When selecting a video of one of the supported formats a prompt to choose the Extraction Method and Type is displayed:
First select the Extraction Method then the Extraction Type. Extracting frames to Image Sequence is only available when using the Manual Extraction method, and is only useful for video from a stationary video camera.
Regardless of whether frames are extracted using the Automatic or Manual approach, frames are stored in a "frames" sub-folder of the project/video, and the following image frame file naming convention is used:
"XXXX_f-YY_t-ZZ_FFfps.jpg", where XXXX is the video file name, YY is the position frame number, ZZ is the position of frame in seconds, and FF is the frame rate of the video file.