Video resolution has to be the same as the screen resolution of your Tomtom GPS.

For your information, TomTom ONE screen resolution is 320*240 while TomTom XL or TTGO screen resolution is 480*272.

To do that, you can use mencoder command line tool.

You can also use software as SUPER or |PocketDivxEncoder.

Posts about encoding settings on Tomplayer forum