Documentation for C-Werk 2.0.

Previous page Video requirements for tampering detection  Service Audio Detection Tools Next page

Video requirements for tampering detection

To set up the Tampering detection, do the following:

  1. If a camera supports multi-streaming, select the stream for which detection is needed. Selecting a low-quality video stream allows reducing the load on the Server.

  2. The default setting for all detection tools is Decode only key frames. In this case, only key frames are decoded. To disable the decoding of key frames, select No in the corresponding field.

    Attention!

    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.

    For the MJPEG codec, each frame is considered a key frame.

  3. Select a processing resource for decoding video streams. 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.

  4. Set the frame rate value for each detection tool to process. This value should be in the range [0.016, 100].

    Attention!

    Frames processed per second and Decode only key frames parameters are correlated.

    If no local Clients are connected to a Server, the following rules are set for remote Clients:

    • If the interval between consecutive I-frames exceeds the value specified in the Frames processed per second field, the detection tool will process I-frames.
    • If the I-frame frequency is lower than the value specified in the Frames processed per second field, the detection tool will use the set value.

    If at least one local Client connects to the Server, the detection tool is forced to use the set value. After the local Client disconnects, the indicated rules become valid again.

  5. Select one or more analyzes to be applied to the video image. If you select Blurred image analysis, Compression artifacts analysis, Image noise analysis, Quality degradation analysis, or Scene change analysis, configure the following parameters:
    1. Event duration to trigger detection (sec) is the maximum time of the event duration after which the detection tool will trigger. But, the detection tool can trigger even earlier if the algorithm undoubtedly determines the noise. If the detection tool does not trigger after the event duration time expires, it means that the corresponding image defect was not detected with the specified detector sensitivity.
    2. Sensitivity of detection tool operation in standard units from 0 to 100.
  6. To save settings, click the Apply button.

Tampering detection is now configured.