[PATCH v2 0/1] MR10056: dsound: Use a better FIR filter generated with the Parks-McClellan algorithm.

[Anton Baskanov (＠baskanov)]

The new filter provides a 98.5 dB stopband rejection and doesn't attenuate frequencies below 20 kHz (assuming 44.1 kHz sampling rate).

![magnitude](/uploads/e0947573942210102f85bc11082c1380/magnitude.png){width=900 height=403}

![sweep.wine.upstream](/uploads/411cb840ed5f7117a669e1a729101d0f/sweep.wine.upstream.png){width=675 height=356}

![sweep.wine.pm-fir](/uploads/b2f6d669c1bb62c70d6a4a725cb06aa8/sweep.wine.pm-fir.png){width=675 height=356}

P.S.: Thanks to Matteo Bruni for providing the test tools.

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  v2: dsound: Use a better FIR filter generated with the Parks-McClellan algorithm.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10056