Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
PWC(4)		       FreeBSD Kernel Interfaces Manual			PWC(4)

     pwc -- USB	webcam driver


     The pwc driver provides support for various USB webcams.  The driver is
     based on the Linux	pwc webcam driver and uses the same API.

     The following device hints	may be added to	/boot/device.hints to further
     configure the driver:
	     When power_save is	enabled	(set to	1), the	module will try	to
	     shut down the cam on close() and re-activate on open(). This will
	     save power	and turn off the LED. Not all cameras support this
	     though (the 645 and 646 don't have	power saving at	all), and some
	     models don't work either (they will shut down, but	never wake
	     up). Consider this	experimental. By default this option is	dis-
	     When enabled (set to 1) frame statistics are written to the con-
	     sole each time the	device is closed.
	     This setting defines the on time for the LED (in milliseconds).
	     One of the	interesting things that	you can	do with	this is	to-
	     gether with the	hint is	to let the LED blink
	     while the camera is in use. This:"500""500"

	     will blink	the LED	once every second. But with:"0""0"

	     the LED never goes	on, making it suitable for silent surveil-

	     By	default	the camera's LED is on solid while in use, and turned
	     off when the camera is not	used anymore.

	     This parameter works only with the	ToUCam range of	cameras	(720,
	     730, 740, 750) and	OEMs. For other	cameras	this command is
	     silently ignored, and the LED cannot be controlled.
	     This setting defines the off time for the LED (in milliseconds)
	     Sets the initial compression preference for all cameras.  With
	     this option you can control the compression factor	that the cam-
	     era uses to squeeze the image through the USB bus.	You can	set
	     the parameter between 0 and 3:

	     0	     prefer uncompressed images; if the	requested mode is not
		     available in an uncompressed format, the driver will
		     silently switch to	low compression.

	     1	     low compression.

	     2	     medium compression.

	     3	     high compression.

	     High compression takes less bandwidth of course, but it could
	     also introduce some unwanted artefacts. The default is 2, medium

	     The compression parameter does not	apply to the 645 and 646 cam-
	     eras and OEM models derived from those (only a few). Most cams
	     honour this parameter.
	     Sets the default framerate	when you open()	the device; this is to
	     accommodate some tools that don't set the framerate.  Is an inte-
	     ger in the	range of 5-30.
	     Sets the default size  when you open() the	device;	this is	to ac-
	     commodate some tools that don't set the size.  Can	be one of 'sq-
	     cif', 'qsif', 'qcif', 'sif', 'cif'	or 'vga', for an image size of
	     resp. 128x96, 160x120, 176x144, 320x240, 352x288 and 640x480 (of
	     course, only for those cameras that support these resolutions).
	     Normally when an application requests an image size that is not
	     supported by the webcam, the driver will try to set the webcam to
	     a smaller supported image size and	pad the	resulting image	with
	     borders. If you set this parameter	to 0 this behaviour is dis-
	     abled and the driver will fail image size requests	that are not
	     supported by the webcam.
	     This parameter specifies the number of internal buffers to	use
	     for storing frames	from the cam. This will	help if	the process
	     that reads	images from the	cam is a bit slow or momentarily busy.
	     However, on slow machines it only introduces lag, so choose care-
	     fully. The	default	is 3, which is reasonable. You can set it be-
	     tween 2 and 5

     The pwc driver supports the following USB webcams:

     +o	 Philips PCA645VC
     +o	 Philips PCA646VC
     +o	 Philips PCVC675K (Vesta)
     +o	 Philips PCVC680K (Vesta Pro)
     +o	 Philips PCVC690K (Vesta Pro Scan)
     +o	 Philips PCVC730K (ToUCam Fun)
     +o	 Philips PCVC740K (ToUCam Pro)
     +o	 Philips PCVC830K (ToUCam Fun II)
     +o	 Philips PCVC840K (ToUCam Pro II)
     +o	 Philips PCVC750K (ToUCam Pro Scan)
     +o	 Philips PCVC720K/40 (ToUCam XS)
     +o	 Philips SPC900NC (ToUCam Pro III)
     +o	 Logitech QuickCam Pro 3000
     +o	 Logitech QuickCam Notebook Pro	(Old version)
     +o	 Logitech QuickCam Pro 4000
     +o	 Logitech QuickCam Zoom
     +o	 Logitech QuickCam Zoom	(new model)
     +o	 Logitech QuickCam Orbit/Sphere	(Old version)
     +o	 Logitech QuickCam (reserved id	0x046D:0x08B6)
     +o	 Logitech QuickCam (reserved id	0x046D:0x08B7)
     +o	 Logitech QuickCam (reserved id	0x046D:0x08B8)
     +o	 Creative Labs Webcam 5	(Old version)
     +o	 Creative Labs Webcam Pro Ex
     +o	 Samsung MPC-C10
     +o	 Samsung MPC-C30
     +o	 Samsung SNC-35E
     +o	 Visionite VCS-UM100
     +o	 Visionite VCS-UC300
     +o	 Askey VC010 type 1
     +o	 Askey VC010 type 2
     +o	 AME Co. Afina Eye
     +o	 Sotec Afina Eye

	     device node to access the driver

     To	watch the videostream of your webcam with mplayer:

     mplayer -demuxer rawvideo -rawvideo fps=15:w=320:h=240:i420 /dev/video0

     To	record the videostream of your webcam with mencoder:

     mencoder -demuxer rawvideo	-rawvideo fps=15:w=320:h=240:i420 /dev/video0
     -ovc lavc -lavcopts vcodec=mpeg4 -o webcam.avi

     Note: Both	examples assume	you have already set your webcam size to 'sif'
     and fps to	15. This can be	done with pwcview(1): pwcview -h -s sif	-f 15

     The driver's website:


     This is free software licensed under the GPLv2; There is NO warranty; not

     Copyright (C) 2006	 Raaf

     Based on the Linux	pwc driver:

     Copyright (C) 1999-2003 Nemosoft Unv.
     Copyright (C) 2004-2006 Luc Saillard

FreeBSD	13.0		       Februari	17, 2006		  FreeBSD 13.0


Want to link to this manual page? Use this URL:

home | help