First thoughts would be, [info~ /yourbuffername/] will output total file size in [buffer~] and [groove~] outputs a 0. to 1. ramp over the duration of the loop, so multiply this ramp by file size; also, look at the [waveform~] object.

like this:

Brendan

I've looked into waveform~. I will check out the info~ suggestion and see what I can make happen. Thanks.

here's the same patch, with added [waveform~]

Perfect. Exactly what I was looking for. Thanks!

and what if you wanted to change the min and max playback values? simple math?

easier to simply impose line over waveform at that point? thanks