Re: which is better / more effective

James Trammell <[email protected]> writes:

> Hi,
>
> Myself being new to SoX and unfamiliar with the code, my advice would be to
> try all three ways, then run a few tests to find any bad behavior. Trust,
> but verify.
>
> file A = one call with several switches.
> file B = several calls with one switch.
> file C = several calls with one switch, piped together.
>
> Null test
>
> Invert the phase of B, combine with A, listen for problems.
> Invert the phase of C, combine with A, listen for problems.
> Invert the phase of C, combine with B, listen for problems.
>
> Spectrograph
>
> I would also load files A, B and C into spectrograph software to see what
> information is present at the very bottom bits of the bit depth.
>
> Try the conversions without dither to see if the spectrographs show
> different levels of truncation noise.

Before going to all that trouble, just compare the three files and see
if they differ at all.  If the output precision is less than 24 bits, it
will have dither automatically applied (unless disabled with the -D flag),
so for such a test the -R flag should be used to select a fixed seed for
the dither RNG.

-- 
Måns Rullgård

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