Confusing error message with incorrect timecode input

[Breakthrough]

Specifying timecodes as 1:00 on the CLI seems to break things. It should at least print a graceful error message, but perhaps we should allow this to be used as a timecode indicating 1 minute

[wjs018]

Maybe something as simple as parsing the number of : characters and inferring that it is MM:SS.nnn if there is just a single :?