Not sure what you mean - the C3 media player definitely doesn’t need a “constant midi signal” if you use the right kind of binding. I sometimes use a standard hold pedal to play / pause a song - your PS-3 is the same kind of pedal (sends one MIDI controller value when pressed and another when released).
So the kind of binding you need to play/pause would be this:
The difference: “No Edge Button” triggers on any non-zero controller value, whilst “Button” will only trigger when coming from a value < 64 to one > 64. With a normal setting of your foot switch, it should normally send a controller value of 127 when pressed and one of 0 when released.
For the binding, I’ve used a CC 64, but of course you can use any other controller that your pedal may send. And in my pictures, I’ve used a “play/pause” binding, but there is also a “play/stop” binding that will reset your song to zero whenever it is stopped.
Now whenever you press and release the pedal, playback will start; on the next press, it will pause or stop.
@terrybritton: you’ll see in these pictures that there IS a toggle option for play/pause as well as for play/stop.
@dave_dore: I guess the issue about “short midi signals” may not be about switch bounce, but mainly about the fact that the pedal is momentary and not a toggle switch. But starting and pausing (or stopping) the media player with a momentary pedal is perfectly feasible using the binding above.