When the manual method is selected a video player will be shown:
Use this option when using video that is either from a stationary video camera, or when subject matter is not conducive to Automatic Video Frame Extraction. Note that the ‘Extract frames to Image Sequence’ option is only enabled when manually extracting frames, as an Image Sequence is inherently based on stationary camera images (Automatic extraction cannot extract frames from a video taken from a stationary video camera).
The player allows you to navigate through the video using the controls or scroll bar. Press the ">" button to play/pause the video. The ">" button toggles between ">" and "||". The "|<" rewinds the video to the start, ">|" to end, "<<" backs up one frame, ">>" moves forward one frame. The "<<" and ">>" can be used to reselect nearby frames if motion blur is present. The current position in seconds updates when navigating through the video.
Click the Save Frame button to store a frame and add it to your project (while playing or while paused).
You can also extract frames based on the desired interval of frames or seconds. Note that no checking is done internally to determine whether the frames are in focus, so this may not produce an optimal set of photos.
Be sure to select enough frames so that there is suitable overlap (see SmartPoints Photo Requirements and DSM Photo Requirements) but not so many that your project is unnecessarily large.
Note that manually extracted video frames can be automatically extracted to an Image Sequence using the option on the Video Extraction dialog.