如何在MATLAB中创建一个用于播放、暂停、快进和回放视频的GUI ?

I am a newbie to MATLAB. I am trying to create a GUI to play, pause, fast forward and rewind an avi video frame by frame. At the moment I can play and pause the video, via a toggle button, but when I press play again the video plays from frame zero. I realise I need to store the frame number to be used the next time I press play but I don't know how to do this. Any help would be much appreciated. I realise there is an implay option in MATLAB but I have some other code to implement which I have already got right and that is why I want to create my own GUI. Below is the code to pause/play the video.I am a newbie to MATLAB. I am trying to create