[SoX-users] Problem obtaining frequent RMS measurements

[Aaron \Caustik\ R. <ca...@gm...>]

I'm attempting to split an input audio file into 3 bands, and measure the
RMS for each band at 50ms intervals.

Seems easy enough with the filters sox provides, however for some reason I
can't seem to actually get 50ms resolution. I get about half of that
(~100ms). Here's the calls I'm making:

./sox decoded.wav -n lowpass 500 stats trim 0 0.05 : restart 2>
low-stats.txt
./sox decoded.wav -n bandpass 1000 1000 stats trim 0 0.05 : restart 2>
mid-stats.txt
./sox decoded.wav -n highpass 2000 stats trim 0 0.05 : restart 2>
high-stats.txt

The window for 'stats' is quoted as 50ms. I attempt to send trim to 50ms,
and use restart to force stats to frequently spew it's data.

Is there something I'm doing wrong here? Is there a better way to pull this
off?

caustik