[SoX-users] Determine RMS Level in Sample Value (as opposed to in dB)

[Mike C. <mie...@gm...>]

Hi all,

I'm wondering if it is possible to get SoX to calculate a wav file's
RMS as sample value.  For example, given a 16-bit linear signed wav
file, I can run the command:

sox -V3 myaudio.wav -n stats

Which outputs a bunch of statistics including "RMS lev dB", e.g.:
    RMS lev dB    -35.59

I think I can convert "RMS lev dB" to "RMS lev Value" by:
    ((rms_lev_dB / 20) ^ 10) * full_scale_digital_sample = rms_lev_value

Which for my example data (16-bit linear signed, -35.59 rms_lev_dB)
would yield 550:
    ((-35.59 / 20) ^ 10) * 32,768 = _550_

(full_scale_digital_sample = 2^sample_size_in_bits / 2 = 2^16/2 = 32,768)

I'd prefer if SoX could output this value (e.g. 550) directly, rather
than my having to convert the dB value every time.   I can get the
commercial product Sound Forge to give me this value via Tools ->
Statistics, then changing the level format to "Sample Value", so I
know it's not a completely obscure request.  I suppose I could write a
wrapper around SoX to convert the value on the fly, but if it's
already built in I'd like to save myself the trouble.

thanks!
-Mike