gstplayer.py

   1 import os, os.path
   2 from mutagen.mp3 import MP3
   3
   4 try:
   5     import pygst
   6     pygst.require('0.10')
   7     import gst
   8 except:
   9     raise ImportError('You need gstreamer version >=0.10 and its python bindings')
  10 try:
  11     import gobject
  12 except:
  13     raise ImportError('You need gobject')
  14
  15 from player import Player, isblank
  16 import settings
  17
  18 class GstPlayer(Player):
  19     """Implements Player with the python gstreamer bindings."""
  20
  21     def __init__(self):
  22         super(GstPlayer, self).__init__()
  23
  24         self.player = gst.element_factory_make('playbin', 'player')
  25         self.audio = None
  26
  27     @property
  28     def isplaying(self):
  29         if self.player and self.player.get_state()[1] is gst.STATE_PLAYING:
  30             return True
  31         else:
  32             return False
  33
  34     @property
  35     def ispaused(self):
  36         if self.player and self.player.get_state()[1] is not gst.STATE_PAUSED:
  37             return False
  38         else:
  39             return True
  40
  41     @property
  42     def position(self):
  43         try:
  44             return self.player.query_position(gst.Format(gst.FORMAT_TIME), None)[0]
  45         except:
  46             return 0
  47
  48     @property
  49     def duration(self):
  50         if self.audio:
  51             # we do everything in nanoseconds like gstreamer does
  52             return self.audio.info.length * 1000000000
  53         else:
  54             return 0
  55
  56     def play(self):
  57         if isblank(self.status.filepath):
  58             return False
  59
  60         if isblank(self.player.get_property('uri')):
  61             self.load()
  62
  63         if not gst.uri_is_valid(self.player.get_property('uri')):
  64             return false
  65
  66         self.seek_if_needed()
  67         if self.player.set_state(gst.STATE_PLAYING) is gst.STATE_CHANGE_FAILURE:
  68             return False
  69         self.timer = self.new_timer()
  70         return True
  71
  72     def pause(self):
  73         if self.player.set_state(gst.STATE_PAUSED) is gst.STATE_CHANGE_FAILURE:
  74             return False
  75         gobject.source_remove(self.timer)
  76         return True
  77
  78     def stop(self, widget=None):
  79         self.player.seek_simple(gst.Format(gst.FORMAT_TIME), gst.SEEK_FLAG_FLUSH, self.status.begin)
  80
  81         if self.player.set_state(gst.STATE_NULL) is gst.STATE_CHANGE_FAILURE:
  82             return False
  83
  84         if self.timer:
  85             gobject.source_remove(self.timer)
  86
  87         return True
  88
  89     def load(self):
  90         self.status.begin = 0
  91         if not self.stop():
  92             return False
  93
  94         if os.path.exists(self.status.filepath):
  95             self.player.set_property('uri', 'file://' + self.status.filepath)
  96             self.player.set_state(gst.STATE_READY)
  97
  98             self.audio = MP3(self.status.filepath)
  99             self.status.end = self.duration
 100             return True
 101
 102         return False
 103
 104     def check_status(self):
 105         if self.timer:
 106             gobject.source_remove(self.timer)
 107
 108         wasplaying = self.isplaying
 109
 110         self.seek_if_needed()
 111
 112         if wasplaying:
 113             self.timer = self.new_timer()
 114
 115     def seek_if_needed(self):
 116         if not self.status.begin <= self.position < self.status.end:
 117             self.player.seek_simple(gst.Format(gst.FORMAT_TIME),
 118                     gst.SEEK_FLAG_FLUSH, long(self.status.begin))
 119
 120     def new_timer(self):
 121         return gobject.timeout_add(int(min(self.status.end - self.position, 1000000000) / 1000000), self.check_status)
 122