Page 30 of 60
The camera can also do scaling to take a source image and
“
fit it into
”
a destination region. For example, to
ask for a scaled-up version of a stream of 320 by 240 pixels, 10 pixels to the right and 20 pixels down from
the upper left corner of the full image, use the URL:
http://<camera_ip>/now.jpg?snap=spush&wl=10&wt=20&wrw=320&wrh=240&wdw=640
This will resample the image using bicubic interpolation and deliver it as a 640x480 stream
6.3.
Serverpush stream with embedded motion data
The simplest mechanism to get motion data from the camera is to request embedded motion meta data in the
serverpush stream. To enable the status information, the serverpush URL request should include the
“
pragma=motion
”
string, as shown in this sample URL:
http://<camera_IP>/now.jpg?snap=spush&pragma=motion
This pragma will return the raw motion detection from each frame. As long as motion continues to occur, this
option will continue showing the motion indication for each frame of video data.
6.4.
Serverpush stream with embedded trigger data
If requested, the camera can include both motion and trigger status information in the image data it serves in a
serverpush stream. To enable the status information, the serverpush URL request should include the
“
pragma=trigger
”
string, as shown in this sample URL:
http://<camera_IP>/now.jpg?snap=spush&pragma=trigger
Each HTML image header will then contain a line of the form
“
Pragma: trigger=<reason>,
”
where reason can
be one of the following strings:
“none” - no trigger event occurred.
“input” - the I/O relay was triggered.
“timer” - a periodic (time-based) trigger occurred.
“motion” - the motion detection software triggered the event. The pragma line will also include
the number(s) of the motion detection windows that detected the motion. Note that this will
only show the motion pragma in the “first” frame of the motion sequence. The trigger will
be re-enabled when ????
“test” - a one-time trigger occurred. A user ran either the
TEST TRIGGER
command or the
equivalent
OID.
For example, a sample image stream that detected motion in motion windows 2 and 3 might contain:
Pragma: trigger=none
Pragma: trigger=none
Pragma: trigger=motion 2 3
Pragma: trigger=none
The first image in the serverpush stream will always have
pragma: trigger=none.
