = 32) 381Syntax: <n[,...]> 382Description: Set picture brightness (0-65535). 383 This parameter has no effect if 'autobright' is enabled. 384Default: 31000 for every device. 385------------------------------------------------------------------------------- 386Name: hue 387Type: long array (min = 0, max = 32) 388Syntax: <n[,...]> 389Description: Set picture hue (0-65535). 390Default: 32768 for every device. 391------------------------------------------------------------------------------- 392Name: colour 393Type: long array (min = 0, max = 32) 394Syntax: <n[,...]> 395Description: Set picture saturation (0-65535). 396Default: 32768 for every device. 397------------------------------------------------------------------------------- 398Name: contrast 399Type: long array (min = 0, max = 32) 400Syntax: <n[,...]> 401Description: Set picture contrast (0-65535). 402Default: 50000 for every device. 403------------------------------------------------------------------------------- 404Name: whiteness 405Type: long array (min = 0, max = 32) 406Syntax: <n[,...]> 407Description: Set picture whiteness (0-65535). 408Default: 32768 for every device. 409------------------------------------------------------------------------------- 410Name: debug 411Type: int 412Syntax: <n> 413Description: Debugging information level, from 0 to 6: 414 0 = none (use carefully) 415 1 = critical errors 416 2 = significant informations 417 3 = configuration or general messages 418 4 = warnings 419 5 = called functions 420 6 = function internals 421 Level 5 and 6 are useful for testing only, when only one 422 device is used. 423Default: 2 424------------------------------------------------------------------------------- 425Name: specific_debug 426Type: bool 427Syntax: <0|1> 428Description: Enable or disable specific debugging messages: 429 0 = print messages concerning every level <= 'debug' level. 430 1 = print messages concerning the level indicated by 'debug'. 431Default: 0 432------------------------------------------------------------------------------- 433 434 4359. Contact information 436====================== 437I may be contacted by e-mail at <luca.risolia@studio.unibo.it>. 438 439I can accept GPG/PGP encrypted e-mail. My GPG key ID is 'FCE635A4'. 440My public 1024-bit key should be available at your keyserver; the fingerprint 441is: '88E8 F32F 7244 68BA 3958 5D40 99DA 5D2A FCE6 35A4'. 442 443 44410. Credits 445========== 446The development would not have proceed much further without having looked at 447the source code of other drivers and without the help of several persons; in 448particular: 449 450- the I2C interface to kernel and high-level image sensor control routines have 451 been taken from the OV511 driver by Mark McClelland; 452 453- memory management code has been copied from the bttv driver by Ralph Metzler, 454 Marcus Metzler and Gerd Knorr; 455 456- the low-level I2C read function has been written by Frederic Jouault; 457 458- the low-level I2C fast write function has been written by Piotr Czerczak. 459