Subject: [ecasound] filter testing
From: Kai Vehmanen (firstname.lastname@example.org)
Date: Thu Sep 16 1999 - 23:33:19 EEST
Ok, I took a sample of random noise and tested all ecasound's
filters. I used snd for the fft analysis.
-ef1 Resonant bandpass. Not a good start. This is definately
-ef3 Resonant lowpass. This is one the most complex effects of
ecasound... and also among the working ones.
-efb Bandpass. Appears to work as expected.
-efh Highpass. Seems to work. -efh:22050 produces silence as it
-efi Inverse comb. Works as expected.
-efl Lowpass. Works, but isn't as aggressive as ef3. -efl:0
-efr Bandreject. -efr:11025,22050 results in a empty fft as
-efs Resonator (=resonant bandpass). Seems to work fine.
Not very accurate though.
So most of them work as expected. I'll try to fix -ef1.
Btw; efb, efh, efl and efr are all based on the same
filter equation (2nd order butterworth filters). Due to
this, they're also equally accurate. Anyway, there will probably
be a few new filters in ecasound 1.6.x. For more info about
planned features of 1.6.x and 1.7.x, see
-- Kai Vehmanen <email@example.com> -------- CS, University of Turku, Finland . http://www.wakkanet.fi/ecasound/ - linux audio processing . http://www.wakkanet.fi/sculpscape/ - ambient-idm-rock-... mp3/ra/wav
This archive was generated by hypermail 2a24 : Sat Sep 25 1999 - 19:41:13 EEST