[xubuntu-users] 14.04 PulseAudio volume issues

[George F. Nemeyer]

With 14.04 Xubuntu:

Pulse audio control program "pactl" fails to control volume as described
by the manual page which states:

  set-sink-volume SINK VOLUME

  Set the volume of the specified sink (identified by its symbolic name or
  numerical index). VOLUME can be specified as an integer (e.g. 2000,
  16384), a linear factor (e.g. 0.4, 1.100), a percentage (e.g. 10%, 100%)
  or a decibel value (e.g. 0dB, 20dB). If the volume specification start
  with a + or - the volume adjustment will be relative to the current sink
  volume.

- Setting volume with a fixed percentage (50%) seems to work.
- Increasing volume using a increment percentage (+20%)seems to work.

      However with both these, there's apparently NO sanity checks, so you
      can set volume to 1000% or +1000%.  (I don't even *want* to know
      what it will actually do with such settings!)  The same values are
      reflected in the graphical volume slider Volume Control utility.

- Trying to set the volume with a *decrement* percentage (-20%) FAILS with
no change to the setting.  When attempting this from a terminal command
line, you get:

       pactl:  invalid option -- '2'

       or whatever is the first digit after the - sign.

This makes programming keyboard shortcuts to enable volume up/down buttons
to work useless, as you can't turn the volume DOWN by an incremental
amount.