PWCVIEW(1) BSD General Commands Manual PWCVIEW(1)NAMEpwcview — view video, create jpeg snapshots and alter settings of a web‐
cam controlled by the pwc(4) driver.
SYNOPSISpwcview [options]
DESCRIPTION
The pwcview utility is used to view the video, create jpeg snapshots, and
alter the settings of a webcam controlled by the pwc(4) driver.
COMMAND LINE OPTIONS
General options:
-? Display help message
-h Run pwcview in headless mode (without the gui)
-p Enable webcam snapshot button (only works with the Free‐
BSD pwc driver and not with all cameras)
-k Add time date string to picture.
Device options:
-d device Selects the video device to open. The default is
/dev/video0
-s size Sets the webcam's video size. The default is sif. Can be
one of 'sqcif', '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).
-f fps Sets the webcam's frame rate. The default is 5. Should
be in the range of 5-30.
JPEG output options:
-c count Number of automatic jpeg snapshots to take. Set this to
-1 for unlimited automatic jpeg snapshots. The default is
0
-i interval Automatic jpeg snapshot interval in milliseconds. The
default is 3000
-q quality Quality of jpeg output images, range 0-100. The default
is 75
-o outfile Filename of the jpeg output images. This is a string that
is passed to the strftime(3) function and thus can con‐
tain the format specifiers as documented in the strf‐
time(3) man page. The default is /tmp/%Y%m%d%H%M%S.jpg
-e command Command to execute after each jpeg snapshot. This command
will be executed with the filename of the jpeg image as
it's only command line argument. If you want to execute a
command that requires multiple arguments, you can create
a wrapper shell script. The default is not to execute any
command.
Motion detection options:
-r Enable motion detection recording. When this option is
specified pwcview will write all raw YUV420P frames that
have a number of blocks with motion in them that is
higher than threshold to stdout. For this option to work
you must redirect stdout to a file or pipe it to another
command (e.g. mencoder )
-m Show detected motion. When this option is specified the
regions in the picture in which motion is detected are
displayed in negative.
-j command Command to execute when motion is detected. The default
is not to execute any command.
-g interval Minimum time in seconds between motion commands. The
default is 60 seconds.
-u sensitivity Motion detection sensitivity. The lower you set this the
more sensitive. The default is 1000.
-t threshold Motion detection threshold. The number of blocks (a block
is 8x8 pixels) that must have motion in them before any
of the actions motion record, motion fullscreen or motion
beep is taken. The default is 1.
-l frames Recording margin. The number of extra frames that are
written to stdout after the last frame that had motion in
it. The default is 15.
Video display options:
-x Create window without frame
-y Use IYUV overlay instead of YV12 overlay
-z Create the video surface in system memory (SDL_SWSURFACE)
-a Always use video surface (SDL_ANYFORMAT)
-b bpp Bits per pixel to setup video surface with. The default
is 0, which means to use the current display bits per
pixel.
MOTION DETECTIONpwcview can also detect motion in the webcam's image and write the frames
with motion in them to stdout so you can for example encode them with
mencoder to MPEG4.
Sometimes it can be useful to exclude some areas in the picture from
motion detection. With pwcview you can use the m key to enter motion mask
editing mode. In motion mask editing mode you can add areas to exclude
from motion detection with the mouse. In motion mask editing mode masked
areas are displayed in negative.
To add an area to the motion mask: move the mouse pointer to the top left
position of the area that you want to exclude and left click then move
your mouse pointer to the bottom right position of the area that you want
to exclude and left click again. You can repeat this as many times as you
want.
To remove areas from the motion mask do the same but this time use the
right mouse button. To clear the entire mask press the middle mouse but‐
ton.
You can save the motion mask with the w key. Each time pwcview starts it
will look for the mask file in the current directory and automatically
load it.
To leave motion mask editing mode press the m key again.
KEYBOARD CONTROLS
Besides the keys used for the menu system the following keys can be used:
f Toggle fullscreen mode.
p Take a manual jpeg snapshot.
q Quit the application.
m Enter/leave motion mask editing mode.
w Saves motion mask to pwcview.msk in current directory.
space Freeze/unfreeze picture.
MENU SYSTEM
With pwcview you can alter various settings of your webcam. It provides a
menu like structure where you specify what setting you want to alter with
the up arrow and down arrow. The current menu item and thus the setting
to alter will then be displayed in the title bar.
The following settings of the webcam can be altered:
framerate Use the left arrow and right arrow to change the webcam's
frame rate.
brightness Use the left arrow and right arrow to change the webcam's
brightness.
contrast Use the left arrow and right arrow to change the webcam's
contrast.
saturation Use the left arrow and right arrow to change the webcam's
saturation.
gamma Use the left arrow and right arrow to change the webcam's
gamma.
gain control Use the enter key to switch between auto and manual gain
control. Use the left arrow and right arrow in manual
mode to change the webcam's gain control.
shutter speed Use the enter key to switch between auto and manual shut‐
ter speed. Use the left arrow and right arrow in manual
mode to change the webcam's shutter speed.
white balance Use the enter key to switch between auto, manual, indoor,
outdoor and fluorescent white balance. Use the left
arrow and right arrow in manual mode to change the web‐
cam's red gain and blue gain.
contour Use the enter key to switch between auto and manual con‐
tour. Use the left arrow and right arrow in manual mode
to change the webcam's contour.
dnr mode Use the enter key to switch between the webcam's various
modes of dynamic noise reduction.
backlight compensation
Use the enter key to switch the webcam's backlight com‐
pensation on/off.
anti flicker mode
Use the enter key to switch the webcam's anti flicker
mode on/off.
color mode Use the enter key to switch the webcam to color or black
and white mode (FreeBSD only)
compression Use the left arrow and right arrow to change the webcam's
compression level.
save user settings
Use the enter key to save the current webcam settings to
the webcam's EEPROM.
restore user settings
Use the enter key to load the current webcam settings
from the webcam's EEPROM.
restore factory settings
Use the enter key to load the current webcam settings
from the factory defaults.
led on Use the left arrow and right arrow to change the webcam's
led on time.
led off Use the left arrow and right arrow to change the webcam's
led off time.
The following settings of pwcview can be altered:
time date string
Use the enter key to toggle the addition of a time date
string to the picture. (command line equivalent -k)
scaling Use the enter key to switch between none, double and full
scaling.
motion record Use the enter key to enable/disable motion recording
(command line equivalent -r)
motion fullscreen
Use the enter key to enable/disable going to full screen
mode when motion is detected.
motion beep Use the enter key to enable/disable the speaker beep when
motion is detected.
motion show Use the enter key to toggle the display of motion in neg‐
ative (command line equivalent -m)
motion command interval
Use the left arrow and right arrow to change the motion
command interval (command line equivelant -g)
motion sensitivity
Use the left arrow and right arrow to change the motion
detection sensitivity (command line equivalent -u)
motion threshold
Use the left arrow and right arrow to change the motion
detection threshold (command line equivalent -t)
recording margin
Use the left arrow and right arrow to change the record‐
ing margin (command line equivalent -l)
VIDEODISPLAYpwcview uses the SDL library to display the video of your webcam. The
default video mode used by pwcview is in general the most efficient, but
this is very much dependent on the capabilities of your video card. If it
doesn't quite work the way you want it to, you can tune the video set‐
tings with any of the command line options listed in the "Video display
options" section at the beginning of this man page. See the SDL_SetVideo‐
Mode(3) man page for exact details.
EXAMPLES
Set the webcam to vga mode at 15 fps and execute the firefox command
whenever a jpeg snapshot is taken:
pwcview-s vga -f 15 -e firefox
Take one automatic jpeg snapshot image using the default sif resolution,
save it as foo.jpg and then exit:
pwcview-h -c 1 -o foo.jpg
Run pwcview in headless mode with the webcam set to 320x240@15fps, add a
time date string to the picture, write the frames in which motion is
detected to stdout and encode them with mencoder to motion.avi:
pwcview-hkr -s sif -f 15 | mencoder -demuxer rawvideo -rawvideo
fps=15:w=320:h=240:i420 - -ovc lavc -lavcopts vcodec=mpeg4 -o motion.avi
SEE ALSO
The Linux PWC Documentation Project:
http://www.lavrsen.dk/twiki/bin/view/PWC/WebHome
pwc(4), SDL_SetVideoMode(3), strftime(3)COPYRIGHT
This is free software licensed under the GPLv2; There is NO warranty; not
even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Copyright (C) 2006-2007 Raaf
BSD Februari 17, 2006 BSD