Based on kernel version 2.6.26. Page generated on 2008-07-16 21:13 EST.
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 9 Index 10 ===== 11 1. Copyright 12 2. Disclaimer 13 3. License 14 4. Overview 15 5. Supported devices 16 6. Module dependencies 17 7. Module loading 18 8. Module parameters 19 9. Contact information 20 10. Credits 21 22 23 1. Copyright 24 ============ 25 Copyright (C) 2002-2004 by Luca Risolia <luca.risolia[AT]studio.unibo[DOT]it> 26 27 28 2. Disclaimer 29 ============= 30 Winbond is a trademark of Winbond Electronics Corporation. 31 This software is not sponsored or developed by Winbond. 32 33 34 3. License 35 ========== 36 This program is free software; you can redistribute it and/or modify 37 it under the terms of the GNU General Public License as published by 38 the Free Software Foundation; either version 2 of the License, or 39 (at your option) any later version. 40 41 This program is distributed in the hope that it will be useful, 42 but WITHOUT ANY WARRANTY; without even the implied warranty of 43 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 44 GNU General Public License for more details. 45 46 You should have received a copy of the GNU General Public License 47 along with this program; if not, write to the Free Software 48 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 49 50 51 4. Overview 52 =========== 53 This driver supports the video streaming capabilities of the devices mounting 54 Winbond W9967CF and Winbond W9968CF JPEG USB Dual Mode Camera Chips. OV681 55 based cameras should be supported as well. 56 57 The driver is divided into two modules: the basic one, "w9968cf", is needed for 58 the supported devices to work; the second one, "w9968cf-vpp", is an optional 59 module, which provides some useful video post-processing functions like video 60 decoding, up-scaling and colour conversions. 61 62 Note that the official kernels do neither include nor support the second 63 module for performance purposes. Therefore, it is always recommended to 64 download and install the latest and complete release of the driver, 65 replacing the existing one, if present. 66 67 The latest and full-featured version of the W996[87]CF driver can be found at: 68 http://www.linux-projects.org. Please refer to the documentation included in 69 that package, if you are going to use it. 70 71 Up to 32 cameras can be handled at the same time. They can be connected and 72 disconnected from the host many times without turning off the computer, if 73 your system supports the hotplug facility. 74 75 To change the default settings for each camera, many parameters can be passed 76 through command line when the module is loaded into memory. 77 78 The driver relies on the Video4Linux, USB and I2C core modules. It has been 79 designed to run properly on SMP systems as well. An additional module, 80 "ovcamchip", is mandatory; it provides support for some OmniVision image 81 sensors connected to the W996[87]CF chips; if found in the system, the module 82 will be automatically loaded by default (provided that the kernel has been 83 compiled with the automatic module loading option). 84 85 86 5. Supported devices 87 ==================== 88 At 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) 99 100 If you know any other W996[87]CF or OV681 based cameras, please contact me. 101 102 The list above does not imply that all those devices work with this driver: up 103 until now only webcams that have an image sensor supported by the "ovcamchip" 104 module work. Kernel messages will always tell you whether this is case. 105 106 Possible external microcontrollers of those webcams are not supported: this 107 means that still images cannot be downloaded from the device memory. 108 109 Furthermore, 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 111 additional testing and full support, would be much appreciated. 112 113 114 6. Module dependencies 115 ====================== 116 For it to work properly, the driver needs kernel support for Video4Linux, USB 117 and I2C, and the "ovcamchip" module for the image sensor. Make sure you are not 118 actually using any external "ovcamchip" module, given that the W996[87]CF 119 driver depends on the version of the module present in the official kernels. 120 121 The following options of the kernel configuration file must be enabled and 122 corresponding modules must be compiled: 123 124 # Multimedia devices 125 # 126 CONFIG_VIDEO_DEV=m 127 128 # I2C support 129 # 130 CONFIG_I2C=m 131 132 The 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 141 142 In addition, depending on the hardware being used, only one of the modules 143 below 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 150 151 And finally: 152 153 # USB Multimedia devices 154 # 155 CONFIG_USB_W9968CF=m 156 157 158 7. Module loading 159 ================= 160 To use the driver, it is necessary to load the "w9968cf" module into memory 161 after every other module required. 162 163 Loading 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 169 170 At this point the pertinent devices should be recognized: "dmesg" can be used 171 to analyze kernel messages: 172 173 [user@localhost home]$ dmesg 174 175 There are a lot of parameters the module can use to change the default 176 settings for each device. To list every possible parameter with a brief 177 explanation about them and which syntax to use, it is recommended to run the 178 "modinfo" command: 179 180 [root@locahost home]# modinfo w9968cf 181 182 183 8. Module parameters 184 ==================== 185 Module parameters are listed below: 186 ------------------------------------------------------------------------------- 187 Name: ovmod_load 188 Type: bool 189 Syntax: <0|1> 190 Description: 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. 195 Default: 1 196 Note: The kernel must be compiled with the CONFIG_KMOD option 197 enabled for the 'ovcamchip' module to be loaded and for 198 this parameter to be present. 199 ------------------------------------------------------------------------------- 200 Name: simcams 201 Type: int 202 Syntax: <n> 203 Description: Number of cameras allowed to stream simultaneously. 204 n may vary from 0 to 32. 205 Default: 32 206 ------------------------------------------------------------------------------- 207 Name: video_nr 208 Type: int array (min = 0, max = 32) 209 Syntax: <-1|n[,...]> 210 Description: Specify V4L minor mode number. 211 -1 = use next available 212 n = use minor number n 213 You can specify up to 32 cameras this way. 214 For example: 215 video_nr=-1,2,-1 would assign minor number 2 to the second 216 recognized camera and use auto for the first one and for every 217 other camera. 218 Default: -1 219 ------------------------------------------------------------------------------- 220 Name: packet_size 221 Type: int array (min = 0, max = 32) 222 Syntax: <n[,...]> 223 Description: Specify the maximum data payload size in bytes for alternate 224 settings, for each device. n is scaled between 63 and 1023. 225 Default: 1023 226 ------------------------------------------------------------------------------- 227 Name: max_buffers 228 Type: int array (min = 0, max = 32) 229 Syntax: <n[,...]> 230 Description: For advanced users. 231 Specify the maximum number of video frame buffers to allocate 232 for each device, from 2 to 32. 233 Default: 2 234 ------------------------------------------------------------------------------- 235 Name: double_buffer 236 Type: bool array (min = 0, max = 32) 237 Syntax: <0|1[,...]> 238 Description: Hardware double buffering: 0 disabled, 1 enabled. 239 It should be enabled if you want smooth video output: if you 240 obtain out of sync. video, disable it, or try to 241 decrease the 'clockdiv' module parameter value. 242 Default: 1 for every device. 243 ------------------------------------------------------------------------------- 244 Name: clamping 245 Type: bool array (min = 0, max = 32) 246 Syntax: <0|1[,...]> 247 Description: Video data clamping: 0 disabled, 1 enabled. 248 Default: 0 for every device. 249 ------------------------------------------------------------------------------- 250 Name: filter_type 251 Type: int array (min = 0, max = 32) 252 Syntax: <0|1|2[,...]> 253 Description: Video filter type. 254 0 none, 1 (1-2-1) 3-tap filter, 2 (2-3-6-3-2) 5-tap filter. 255 The filter is used to reduce noise and aliasing artifacts 256 produced by the CCD or CMOS image sensor. 257 Default: 0 for every device. 258 ------------------------------------------------------------------------------- 259 Name: largeview 260 Type: bool array (min = 0, max = 32) 261 Syntax: <0|1[,...]> 262 Description: Large view: 0 disabled, 1 enabled. 263 Default: 1 for every device. 264 ------------------------------------------------------------------------------- 265 Name: upscaling 266 Type: bool array (min = 0, max = 32) 267 Syntax: <0|1[,...]> 268 Description: Software scaling (for non-compressed video only): 269 0 disabled, 1 enabled. 270 Disable it if you have a slow CPU or you don't have enough 271 memory. 272 Default: 0 for every device. 273 Note: If 'w9968cf-vpp' is not present, this parameter is set to 0. 274 ------------------------------------------------------------------------------- 275 Name: decompression 276 Type: int array (min = 0, max = 32) 277 Syntax: <0|1|2[,...]> 278 Description: Software video decompression: 279 0 = disables decompression 280 (doesn't allow formats needing decompression). 281 1 = forces decompression 282 (allows formats needing decompression only). 283 2 = allows any permitted formats. 284 Formats supporting (de)compressed video are YUV422P and 285 YUV420P/YUV420 in any resolutions where width and height are 286 multiples of 16. 287 Default: 2 for every device. 288 Note: If 'w9968cf-vpp' is not present, forcing decompression is not 289 allowed; in this case this parameter is set to 2. 290 ------------------------------------------------------------------------------- 291 Name: force_palette 292 Type: int array (min = 0, max = 32) 293 Syntax: <0|9|10|13|15|8|7|1|6|3|4|5[,...]> 294 Description: Force picture palette. 295 In order: 296 0 = Off - allows any of the following formats: 297 9 = UYVY 16 bpp - Original video, compression disabled 298 10 = YUV420 12 bpp - Original video, compression enabled 299 13 = YUV422P 16 bpp - Original video, compression enabled 300 15 = YUV420P 12 bpp - Original video, compression enabled 301 8 = YUVY 16 bpp - Software conversion from UYVY 302 7 = YUV422 16 bpp - Software conversion from UYVY 303 1 = GREY 8 bpp - Software conversion from UYVY 304 6 = RGB555 16 bpp - Software conversion from UYVY 305 3 = RGB565 16 bpp - Software conversion from UYVY 306 4 = RGB24 24 bpp - Software conversion from UYVY 307 5 = RGB32 32 bpp - Software conversion from UYVY 308 When not 0, this parameter will override 'decompression'. 309 Default: 0 for every device. Initial palette is 9 (UYVY). 310 Note: If 'w9968cf-vpp' is not present, this parameter is set to 9. 311 ------------------------------------------------------------------------------- 312 Name: force_rgb 313 Type: bool array (min = 0, max = 32) 314 Syntax: <0|1[,...]> 315 Description: Read RGB video data instead of BGR: 316 1 = use RGB component ordering. 317 0 = use BGR component ordering. 318 This parameter has effect when using RGBX palettes only. 319 Default: 0 for every device. 320 ------------------------------------------------------------------------------- 321 Name: autobright 322 Type: bool array (min = 0, max = 32) 323 Syntax: <0|1[,...]> 324 Description: Image sensor automatically changes brightness: 325 0 = no, 1 = yes 326 Default: 0 for every device. 327 ------------------------------------------------------------------------------- 328 Name: autoexp 329 Type: bool array (min = 0, max = 32) 330 Syntax: <0|1[,...]> 331 Description: Image sensor automatically changes exposure: 332 0 = no, 1 = yes 333 Default: 1 for every device. 334 ------------------------------------------------------------------------------- 335 Name: lightfreq 336 Type: int array (min = 0, max = 32) 337 Syntax: <50|60[,...]> 338 Description: Light frequency in Hz: 339 50 for European and Asian lighting, 60 for American lighting. 340 Default: 50 for every device. 341 ------------------------------------------------------------------------------- 342 Name: bandingfilter 343 Type: bool array (min = 0, max = 32) 344 Syntax: <0|1[,...]> 345 Description: Banding filter to reduce effects of fluorescent 346 lighting: 347 0 disabled, 1 enabled. 348 This filter tries to reduce the pattern of horizontal 349 light/dark bands caused by some (usually fluorescent) lighting. 350 Default: 0 for every device. 351 ------------------------------------------------------------------------------- 352 Name: clockdiv 353 Type: int array (min = 0, max = 32) 354 Syntax: <-1|n[,...]> 355 Description: Force pixel clock divisor to a specific value (for experts): 356 n may vary from 0 to 127. 357 -1 for automatic value. 358 See also the 'double_buffer' module parameter. 359 Default: -1 for every device. 360 ------------------------------------------------------------------------------- 361 Name: backlight 362 Type: bool array (min = 0, max = 32) 363 Syntax: <0|1[,...]> 364 Description: Objects are lit from behind: 365 0 = no, 1 = yes 366 Default: 0 for every device. 367 ------------------------------------------------------------------------------- 368 Name: mirror 369 Type: bool array (min = 0, max = 32) 370 Syntax: <0|1[,...]> 371 Description: Reverse image horizontally: 372 0 = no, 1 = yes 373 Default: 0 for every device. 374 ------------------------------------------------------------------------------- 375 Name: monochrome 376 Type: bool array (min = 0, max = 32) 377 Syntax: <0|1[,...]> 378 Description: The image sensor is monochrome: 379 0 = no, 1 = yes 380 Default: 0 for every device. 381 ------------------------------------------------------------------------------- 382 Name: brightness 383 Type: long array (min = 0, max = 32) 384 Syntax: <n[,...]> 385 Description: Set picture brightness (0-65535). 386 This parameter has no effect if 'autobright' is enabled. 387 Default: 31000 for every device. 388 ------------------------------------------------------------------------------- 389 Name: hue 390 Type: long array (min = 0, max = 32) 391 Syntax: <n[,...]> 392 Description: Set picture hue (0-65535). 393 Default: 32768 for every device. 394 ------------------------------------------------------------------------------- 395 Name: colour 396 Type: long array (min = 0, max = 32) 397 Syntax: <n[,...]> 398 Description: Set picture saturation (0-65535). 399 Default: 32768 for every device. 400 ------------------------------------------------------------------------------- 401 Name: contrast 402 Type: long array (min = 0, max = 32) 403 Syntax: <n[,...]> 404 Description: Set picture contrast (0-65535). 405 Default: 50000 for every device. 406 ------------------------------------------------------------------------------- 407 Name: whiteness 408 Type: long array (min = 0, max = 32) 409 Syntax: <n[,...]> 410 Description: Set picture whiteness (0-65535). 411 Default: 32768 for every device. 412 ------------------------------------------------------------------------------- 413 Name: debug 414 Type: int 415 Syntax: <n> 416 Description: Debugging information level, from 0 to 6: 417 0 = none (use carefully) 418 1 = critical errors 419 2 = significant informations 420 3 = configuration or general messages 421 4 = warnings 422 5 = called functions 423 6 = function internals 424 Level 5 and 6 are useful for testing only, when only one 425 device is used. 426 Default: 2 427 ------------------------------------------------------------------------------- 428 Name: specific_debug 429 Type: bool 430 Syntax: <0|1> 431 Description: Enable or disable specific debugging messages: 432 0 = print messages concerning every level <= 'debug' level. 433 1 = print messages concerning the level indicated by 'debug'. 434 Default: 0 435 ------------------------------------------------------------------------------- 436 437 438 9. Contact information 439 ====================== 440 I may be contacted by e-mail at <luca.risolia[AT]studio.unibo.it>[DOT] 441 442 I can accept GPG/PGP encrypted e-mail. My GPG key ID is 'FCE635A4'. 443 My public 1024-bit key should be available at your keyserver; the fingerprint 444 is: '88E8 F32F 7244 68BA 3958 5D40 99DA 5D2A FCE6 35A4'. 445 446 447 10. Credits 448 ========== 449 The development would not have proceed much further without having looked at 450 the source code of other drivers and without the help of several persons; in 451 particular: 452 453 - the I2C interface to kernel and high-level image sensor control routines have 454 been taken from the OV511 driver by Mark McClelland; 455 456 - memory management code has been copied from the bttv driver by Ralph Metzler, 457 Marcus Metzler and Gerd Knorr; 458 459 - the low-level I2C read function has been written by Frederic Jouault; 460 461 - the low-level I2C fast write function has been written by Piotr Czerczak.