Changevol - volume management (good for binding multimedia keys)

Question

I wrote this script to work with my laptop's multimedia keys. It requires python, pygtk, and alsa-utils. It is a non-interactive program that modifies the volume and then pops up a little gui notifier similar to programs like keytouch (but much simpler and less bloated). It was designed to work by binding multimedia keys (using programs like xbindkeys or any WM's/DE's keybinding apps) to the script and that is probably the only real convenient use.
Here is what it looks like (pops up in the middle of the desktop on top of everything else). Don't worry about the color of the bar and such, it is programmed with gtk2, so it will inherit whatever your gtk theme looks like:
Here is the script. To use: just dump into a text file called "changevol", chmod +x it, and put it in the PATH somewhere:
#!/usr/bin/env python
import pygtk
import gtk
import gobject
import commands
import sys
import os
import re
import getopt
def err(msg):
print msg
sys.exit(1)
def usage():
print '''
Usage: changevol [options] [argument]
Options:
-i, --increase increase volume by `argument'
-d, --decrease decrease volume by `argument'
-c, --control specify the mixer control by `argument' (default Master)
use only to modify a mixer other than Master
-t, --toggle toggle mute on and off
-s, --status display current volume status without modifying it
-q, --quiet don't display the gtk progressbar, just change the volume
-b, --backlight adjust the backlight using xbacklight
-h, --help display this help message
Note:
Volume increases and decreases won't be exact due to amixer oddities.
sys.exit(0)
class GetVolInfo():
def __init__(self, command):
self.amixeroutput = commands.getoutput(command)
if re.compile("off]$", re.M).search(self.amixeroutput, 1):
self.realvol = "0"
self.endlabel = "Mute"
else:
self.tempvolarray1 = self.amixeroutput.split("[")
self.tempvolarray2 = self.tempvolarray1[1].split("%")
self.realvol = self.tempvolarray2[0]
self.endlabel = self.realvol + " %"
self.percent = float(self.realvol)/100
self.label = "Volume " + self.endlabel
class ProgressBar:
def timeout_callback(self):
gtk.main_quit()
return False
def __init__(self, fraction, label):
self.window = gtk.Window(gtk.WINDOW_POPUP)
self.window.set_border_width(0)
self.window.set_default_size(180, -1)
self.window.set_position(gtk.WIN_POS_CENTER)
timer = gobject.timeout_add(1000, self.timeout_callback)
self.bar = gtk.ProgressBar()
self.bar.set_fraction(fraction)
self.bar.set_orientation(gtk.PROGRESS_LEFT_TO_RIGHT)
self.bar.set_text(label)
self.bar.show()
self.window.add(self.bar)
self.window.show()
#Run through parameters, set variables and such
CONTROL = "Master"
AMIXEROPTION = "unset"
QUIET = "NO"
BACKLIGHT = "NO"
if (len(sys.argv) < 2):
usage()
try:
opts, args = getopt.getopt(sys.argv[1:], "bqhtsc:i:d:", ["backlight" "quiet", "help", "toggle", "status", "control=", "increase=", "decrease="])
except getopt.GetoptError:
err("Incorrect usage, see changevol --help.")
if (len(opts) == 0):
err("Incorrect usage, see --help.")
for opt, arg in opts:
if opt in ("-h", "--help"):
usage()
elif opt in ("-q", "--quiet"):
QUIET = "YES"
elif opt in ("-b", "--backlight"):
BACKLIGHT = "YES"
elif opt in ("-t", "--toggle"):
AMIXEROPTION = "toggle"
elif opt in ("-s", "--status"):
INCREMENT = "0"
AMIXEROPTION = INCREMENT + "%+"
elif opt in ("-c", "--control"):
CONTROL = arg
elif opt in ("-i", "--increase"):
INCREMENT = arg
AMIXEROPTION = INCREMENT + "%+"
elif opt in ("-d", "--decrease"):
INCREMENT = arg
AMIXEROPTION = INCREMENT + "%-"
else:
err("Incorrect usage, see --help")
if (AMIXEROPTION == "unset"):
err("No volume changing action has been dictated. See changevol --help.")
command = "amixer set " + CONTROL + " " + AMIXEROPTION
#Execution
volume = GetVolInfo(command)
if (QUIET == "NO"):
ProgressBar(volume.percent, volume.label)
gtk.main()
if (BACKLIGHT == "YES"):
os.execv('/usr/bin/xbacklight', ['placeholder', '-set', volume.realvol])
Here is the usage synopsis (it can be accessed with changevol --help):
Usage: changevol [options] [argument]
Options:
  -i, --increase  increase volume by `argument'
  -d, --decrease  decrease volume by `argument'
  -c, --control   specify the mixer control by `argument' (default Master)
                  use only to modify a mixer other than Master
  -t, --toggle    toggle mute on and off
  -s, --status    display current volume status without modifying it
  -q, --quiet     don't display the gtk progressbar, just change the volume
  -b, --backlight adjust the backlight using xbacklight
  -h, --help      display this help message
Note:
  Volume increases and decreases won't be exact due to amixer oddities.
Edit: Changed mute handling a bit.
Edit2: Added a -c, --control option for an amixer interface other than Master
Edit3: Added a -s, --status option to just display the current volume status without modifying it
Edit4: Added a -q, --quiet option to not show the progress bar and just change the volume
Edit5: Added a -b, --backlight option to adjust the backlight along with the volume change (someone asked for it, so why the hell not right?)
Last edited by bruenig (2008-02-03 06:43:07)

Answer 1

ralvez wrote:I gave it a spin but every time I get the same answer: "No volume changing action has been dictated."
Can you provide an example of issuing the command using xbindkeys? or even what I should be issuing on the command line? I must be doing something wrong ... and I do not feel like studying the code to figure it out since you can give me the answer just as fast
The usage synopsis is in the first post or available by just doing "changevol" or changevol -h|--help.
But to increase the volume by 5:
changevol -i 5
To decrease the volume by 5:
changevol -d 5
To toggle mute on and off:
changevol -t
If you need to specify a mixer other than "Master" which is the default mixer, you use the -c flag, so say you needed to use the mixer "Front" to increase by 5:
changevol -c Front -i 5
I see there is a problem in the code where it says No volume changing action has been dictated when I want it to say Incorrect usage, see changevol --help. I will try to fix that. Still learning python.
Edit: I have changed it to see if getopts returns no options and then if so print back the Incorrect usage error message. That should do a lot to direct people to the right, direction. I have also, changed the No volume changing action one, to also direct to --help.
Last edited by bruenig (2007-12-31 03:27:37)