Improve retroplayer playback

Hi,

retroplayer seems to work great on my OdroidC2 with relkai nightly builds, except one little annoyance:
scrolling seems to be not 100% smooth. I don’t notice it in slower games, but you can recognize it easily in fast-paced games, such as super mario for the snes (just run around in the first level).
It doesn’t seem to be an emulator issue, as I have tried all of them (SNES + NES).
I have also tried all kinds of refresh rates and resolutions, even though it exactly looks like choppy video playback due to the wrong refresh rate, it didn’t help.
Framerate seems to be very stable (according to the debug overlay)
Any idea?