oss_control.rb

#!/usr/bin/env ruby

require 'fileutils'

VOLSTORE = File.expand_path('~/.volume')
CHANNEL = 'vmix0-outvol'
MAX_VOLUME = 25

def osd_percentage(perc)
  fork {
    `osd_cat -b percentage -p bottom -c "#285577" -d 1 -A right -o 20 -P #{perc}`
  }
end

def ossmix(*args)
  `ossmix #{CHANNEL} #{args.map{|e|e.to_s}.join(' ')}`
end

def get_cur_volume
    `ossmix #{CHANNEL}`.split(/ /)[9]
end

def toggle
  if File.exists?(VOLSTORE)
    ossmix File.read(VOLSTORE)
    FileUtils.rm VOLSTORE
  else
    cur_volume = get_cur_volume
    ossmix 0
    File.open(VOLSTORE, 'w') { |f| f << cur_volume }
  end
end

def raise_vol
  ossmix '--', '+1'
end

def lower_vol
  ossmix '--', '-1'
end

def show_actual_volume
  vol = ((get_cur_volume.to_f / MAX_VOLUME) * 100).to_i
  osd_percentage vol
end

if ARGV.size != 1
  STDERR.puts <<-EOF
usage: #{$1} [raise|lower|toggle]
  EOF
  exit 1
end

case ARGV.first
when 'raise'
  raise_vol
when 'lower'
  lower_vol
when 'toggle'
  toggle
else
  STDERR.puts 'unknown'
end 
show_actual_volume