Video API Extensions legacy
Template:Ru=Video API Extensions
Given realization of Video API has a number of opportunities which are absent in standard Axis Video API.
Contents
Extensions enabling
By default the Video API extensions are blocked. For unblocking it is necessary to establish a corresponding variable:
http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ElphelExtensions.Enabled=yes
Obtaining of static and dynamic images
The standard interface for the static and dynamic images obtaining in JPEG and MJPEG formats is have a few additional parameters.
e_dcm_hor | - | horisontal decimation (resolution/image size reduction) |
e_dcm_vert | - | vertical decimation (resolution/image size reduction) |
e_bin_hor | - | horizontal binning (sensitivity for lower resolution) |
e_bin_vert | - | vertical binning (sensitivity for lower resolution) |
e_woi_width | - | sensor active window width (before decimation) |
e_woi_height | - | sensor active window height (before decimation) |
e_woi_left | - | sensor active window left margin (before decimation) |
e_woi_top | - | sensor active window top margin (before decimation) |
e_virt_width | - | virtual frame width |
e_virt_height | - | virtual frame height |
e_fliph | - | flip (mirror) image horizontally (uses in-sensor capabilities) |
e_flipv | - | flip (mirror) image vertically (uses in-sensor capabilities) |
e_color | - | consider sensor to be the color one, if not - skip Bayer color filters processing |
e_quality | - | JPEG Quality (%) |
Examples
Example of the static image obtaining with using the next parameters:
http://192.168.0.9/axis-cgi/jpg/image.cgi?e_dcm_hor=2&e_dcm_vert=2&e_woi_width=1000&e_woi_height=900&e_woi_left=600
Example of the dynamic image (MJPEG) obtaining with using the next parameters:
http://192.168.0.9/axis-cgi/mjpg/video.cgi?e_dcm_hor=2&e_dcm_vert=2&e_woi_width=1000&e_woi_height=900&e_woi_left=600
You can play this videostream, for example, by using the MPlayer (more detailed description see at Using Mplayer With Video API.Ru):
$mplayer -demuxer lavf "http://192.168.0.9/axis-cgi/mjpg/video.cgi?e_dcm_hor=2&e_dcm_vert=2&e_woi_width=1000&e_woi_height=900&e_woi_left=600&bogus.mjpg"
If any from parameters is not specified, the default values are used. You can find these values at the address:
http://192.168.0.9/axis-cgi/admin/param.cgi?action=list&group=ImageSource.I0.Sensor
Note: All API extensions have the prefix "E_".
You can change the default value by standard way for Axis Video API. For example:
http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ImageSource.I0.Sensor.E_DcmHor=1
Obtaining the information about the system condition and default values
For obtaining the information about the system condition variable you must use the next path:
http://192.168.0.9/axis-cgi/admin/param.cgi?action=list&group=ImageSource.I0.E_CurrentState
In an addition to the obtaining of the standard "rfc" format there is the obtaining in XML format also. You must use the responseformat parameter for it. For example:
http://192.168.0.9/axis-cgi/admin/param.cgi?action=list&group=ImageSource.I0.E_CurrentState&responseformat=xml
Note. If the responseformat not specified or specified incorrect, will be used the default value of "rfc".
Video streaming RTP/MJPG and RTP/Theora
The Elphel cameras can transfer the video stream by RTP protocol.
RTP/MJPG
RTP/Theora
Exposure control
The Elphel cameras support the standard and advanced exposure control interface. About the standard settings see First_Acquaintance_With_Video_API.Ru
For autoexposure enabling is necessary to use the following command:
http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ImageSource.I0.Sensor.Exposure=auto
Enabling the manual control of exposure:
http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ImageSource.I0.Sensor.Exposure=manual
Obtaining the exposure state:
http://192.168.0.9/axis-cgi/admin/param.cgi?action=list&group=ImageSource.I0.E_CurrentState.E_Exposure
Window settings:
http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ImageSource.I0.Sensor.E_Exposure.E_WinWidth=30&ImageSource.I0.Sensor.E_Exposure.E_WinHeight=45&ImageSource.I0.Sensor.E_Exposure.E_WinLeft=10&ImageSource.I0.Sensor.E_Exposure.E_WinTop=20
Exposure max.values:
http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ImageSource.I0.Sensor.E_Exposure.E_Max=3000&ImageSource.I0.Sensor.E_Exposure.E_OverMax=30