If the video is variable frame-rate, then the only way is to read the frames one-by-one, checking the time associated with the video object at each frame, and saving only the frames associated with times you are interested in.
If the video is fixed frame-rate then you can use the frame rate and the times to calculate starting and ending indices and you can ask for that range of frames.
VideoReader is recommended for this purpose, but you might be able to use the older mmreader as well.
