Starts recording and outputs to the specified file. This method is only valid when the LibType property is "OPENCV".

The fps parameter specifies the frame rate (number of frames per second). For example, if you specify 1fps, one frame will be recorded per second. Specifying 0 will set it automatically (in automatic settings, the frame rate will match the frame rate of the video file when playing a video file, and 2fps for cameras). Note that if you set fps to less than 0.5, it will be forcibly set to 0.5fps. fps affects the smoothness of the video and the file size. Adjust the value specified for fps based on the acceptable file size and the performance of the camera itself (frame rate, etc.). For example, if the playback frame rate of the camera is 1fps (once per second), even if you specify 25fps for recording, the same image will be saved repeatedly, and the file size will be unnecessarily large.