Re: [SoX-users] To normalize volume level in a file

[Jan S. <ha...@st...>]

> And I can not understand how the voice is changed. I use sox C:\sox-14-3-2\musteri.au --show-progress -n stat. And the output is:
> 
> 
> ==============================================================
> Input File     : 'C:\sox-14-3-2\musteri.au'
> Channels       : 1
> Sample Rate    : 8000
> Precision      : 14-bit
> Duration       : 00:01:41.40 = 811200 samples ~ 7605 CDDA sectors
> File Size      : 811k
> Bit Rate       : 64.0k
> Sample Encoding: 8-bit u-law
> 
> In:100%  00:01:41.40 [00:00:00.00] Out:811k  [ -====|====- ]        Clip:0
> Samples read:            811200
> Length (seconds):    101.400000
> Scaled by:         2147483647.0
> Maximum amplitude:     0.378784
> Minimum amplitude:    -0.378784
> Midline amplitude:     0.000000
> Mean    norm:          0.009511
> Mean    amplitude:     0.000011
> RMS     amplitude:     0.049504
> Maximum delta:         0.196045
> Minimum delta:         0.000000
> Mean    delta:         0.003645
> RMS     delta:         0.017613
> Rough   frequency:          453
> Volume adjustment:        2.640
> Done.
> 
> ================================================================
> 
> 
> How I understand that normalize our file?

On a scale from -1 to +1, the minimal/maximal amplitude present in your
file is about +/- 0.378784; so the volume can be adjusted by a factor
of 2.640 without introducing clipping. That's what normalize means.

You need to read the man page, really. It explains everything in
detail, and teaches you a thing or two about digital audio in general.

	Jan