[linux-audio-dev] [ann] unmatched - a LADSPA amp tone

[nikodimka]

>> You can calculate your tranformation for the input signal S(x_i) once
>> And the same transformation for S(x_i)+1 again.
>
>Won't that just give you the gradient at point x_i, ie. d/dt(S)?

yes.

>We are talking about frequency domain aliasing here, 

oh yeah i see. sorry.

> which is when you
>generate partials that would be above the nyquist frequencyi, so they get
>reflected down into low frequencies. It is not directly related to the
>differential of the signal, though a high differential is often indicative
>of an aliasing problem.
>
>Typically you prevent audio aliasing by generating the waveform in a way
>so that it contains no partials above nyquist, or by generating it at a
>sufficiently high sample rate that there are none, then decimating down. 

but you can do the pretty same trick for the frequencies:
take two different numbers with no common divisors 
(or just a pair of prime numbers) as sampling rates
and see how the output signal changes.
The difference give you some linear combination of aliased frequencies.



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