src/gpodder/gstreamer.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # gPodder - A media aggregator and podcast client
   4 # Copyright (c) 2005-2010 Thomas Perl and the gPodder Team
   5 #
   6 # gPodder is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # gPodder is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 #
  19
  20 try:
  21     import gobject
  22     import pygst
  23     pygst.require('0.10')
  24     import gst
  25     from gst.extend.discoverer import Discoverer
  26     have_gst = True
  27 except:
  28     have_gst = False
  29
  30 class GstFile:
  31     def __init__(self):
  32         self.mainloop = gobject.MainLoop()
  33         self.result = None
  34
  35     def run(self, filename):
  36         gobject.idle_add(self.on_idle, filename)
  37         self.mainloop.run()
  38         return self.result / gst.MSECOND
  39
  40     def on_idle(self, filename):
  41         d = Discoverer(filename)
  42         d.connect('discovered', self.on_data)
  43         d.discover()
  44         return False
  45
  46     def on_data(self, discoverer, ismedia):
  47         if discoverer.is_video:
  48             self.result = discoverer.videolength
  49         elif discoverer.is_audio:
  50             self.result = discoverer.audiolength
  51         gobject.idle_add(self.mainloop.quit)
  52
  53 def get_track_length(filename):
  54     """
  55     Returns track length in microseconds.
  56
  57     Prefers video streams to audio streams. If no supported streams were found,
  58     returns None.
  59     """
  60     if not have_gst:
  61         return None
  62     return GstFile().run(filename)
  63
  64 __all__ = ['get_track_length']
  65
  66 # vim: set ts=4 sts=4 sw=4 et: