How do I play a sound in Octave?

Question

Octave appears to assume that a specific sound playing utility will be available on a system but doesn't seem to provide the ability to specify an alternate. In the error below, Octave is looking for ofsndplay, which is not a utility available on all systems.

octave:38> sound(beamformed_20)

sh: ofsndplay: command not found

Is there an Octave configuration setting or code fragment that I can use to specify an system-appropriate utility?

Answer 1

On Octave 4.2.1. You can play a wav file as follows

Save the following code in a file playWav.m

function playWav(inputFilePath)
  [y, fs] = audioread(inputFilePath);
  player  = audioplayer(y, fs);
  playblocking(player)
end

Then you can call the function as playWav('/path/to/wavfile'); from Octave commandline.

Tested on Windows 7.

Answer 2

On one of my Linux machines, I created the following ofsndplay script to work around the hard-wired dependency:

$ cat /usr/bin/ofsndplay

#!/bin/sh
## Coping with stupid dependency on ofsndplay in octave
play -t au -

This particular script uses the SoX play utility.

Admittedly, the comment is unnecessary for the functionality but it certainly made me feel better....

Answer 3

I've overridden the playaudio function from octave with the following function. This will work only after installing sox.

sudo apt-get install sox

(in ubuntu)

function [ ] = playaudio (x, sampling_rate)

    if nargin == 1
        sampling_rate = 8000
    end
    file = tmpnam ();
    file= [file, '.wav'];
    wavwrite(x, sampling_rate, file);
    ['play ' file ]
    system(['play ' file ]);
    system(['rm ' file]);
end

A similar approach will allow you to record too:

% Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2003, 2004, 2005,
%               2006, 2007 John W. Eaton
%
% This file is part of Octave.
%
% Octave is free software; you can redistribute it and/or modify it
% under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 3 of the License, or (at
% your option) any later version.
%
% Octave is distributed in the hope that it will be useful, but
% WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
% General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with Octave; see the file COPYING.  If not, see
% <http://www.gnu.org/licenses/>.

% -*- texinfo -*-
% @deftypefn {Function File} {} record (@var{sec}, @var{sampling_rate})
% Records @var{sec} seconds of audio input into the vector @var{x}.  The
% default value for @var{sampling_rate} is 8000 samples per second, or
% 8kHz.  The program waits until the user types @key{RET} and then
% immediately starts to record.
% @seealso{lin2mu, mu2lin, loadaudio, saveaudio, playaudio, setaudio}
% @end deftypefn

% Author: AW <[email protected]>
% Created: 19 September 1994
% Adapted-By: jwe
% And adapted again 11/25/2010 by Rob Frohne    
function X = record (sec, sampling_rate)


  if (nargin == 1)
    sampling_rate = 8000;
  elseif (nargin != 2)
    print_usage ();
  endif

  file = tmpnam ();
  file= [file,".wav"];

  input ("Please hit ENTER and speak afterwards!\n", 1);

  cmd = sprintf ("rec -c1 -r%d %s trim 0 %d",
                   sampling_rate, file, sec)

  system (cmd);

  X = wavread(file);

end