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Groups > comp.lang.python > #18201

Re: Generating sin/square waves sound

Date 2011-12-30 05:05 -0500
From Dave Angel <d@davea.name>
Subject Re: Generating sin/square waves sound
References <jdjohn$ttr$1@speranza.aioe.org>
Newsgroups comp.lang.python
Message-ID <mailman.4239.1325239510.27778.python-list@python.org> (permalink)

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On 12/30/2011 02:17 AM, Paulo da Silva wrote:
> Hi,
> Sorry if this is a FAQ, but I have googled and didn't find any
> satisfatory answer.
>
> Is there a simple way, preferably multiplataform (or linux), of
> generating sinusoidal/square waves sound in python?
>
> Thanks for any answers/suggestions.
If you're willing to be Linux-only, then I believe you can do it without 
any extra libraries.

You build up a string (8 bit char, on Python 2.x)  of samples, and write 
it to  "/dev/audio".  When i experimented, I was only interested in a 
few seconds, so a single write was all I needed.

Note that the samples are 8 bits, and they are offset by 128.  So a zero 
signal would be a string of 128 values.  A very quiet square wave might 
be a bunch of 126, followed by a bunch of 130.  and so on.  And the 
loudest might be a bunch of 2's followed by a bunch of 253's.

You'll have to experiment with data rate;   The data is sent out at a 
constant rate from your string, but I don't know what that rate is.


-- 

DaveA

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Thread

Generating sin/square waves sound Paulo da Silva <p_s_d_a_s_i_l_v_a@netcabo.pt> - 2011-12-30 07:17 +0000
  Re: Generating sin/square waves sound 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-30 01:51 -0800
  Re: Generating sin/square waves sound Dave Angel <d@davea.name> - 2011-12-30 05:05 -0500
    Re: Generating sin/square waves sound Paulo da Silva <p_s_d_a_s_i_l_v_a@netcabo.pt> - 2012-01-02 07:24 +0000
      Re: Generating sin/square waves sound Dave Angel <d@davea.name> - 2012-01-02 12:12 -0500
  Re: Generating sin/square waves sound mblume <foobar@invalid.invalid> - 2011-12-30 11:23 +0000
    Re: Generating sin/square waves sound Paulo da Silva <p_s_d_a_s_i_l_v_a@netcabo.pt> - 2012-01-02 07:31 +0000
      Re: Generating sin/square waves sound Peter Billam <peter@www.pjb.com.au> - 2012-01-02 10:05 +0000
  Re: Generating sin/square waves sound K Richard Pixley <rich@noir.com> - 2011-12-30 17:19 -0800
    Re: Generating sin/square waves sound Paulo da Silva <p_s_d_a_s_i_l_v_a@netcabo.pt> - 2012-01-02 07:34 +0000
  Re: Generating sin/square waves sound Paulo da Silva <p_s_d_a_s_i_l_v_a@netcabo.pt> - 2012-01-02 18:09 +0000

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