alsa and sox questions

[Geoff Shang]

Hi:

Unless your card is noisy,  getting the exact volume is not that big of a
deal, as you can normalise it later.  To do this, do the following:

1.  Record your material at a safe level (i.e. at one where the levels do
not clip).

2.  Assuming you called it recording.wav, do the following:

sox recording.wav -e stat

This will print a number of statistics about the file.  The final one will
look something like this:

Volume adjustment: 1.000

If the number is above 1.0, it means that the file can be amplified without
it clipping.  The above example is for a file that is already as loud as it
can go.

3.  Now do the following:

sox -v <volume adjustment> recording.wav normalised_recording.wav

Where <volume adjustment> is the value in the output as shown above.

This will make a copy of your recording that can be as loud as possible
without clipping (i.e. it is normalised).

Geoff.


-- 
Geoff Shang <gshang at uq.net.au>
ICQ number 43634701

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