|video(1)||record or display images from video 4|
|video(4)||device-independent video driver layer|
|VIDEO(1)||General Commands Manual||VIDEO(1)|
videois a utility for reading, writing and displaying streams of raw video frames. By default frames are read from file and displayed via Xv(3). The default file is /dev/video. If the
-ooption is used frames are read from file and written to output. If the
-ioption is used frames are read from input and displayed via Xv(3). If the
-Ooption is used frames are read from file, written to output and displayed via Xv(3). The acutance, brightness, contrast, gain, gamma, hue and saturation controls of file can also be adjusted if file supports these controls.
The options are as follows:
yuy2’ and ‘
yv12’. The default is ‘
yuy2’ unless file is being used and only supports ‘
uyvy’, in which case ‘
uyvy’ will be used by default.
-’, frames will be read from standard input.
-’, frames will be written to standard output. In contrast to
-o, if this option is used,
videowill also display the frames via Xv(3).
-’, frames will be written to standard output.
-roption is not specified, frames will be read as quickly as possible. If reading from a video(4) device, the device's frame rate will be set to the frame rate the device supports that is closest to rate. Frames will be read as quickly as they are available from the device, but will be displayed and/or written to output at the rate specified, unless the
-Roption is used.
x’, size is interpreted as only the width. If ‘
x’ is the first character of size, the characters following ‘
x’ are interpreted as the height. If only one of width or height is specified, the other will be calculated using a 4:3 width:height ratio. For example, if given ‘
videowill use a size of ‘
640x480’. When reading from a video(4) device and displaying the frames on an Xv(3) display, this option also accepts two special strings, ‘
half’ and ‘
full.’ If either ‘
half’ or ‘
full’ are specified,
videowill read frames that are no larger than 2/3 the display width and 2/3 the display height. If ‘
full’ is specified,
videowill stretch the frame to the full size of the display using Xv(3) scaling. If
videois reading frames from a video(4) device and the frame size does not match a frame size the device supports,
videowill use the largest frame size supported by the device that is smaller than the specified size.
video will quit reading frames and exit
nicely if it receives any of the following signals: SIGHUP, SIGINT, SIGKILL,
video responds to certain key presses
while it is displaying frames. The keypresses are as follows:
-Ooption is used.
-Ooption is used.
The following command will read YUY2 encoded, 640 pixel wide and 480 pixel high video frames from /dev/video and write them to video.raw at a rate of 15 frames per second:
$ video -r 15 -o video.raw
The following command will read YUY2 encoded, 640 pixel wide and 480 pixel high video frames from /dev/video, write them to video.raw and display them using the default Xv(3) adaptor at a rate of 15 frames per second:
$ video -r 15 -O video.raw
The following command will read YUY2 encoded, 640 pixel wide and 480 pixel high video frames from video.raw and display them on the default Xv(3) adaptor at a rate of 15 frames per second:
$ video -r 15 -i video.raw
Note that with the first three commands, if /dev/video does not support 640x480 pixels sized frames, the largest frame size smaller than 640x480 will be used, and if /dev/video does not support yuy2 encoding, uyvy will be used.
|February 25, 2019||OpenBSD-current|