v4l2caps

Video for Linux capture plugin

Description

Video for Linux is a video capture application programming interface(API) and library for Linux. The library supports many USB web cams, TV tuners as well as other devices and is the common way to access multimedia devices under Linux. The v4l2caps plugin uses the Video for Linux API to capture frames from compatible hardware devices and stores each frame into CAPS. Available resolutions, pixel formats and other parameters depend on the used device. See the manual of the hardware manufacturer for more details. The capture process of the plugin gets a frame in a given sampling interval. For each frame a new ANY packet is created which uses the sampling time of the frame as start and end time for the packet. In addition the format of the packet is set to the selected pixel format. Frame drops may occur when the storage system is not fast enough to handle incoming data.

Examples

To capture 15 images per second (the maximum number of images depends on your hardware) and store the output into CAPS use:

$ v4l2caps -s SW.HMA.317.CAM --interval 15/1

Configuration

etc/defaults/global.cfg
etc/defaults/v4l2caps.cfg
etc/global.cfg
etc/v4l2caps.cfg
~/.seiscomp/global.cfg
~/.seiscomp/v4l2caps.cfg

v4l2caps inherits global options.

Note

Modules/plugins may require a license file. The default path to license files is @DATADIR@/licenses/ which can be overridden by global configuration of the parameter gempa.licensePath. Example:

gempa.licensePath = @CONFIGDIR@/licenses
host

Type: string

Data output host Default is localhost.

port

Type: uint

Data output host Default is 18003.

streamID

Type: string

Stream ID to use, format is [net.sta.loc.cha]

resolution

Type: string

Resolution to use

outputFormat

Type: string

Output format to use [rgb, jpg]

outputQuality

Type: int

Output quality to use [0-100] Default is 100.

interval

Type: uint

Sampling interval to use, format is [Denominator/Numerator]

pixelFormat

Type: string

Pixel format to use, expected as four character code[ABCD]

count

Type: uint

Number of frames to grab Default is 0.

skip

Type: uint

Number of frames to skip Default is 0.

bufferSize

Type: uint

Size (bytes) of the internal buffer to keep still unconfirmed packages Default is 1048576.

device

Type: string

Video device name Default is /dev/video0.

io

Type: uint

I/O method. 0: Use read function, 1: Use memory mapped buffers Default is 1.

Command Line

-b, --buffer-size arg

Size (bytes) of the internal buffer to keep still unconfirmed packages

-c, --count arg

Number of frames to grab

--config arg

Path to configuration file

-d, --device arg

Video device name

--dump arg

Dump output to file

-f, --pixel-format arg

Pixel format to use, expected as four character code[ABCD]

-F, --output-format arg

Output format to use [rgb, jpg]

-H, --host arg

Data output host

-h, --help arg

Print help

--info arg

Print device info

-i, --interval arg

Sampling interval to use, format is [Denominator/Numerator]

--io arg

I/O method. 0: Use read function, 1: Use memory mapped buffers [default]

-p, --port arg

Data output port

-q, --output-quality arg

Output quality to use [0-100]

-r, --resolution arg

Resolution to use

-s, --stream-id arg

Stream ID to use, format is [net.sta.loc.cha]

-S, --skip arg

Number of frames to skip