Skip to content

dcblock2

Implements a DC blocking filter with improved DC attenuation.

Syntax

ares dcblock2 ain [, iorder] [, iskip]

Initialization

iorder -- filter order, minimum 4th order, defaults to 128.

iskip -- set to 1 to skip initialization (defaults to 0).

Performance

ares -- filered audio signal

ain -- input audio signal

📝 Note

Using a value for iorder less that ksmps will not reduce DC offset efficiently.

Examples

The result can be viewed in a graphical audio editor program like audacity. audacity is available for Linux, Windows, and the MacOS and may be downloaded from http://audacity.sourceforge.net.

Here is an example of the dcblock2 opcode. It uses the file dcblock2.csd, and drumsMlp.wav.

Example of the dcblock2 opcode.
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
-odac     ;;;RT audio out
;-iadc    ;;;uncomment -iadc if RT audio input is needed too
; For Non-realtime ouput leave only the line below:
;-o dcblock2.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

sr = 44100
ksmps = 32
nchnls = 2

instr 1 ;add DC to "drumsMlp.wav"

asig soundin "drumsMlp.wav"
asig = asig+5000        ;adds DC of 5000
     outs asig, asig
endin

instr 2 ;dcblock audio

asig soundin "drumsMlp.wav"
asig = asig+5000        ;adds DC
adc  dcblock2 asig      ;remove DC again
     outs adc, adc

endin

</CsInstruments>
<CsScore>

i 1 0 2
i 2 2 2
e

</CsScore>
</CsoundSynthesizer>

See also

Specialized Filters: High pass filters

Credits

By: Victor Lazzarini

New in Csound version 5.09