python/gst-trick-mode-looping-3.py

   1 #!/usr/bin/env python
   2 #
   3 # A simple "trick-mode" looping player.
   4 # Version 3, based on segment seeking.
   5 #
   6 # TODO: the trickmodes work way better but the looping functionality
   7 # needs to be fixed.
   8 #
   9 # Get a test sample with:
  10 # youtube-dl -t http://www.youtube.com/watch?v=yWa-YXiSk2Y
  11
  12 import sys
  13
  14 import gi
  15 gi.require_version('Gst', '1.0')
  16 from gi.repository import Gst
  17 Gst.init(None)
  18
  19 from gi.repository import GObject
  20 GObject.threads_init()
  21
  22
  23 class Player:
  24     def __init__(self, uri, rate):
  25         self._rate = rate
  26
  27         self._player = Gst.ElementFactory.make("playbin", "player")
  28         self._player.set_property("uri", uri)
  29
  30         bus = self._player.get_bus()
  31         bus.add_signal_watch()
  32         bus.connect('message::error', self.on_error)
  33         bus.connect('message::segment-done', self.on_segment_done)
  34         bus.connect('message::state-changed', self.on_state_changed)
  35
  36     def run(self):
  37         self._player.set_state(Gst.State.PLAYING)
  38         self.loop = GObject.MainLoop()
  39         self.loop.run()
  40
  41     def quit(self):
  42         self._player.set_state(Gst.State.NULL)
  43         self.loop.quit()
  44
  45     def on_segment_done(self, bus, msg):
  46         self._player.seek(self._rate, Gst.Format.TIME,
  47                           Gst.SeekFlags.SEGMENT | Gst.SeekFlags.SKIP | Gst.SeekFlags.ACCURATE,
  48                           Gst.SeekType.SET, 0,
  49                           Gst.SeekType.END, 0)
  50
  51     def on_error(self, bus, msg):
  52         (err, debug) = msg.parse_error()
  53         print "Error: %s" % err, debug
  54         self.quit()
  55
  56     def on_state_changed(self, bus, msg):
  57         if msg.src != self._player:
  58             return
  59
  60         print 'on_state_changed'
  61         old_state, new_state, pending = msg.parse_state_changed()
  62         print "%s -> %s" % (old_state, new_state)
  63         if old_state == Gst.State.READY and new_state == Gst.State.PAUSED:
  64             self.set_rate(self._rate)
  65
  66     def set_rate(self, rate):
  67         self._rate = rate
  68
  69         if rate == 0:
  70             self._player.set_state(Gst.State.PAUSED)
  71         else:
  72             self._player.set_state(Gst.State.PLAYING)
  73             self._player.seek(rate,
  74                               Gst.Format.TIME,
  75                               Gst.SeekFlags.SEGMENT | Gst.SeekFlags.SKIP | Gst.SeekFlags.FLUSH | Gst.SeekFlags.ACCURATE,
  76                               Gst.SeekType.SET, 0,
  77                               Gst.SeekType.END, 0)
  78
  79
  80 def main(args):
  81     def usage():
  82         sys.stdout.write("usage: %s <filename> <speedrate>\n" % args[0])
  83
  84     if len(args) != 3:
  85         usage()
  86         sys.exit(1)
  87
  88     uri = Gst.filename_to_uri(args[1])
  89     rate = float(args[2])
  90
  91     player = Player(uri, rate)
  92     player.run()
  93
  94 if __name__ == '__main__':
  95     sys.exit(main(sys.argv))