245 lines
4.2 KiB
ReStructuredText
245 lines
4.2 KiB
ReStructuredText
.. highlight:: rst
|
|
|
|
.. _v4l2caps:
|
|
|
|
########
|
|
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:
|
|
|
|
.. code-block:: sh
|
|
|
|
$ v4l2caps -s SW.HMA.317.CAM --interval 15/1
|
|
|
|
|
|
|
|
Module Configuration
|
|
====================
|
|
|
|
| :file:`etc/defaults/global.cfg`
|
|
| :file:`etc/defaults/v4l2caps.cfg`
|
|
| :file:`etc/global.cfg`
|
|
| :file:`etc/v4l2caps.cfg`
|
|
| :file:`~/.seiscomp/global.cfg`
|
|
| :file:`~/.seiscomp/v4l2caps.cfg`
|
|
|
|
v4l2caps inherits :ref:`global options<global-configuration>`.
|
|
|
|
.. note::
|
|
|
|
Modules/plugins may require a license file. The default path to license
|
|
files is :file:`@DATADIR@/licenses/` which can be overridden by global
|
|
configuration of the parameter :confval:`gempa.licensePath`. Example: ::
|
|
|
|
gempa.licensePath = @CONFIGDIR@/licenses
|
|
|
|
|
|
|
|
.. confval:: host
|
|
|
|
Default: ``localhost``
|
|
|
|
Type: *string*
|
|
|
|
Data output host
|
|
|
|
|
|
.. confval:: port
|
|
|
|
Default: ``18003``
|
|
|
|
Type: *uint*
|
|
|
|
Data output host
|
|
|
|
|
|
.. confval:: streamID
|
|
|
|
Type: *string*
|
|
|
|
Stream ID to use, format is [net.sta.loc.cha]
|
|
|
|
|
|
.. confval:: resolution
|
|
|
|
Type: *string*
|
|
|
|
Resolution to use
|
|
|
|
|
|
.. confval:: outputFormat
|
|
|
|
Type: *string*
|
|
|
|
Output format to use [rgb, jpg]
|
|
|
|
|
|
.. confval:: outputQuality
|
|
|
|
Default: ``100``
|
|
|
|
Type: *int*
|
|
|
|
Output quality to use [0\-100]
|
|
|
|
|
|
.. confval:: interval
|
|
|
|
Type: *uint*
|
|
|
|
Sampling interval to use, format is [Denominator\/Numerator]
|
|
|
|
|
|
.. confval:: pixelFormat
|
|
|
|
Type: *string*
|
|
|
|
Pixel format to use, expected as four character code[ABCD]
|
|
|
|
|
|
.. confval:: count
|
|
|
|
Default: ``0``
|
|
|
|
Type: *uint*
|
|
|
|
Number of frames to grab
|
|
|
|
|
|
.. confval:: skip
|
|
|
|
Default: ``0``
|
|
|
|
Type: *uint*
|
|
|
|
Number of frames to skip
|
|
|
|
|
|
.. confval:: bufferSize
|
|
|
|
Default: ``1048576``
|
|
|
|
Type: *uint*
|
|
|
|
Size \(bytes\) of the internal buffer to keep still unconfirmed packages
|
|
|
|
|
|
.. confval:: device
|
|
|
|
Default: ``/dev/video0``
|
|
|
|
Type: *string*
|
|
|
|
Video device name
|
|
|
|
|
|
.. confval:: io
|
|
|
|
Default: ``1``
|
|
|
|
Type: *uint*
|
|
|
|
I\/O method. 0: Use read function, 1: Use memory mapped buffers
|
|
|
|
|
|
|
|
|
|
Command-Line Options
|
|
====================
|
|
|
|
|
|
.. _:
|
|
|
|
.. option:: -b, --buffer-size arg
|
|
|
|
Size \(bytes\) of the internal buffer to keep still unconfirmed packages
|
|
|
|
.. option:: -c, --count arg
|
|
|
|
Number of frames to grab
|
|
|
|
.. option:: --config arg
|
|
|
|
Path to configuration file
|
|
|
|
.. option:: -d, --device arg
|
|
|
|
Video device name
|
|
|
|
.. option:: --dump arg
|
|
|
|
Dump output to file
|
|
|
|
.. option:: -f, --pixel-format arg
|
|
|
|
Pixel format to use, expected as four character code[ABCD]
|
|
|
|
.. option:: -F, --output-format arg
|
|
|
|
Output format to use [rgb, jpg]
|
|
|
|
.. option:: -H, --host arg
|
|
|
|
Data output host
|
|
|
|
.. option:: -h, --help arg
|
|
|
|
Print help
|
|
|
|
.. option:: --info arg
|
|
|
|
Print device info
|
|
|
|
.. option:: -i, --interval arg
|
|
|
|
Sampling interval to use, format is [Denominator\/Numerator]
|
|
|
|
.. option:: --io arg
|
|
|
|
I\/O method. 0: Use read function, 1: Use memory mapped buffers [default]
|
|
|
|
.. option:: -p, --port arg
|
|
|
|
Data output port
|
|
|
|
.. option:: -q, --output-quality arg
|
|
|
|
Output quality to use [0\-100]
|
|
|
|
.. option:: -r, --resolution arg
|
|
|
|
Resolution to use
|
|
|
|
.. option:: -s, --stream-id arg
|
|
|
|
Stream ID to use, format is [net.sta.loc.cha]
|
|
|
|
.. option:: -S, --skip arg
|
|
|
|
Number of frames to skip
|
|
|
|
|