IMHO the bitrate meter sometimes displays strange values...
How strange?
The latest patch (which will probably break shortly) does not contain
this fix - multiple recordings in a row will display nonsense 'remaining time'.
The other issue I'm aware of is that recorded file size info (and current bitrate) only updates when a chunk of movie data is passed to APENDSTRM (a chunk is 3 MB or something close).
Can you add 120f too? (No rush)