This program will generate a waveform at audio ranges (0-20,000Hz). You can 
change the frequency, volume/amplitude, and waveform type.

This program requires:
    - Python2       [http://www.python.org/download]
    - Gstreamer     [http://www.gstreamer.net/download]
    - gst-python    [http://www.gstreamer.net/modules/gst-python.html]
    - urwid         [http://excess.org/urwid]

Example usage:

signalgen -f 200 -v 0.5 -w triangle -V

Help Message:

Usage: signalgen [options]

Values for wave must be one of: sine, square, saw, triangle, silence, white-
noise, pink-noise, sine-table, ticks, gaussian-noise.  You can adjust the
waveform  properties at runtime by using the following keys; up/down=volume,
left/right=frequency, page up/page down=waveform.

Options:
  -h, --help            show this help message and exit
  -f FREQ, --freq=FREQ  frequency of signal from 0-20000, default 440
  -v VOL, --volume=VOL  volume of signal from 0-1, default 0.8
  -w WAVE, --wave=WAVE  oscillator waveform name, default 'sine'
  -c, --stdout          outputs waveforms to stdout, default off
  -V, --visualize       enable an X oscilloscope window, default off
  -a, --audio           enable audio output, default on
  -q, --quiet           don't print to stdout or stderr, default off

Installing:

    Run 'python setup.py install' as root.
    
Bugs/Todo:

    When using the --visualize option, closing the window causes the audio
    to stop playing but the program does not exit automatically.  Either the
    program should exit or the audio should continue to play until the 
    program is exited normally.