To make it possible to perform Forensic Search of the archives of a video camera, the following conditions must be met:
Video meets the requirements.
- There are video stream recordings from the desired video camera in the archive (see Binding a camera to an archive).
- There are metadata recordings from this video stream in the object trajectory database. Metadata can be generated by C-Werk (see Object Tracker, Facial Recognition) or received from a video camera (see Configuring Built-In Detectors).
- The user has the appropriate permissions.
This section contains information on how to configure the C-Werk software package to satisfy these conditions.
Video suitability for Forensic Search of recorded video (requirements)
For Forensic Search of recorded video to be possible, video must meet the same requirements as those applied to video for detection tools (see Requirements for the cameras).
In addition, the minimum and maximum detectable object speeds in video are related to the camera's frame rate.
The maximum detectable speed depends on the size of the object. The following table shows the relationship between the maximum detectable speed and the frame rate for typical objects (people and cars):
Frame rate
Maximum detectable speed for people
Maximum detectable speed for cars
6 fps
5 km/hr
40 km/hr
12 fps
10 km/hr
85 km/hr
25 fps
20 km/hr
170 km/hr
So if it is necessary, for example, to detect people moving at speeds of up to 10 km/hr, it is sufficient to record at 12 fps.
- The minimum object speed should be such that the object moves at a rate of at least 1 pixel per frame.
Turning on the video stream metadata recording
Select Yes in the Record object trajectories list to enable recording metadata in the database for the corresponding detector (Object Tracker, face detector, built-in detector).
Note
Information on configuring storage of metadata is provided in the section titled Configuring storage of the archive, system log, and metadata
Configuring user permissions for Forensic Search in archive
You need Live/Archive, Live/Archive/Control or Live/Archive/Control/Configure permissions for a video camera to perform a smart search (see Configuring user permissions).
