Table 2 Pre-implemented operators for multimedia data (partial.)

The “File Input” operator reads a video file from a specific device as the data source.

The “Real-time Stream Input” operator binds a specific device using the RTSP or RTMP protocol and outputs the real-time data stream to subsequent operators.

The “USB Camera Input” operator reads and outputs data from a specific USB camera.

The “Encode” operator encodes the original video stream into a specific format, e.g. H.264, H.265, JPEG.

The “Decode” operator decodes the encoded video or JPEG images to obtain raw video information.

The “Mux” operator encapsulates the encoded video into a specific format, e.g. FLV, MP4.

The “Demux” operator parses the input data into encoded video.

The “Resolution“ operator transforms the resolution of the input video stream into a specific setting, e.g. 1280*720.

The “Frame Rate” operator limits the maximum number of frames per second of the input video stream.

The “Region Of Interest” operator specifies a region in the input image or video stream, so that subsequent “Apply Model” operators will only make inferences towards the specified region in the images. This avoids unnecessary processing and saves resources.

The “Apply Model“ operator binds a specific AI model, and the input video stream is filtered somehow to get the model input. Moreover, the results returned by the model are saved in the output video stream, such as drawing recognition frames.

The “File Output” operator saves the input video stream as a local file.

The “Alert” operator treats its inputs as alerts and sends them to the cloud.