import gobject
gobject.threads_init()
import gst
import pygtk
pygtk.require("2.0")
import gtk
import sys
def new_pad_cb(element, pad, target):
    dest_pad = target.get_compatible_pad(pad)
    if dest_pad:
        pad.link(dest_pad)

# set up media pipeline
src = gst.element_factory_make("filesrc")
src.set_property("location", sys.argv[1])
dec = gst.element_factory_make("decodebin2")
aconv = gst.element_factory_make("audioconvert")
sink = gst.element_factory_make("alsasink")
volume = gst.element_factory_make("volume")
bin = gst.Bin()

bin.add(src, dec, aconv, sink, volume)
src.link(dec)
dec.connect("pad-added", new_pad_cb, volume)
volume.link(aconv)
aconv.link(sink)

def buttonCb(button):
    if button == playBtn:
        bin.set_state(gst.STATE_PLAYING)
    elif button == stopBtn:
        bin.set_state(gst.STATE_READY)

def volumeCb(scale):
    volume.set_property("volume", scale.get_value())

# UI code
window = gtk.Window()
window.set_size_request(320, 240)
playBtn = gtk.Button("Play")
playBtn.connect("clicked", buttonCb)
stopBtn = gtk.Button("Stop")
stopBtn.connect("clicked", buttonCb)
volumeScale = gtk.HScale()
volumeScale.set_range(0, 10)
volumeScale.connect("value-changed", volumeCb)
volumeScale.set_value(1)
volumeScale.set_update_policy(gtk.UPDATE_CONTINUOUS)
box = gtk.VBox()
for widget in [playBtn, stopBtn, volumeScale]:
    box.pack_start(widget)
window.add(box)
window.show_all()
window.connect("destroy", gtk.main_quit)
gtk.main()