Bug: wrong transcript duration displayed

[tamsingreen]

A user (Andrew Butterworth) reported a bug with a media upload for a file of 1h7m duration showed a transcription estimate of 7m. (the file was an mp4 if that makes a difference).

Needs further investigation to see if this just happens with clips over an hour long or if there are any other factors.

[allishultes]

Looks like this would only happen with clips over an hour long - I believe this is the problematic function, which can be replaced by this. On it.