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.set_seek(0)
  47
  48     def on_error(self, bus, msg):
  49         (err, debug) = msg.parse_error()
  50         print "Error: %s" % err, debug
  51         self.quit()
  52
  53     def on_state_changed(self, bus, msg):
  54         if msg.src != self._player:
  55             return
  56
  57         print 'on_state_changed'
  58         old_state, new_state, pending = msg.parse_state_changed()
  59         print "%s -> %s" % (old_state, new_state)
  60         if old_state == Gst.State.READY and new_state == Gst.State.PAUSED:
  61             self.set_rate(self._rate)
  62
  63     def set_rate(self, rate):
  64         self._rate = rate
  65         self.set_seek(0, True)
  66
  67     def set_seek(self, position, flush=False):
  68         flags = Gst.SeekFlags.SEGMENT | Gst.SeekFlags.SKIP | Gst.SeekFlags.ACCURATE
  69
  70         if flush:
  71             flags |= Gst.SeekFlags.FLUSH
  72
  73         if self._rate >= 0:
  74             seek_event = Gst.Event.new_seek(self._rate,
  75                                             Gst.Format.TIME,
  76                                             flags,
  77                                             Gst.SeekType.SET, position,
  78                                             Gst.SeekType.NONE, 0)
  79         else:
  80             seek_event = Gst.Event.new_seek(self._rate,
  81                                             Gst.Format.TIME,
  82                                             flags,
  83                                             Gst.SeekType.NONE, 0,
  84                                             Gst.SeekType.END, position)
  85
  86         if seek_event:
  87             self._player.send_event(seek_event)
  88             Gst.info("rate set to %s" % self._rate)
  89         else:
  90             Gst.warining("change rate failed")
  91
  92
  93 def main(args):
  94     def usage():
  95         sys.stdout.write("usage: %s <filename> <speedrate>\n" % args[0])
  96
  97     if len(args) != 3:
  98         usage()
  99         sys.exit(1)
 100
 101     uri = Gst.filename_to_uri(args[1])
 102     rate = float(args[2])
 103
 104     player = Player(uri, rate)
 105     player.run()
 106
 107 if __name__ == '__main__':
 108     sys.exit(main(sys.argv))