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Based on kernel version 3.8. Page generated on 2013-02-20 22:08 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@studio.unibo.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	-------------------------------------------------------------------------------
197	Name:           simcams
198	Type:           int
199	Syntax:         <n>
200	Description:    Number of cameras allowed to stream simultaneously.
201			n may vary from 0 to 32.
202	Default:        32
203	-------------------------------------------------------------------------------
204	Name:           video_nr
205	Type:           int array (min = 0, max = 32)
206	Syntax:         <-1|n[,...]>
207	Description:    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.
215	Default:        -1
216	-------------------------------------------------------------------------------
217	Name:           packet_size
218	Type:           int array (min = 0, max = 32)
219	Syntax:         <n[,...]>
220	Description:    Specify the maximum data payload size in bytes for alternate
221			settings, for each device. n is scaled between 63 and 1023.
222	Default:        1023
223	-------------------------------------------------------------------------------
224	Name:           max_buffers
225	Type:           int array (min = 0, max = 32)
226	Syntax:         <n[,...]>
227	Description:    For advanced users.
228			Specify the maximum number of video frame buffers to allocate
229			for each device, from 2 to 32.
230	Default:        2
231	-------------------------------------------------------------------------------
232	Name:           double_buffer
233	Type:           bool array (min = 0, max = 32)
234	Syntax:         <0|1[,...]>
235	Description:    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.
239	Default:        1 for every device.
240	-------------------------------------------------------------------------------
241	Name:           clamping
242	Type:           bool array (min = 0, max = 32)
243	Syntax:         <0|1[,...]>
244	Description:    Video data clamping: 0 disabled, 1 enabled.
245	Default:        0 for every device.
246	-------------------------------------------------------------------------------
247	Name:           filter_type
248	Type:           int array (min = 0, max = 32)
249	Syntax:         <0|1|2[,...]>
250	Description:    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.
254	Default:        0 for every device.
255	-------------------------------------------------------------------------------
256	Name:           largeview
257	Type:           bool array (min = 0, max = 32)
258	Syntax:         <0|1[,...]>
259	Description:    Large view: 0 disabled, 1 enabled.
260	Default:        1 for every device.
261	-------------------------------------------------------------------------------
262	Name:           upscaling
263	Type:           bool array (min = 0, max = 32)
264	Syntax:         <0|1[,...]>
265	Description:    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.
269	Default:        0 for every device.
270	Note:           If 'w9968cf-vpp' is not present, this parameter is set to 0.
271	-------------------------------------------------------------------------------
272	Name:           decompression
273	Type:           int array (min = 0, max = 32)
274	Syntax:         <0|1|2[,...]>
275	Description:    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.
284	Default:        2 for every device.
285	Note:           If 'w9968cf-vpp' is not present, forcing decompression is not
286			allowed; in this case this parameter is set to 2.
287	-------------------------------------------------------------------------------
288	Name:           force_palette
289	Type:           int array (min = 0, max = 32)
290	Syntax:         <0|9|10|13|15|8|7|1|6|3|4|5[,...]>
291	Description:    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'.
306	Default:        0 for every device. Initial palette is 9 (UYVY).
307	Note:           If 'w9968cf-vpp' is not present, this parameter is set to 9.
308	-------------------------------------------------------------------------------
309	Name:           force_rgb
310	Type:           bool array (min = 0, max = 32)
311	Syntax:         <0|1[,...]>
312	Description:    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.
316	Default:        0 for every device.
317	-------------------------------------------------------------------------------
318	Name:           autobright
319	Type:           bool array (min = 0, max = 32)
320	Syntax:         <0|1[,...]>
321	Description:    Image sensor automatically changes brightness:
322			0 = no, 1 = yes
323	Default:        0 for every device.
324	-------------------------------------------------------------------------------
325	Name:           autoexp
326	Type:           bool array (min = 0, max = 32)
327	Syntax:         <0|1[,...]>
328	Description:    Image sensor automatically changes exposure:
329			0 = no, 1 = yes
330	Default:        1 for every device.
331	-------------------------------------------------------------------------------
332	Name:           lightfreq
333	Type:           int array (min = 0, max = 32)
334	Syntax:         <50|60[,...]>
335	Description:    Light frequency in Hz:
336			50 for European and Asian lighting, 60 for American lighting.
337	Default:        50 for every device.
338	-------------------------------------------------------------------------------
339	Name:           bandingfilter
340	Type:           bool array (min = 0, max = 32)
341	Syntax:         <0|1[,...]>
342	Description:    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.
347	Default:        0 for every device.
348	-------------------------------------------------------------------------------
349	Name:           clockdiv
350	Type:           int array (min = 0, max = 32)
351	Syntax:         <-1|n[,...]>
352	Description:    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.
356	Default:        -1 for every device.
357	-------------------------------------------------------------------------------
358	Name:           backlight
359	Type:           bool array (min = 0, max = 32)
360	Syntax:         <0|1[,...]>
361	Description:    Objects are lit from behind:
362			0 = no, 1 = yes
363	Default:        0 for every device.
364	-------------------------------------------------------------------------------
365	Name:           mirror
366	Type:           bool array (min = 0, max = 32)
367	Syntax:         <0|1[,...]>
368	Description:    Reverse image horizontally:
369			0 = no, 1 = yes
370	Default:        0 for every device.
371	-------------------------------------------------------------------------------
372	Name:           monochrome
373	Type:           bool array (min = 0, max = 32)
374	Syntax:         <0|1[,...]>
375	Description:    The image sensor is monochrome:
376			0 = no, 1 = yes
377	Default:        0 for every device.
378	-------------------------------------------------------------------------------
379	Name:           brightness
380	Type:           long array (min = 0, max = 32)
381	Syntax:         <n[,...]>
382	Description:    Set picture brightness (0-65535).
383			This parameter has no effect if 'autobright' is enabled.
384	Default:        31000 for every device.
385	-------------------------------------------------------------------------------
386	Name:           hue
387	Type:           long array (min = 0, max = 32)
388	Syntax:         <n[,...]>
389	Description:    Set picture hue (0-65535).
390	Default:        32768 for every device.
391	-------------------------------------------------------------------------------
392	Name:           colour
393	Type:           long array (min = 0, max = 32)
394	Syntax:         <n[,...]>
395	Description:    Set picture saturation (0-65535).
396	Default:        32768 for every device.
397	-------------------------------------------------------------------------------
398	Name:           contrast
399	Type:           long array (min = 0, max = 32)
400	Syntax:         <n[,...]>
401	Description:    Set picture contrast (0-65535).
402	Default:        50000 for every device.
403	-------------------------------------------------------------------------------
404	Name:           whiteness
405	Type:           long array (min = 0, max = 32)
406	Syntax:         <n[,...]>
407	Description:    Set picture whiteness (0-65535).
408	Default:        32768 for every device.
409	-------------------------------------------------------------------------------
410	Name:           debug
411	Type:           int
412	Syntax:         <n>
413	Description:    Debugging information level, from 0 to 6:
414			0 = none (use carefully)
415			1 = critical errors
416			2 = significant information
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.
423	Default:        2
424	-------------------------------------------------------------------------------
425	Name:           specific_debug
426	Type:           bool
427	Syntax:         <0|1>
428	Description:    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'.
431	Default:        0
432	-------------------------------------------------------------------------------
433	
434	
435	9. Contact information
436	======================
437	I may be contacted by e-mail at <luca.risolia@studio.unibo.it>.
438	
439	I can accept GPG/PGP encrypted e-mail. My GPG key ID is 'FCE635A4'.
440	My public 1024-bit key should be available at your keyserver; the fingerprint
441	is: '88E8 F32F 7244 68BA 3958  5D40 99DA 5D2A FCE6 35A4'.
442	
443	
444	10. Credits
445	==========
446	The development would not have proceed much further without having looked at
447	the source code of other drivers and without the help of several persons; in
448	particular:
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.
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