There are some very short video snippets that need to be analyzed (one second or less in duration), and I cannot get to the pause button in time after selecting the video file so the player just closes.
However, I need to be able to disable the auto-play function and have not been able to locate how to do that. SMPlayer is one of the better possibilities I have found, and it appears to work quite well for frame-by-frame playback and analysis that is needed. So although it would be more inconvenient to implement, I have been looking for standalone players that can supplement the application.
For the apparently most common Chrome browser in particular, to date I have not been able to achieve needed frame-by-frame playback capability directly in my web application under development (though we can get the needed functionality with other browsers like Firefox and Edge).