Configuring VMD

To configure a VMD:

1. To record Motion mask to archive, set Yes for the corresponding parameter (1).
   
2. The Video Motion Detection tool can receive tracking metadata generated by the Motion mask. The metadata are recorded into the database by default. To disable, select No in the Record objects tracking (2).
3. If a camera supports multistreaming, select the stream for which detection is needed (3). Selecting a low-quality video stream allows reducing the load on the Server.

4. In the Alarm end delay field, set a value in seconds for the time interval within which the detection tool remains triggered after motion stops (4). If motion is re-detected within this interval, no new event will be created.

5. To reduce false alarms rate from a fish-eye camera, you have to position it properly (5). For other devices, this parameter is not valid.

6. If necessary, enable the video stream grooming (6). In this case, only the I-frames will be decoded.

   Important

   This setting applies to all codecs. If a codec has keyframes and p-frames, the keyframe is decoded no more often than every 500 milliseconds. For the MJPEG codec, each frame is considered to be I-frame.

   This feature reduces the Server load but, as can be expected, negatively impacts the quality of detection.

   This setting should be activated on "blind" Servers (Servers that do not display video) on which it is necessary to perform detection.

7. Select a processing resource for decoding video streams (7). When you select a GPU, a stand-alone graphics card takes priority (when decoding with NVidia NVDEC chips). If there's no appropriate GPU, the decoding will use the Intel Quick Sync Video technology. Otherwise, CPU resources will be used for decoding.

8. Set the frame rate value for the detection tool to process (8). This value should be in the range [0,016; 100]. 

9. The VMD analyzes differences between the current frame and the static background (11, 12). Depending on a particular scene, we recommend the following sensitivity values for contrast and size:

   1. Maximum sensitivity (street scenes where target objects are smaller):

      1. Sensitivity: contrast = 16.

      2. Sensitivity: size = 10.

   2. Medium sensitivity (default values for generic scenes):

      1. Sensitivity: contrast = 12.

      2. Sensitivity: size = 9.

   3. Low sensitivity (indoor cameras with an average distance to object of ca. 4m):

      1. Sensitivity: contrast = 8.

      2. Sensitivity: size = 8.

         For your convenience with setting sensitivity value, in the preview window you can see the Motion mask. To disable it, select No in the Motion mask (9) field.

         
         If there is motion, but it does not exceed the threshold value (because of the detection sensitivity), the mask cells are colored green. If motion triggers VMD, the cells turn red.

10. To get tracked objects and their parameters (percentage of the FoV width/height, color) displayed in the Preview window, select Yes in the Object tracking field (10). 

11. By default, VMD (video motion detection) covers the entire FoV. In the FoV, you can set exclude areas – closed areas, inside of which you want no detection.
    Exclude area are created similar to scene analysis configuration (see Setting General Zones for Scene analytics detection tools). 

12. Click Apply.

VMD configuration is now complete.