gst-trick-mode-looping-2.py

   1 #!/usr/bin/env python
   2
   3 # Get a test sample with:
   4 # youtube-dl -t http://www.youtube.com/watch?v=yWa-YXiSk2Y
   5
   6 import sys
   7
   8 import gobject
   9 gobject.threads_init()
  10
  11 import gst
  12
  13
  14 class Player:
  15     def __init__(self, filename, rate):
  16         self._filename = filename
  17         self._rate = rate
  18
  19         self._player = gst.element_factory_make("playbin2", "player")
  20         self._player.set_property("uri", filename)
  21         self._player.connect("about-to-finish", self.on_about_to_finish)
  22
  23         bus = self._player.get_bus()
  24         bus.add_signal_watch()
  25         bus.connect('message::state-changed', self.on_state_changed)
  26
  27     def run(self):
  28         self._player.set_state(gst.STATE_PLAYING)
  29         loop = gobject.MainLoop()
  30         loop.run()
  31
  32     def on_about_to_finish(self, player):
  33         sys.stderr.write(".")
  34         player.set_property("uri", self._filename)
  35
  36         # XXX Ater the first iteration of the loop the playback rate is
  37         # reset to normal. Do I need to re-set the rate here?
  38
  39         # If I uncomment the following line, the player hangs:
  40         #self.set_rate(self._date)
  41
  42         # And it hangs also if I set the seek_event manually using position=0:
  43         #seek_event = gst.event_new_seek(self._rate,
  44         #        gst.FORMAT_TIME,
  45         #        gst.SEEK_FLAG_FLUSH | gst.SEEK_FLAG_ACCURATE,
  46         #        gst.SEEK_TYPE_SET, 0,
  47         #        gst.SEEK_TYPE_NONE, 0)
  48         #self._player.send_event(seek_event)
  49
  50     def on_state_changed(self, bus, msg):
  51         if msg.src != self._player:
  52             return
  53
  54         print 'on_state_changed'
  55         old_state, new_state, pending = msg.parse_state_changed()
  56         print "%s -> %s" % (old_state, new_state)
  57         if old_state == gst.STATE_READY and new_state == gst.STATE_PAUSED:
  58             self.set_rate(self._rate)
  59
  60     def set_rate(self, rate):
  61         self._rate = rate
  62         try:
  63             position, format = self._player.query_position(gst.FORMAT_TIME)
  64         except:
  65             position = 0
  66
  67         # Create the seek event
  68         if rate > 0:
  69             seek_event = gst.event_new_seek(rate,
  70                     gst.FORMAT_TIME,
  71                     gst.SEEK_FLAG_FLUSH | gst.SEEK_FLAG_ACCURATE,
  72                     gst.SEEK_TYPE_SET, position,
  73                     gst.SEEK_TYPE_NONE, 0)
  74         else:
  75             seek_event = gst.event_new_seek(rate,
  76                     gst.FORMAT_TIME,
  77                     gst.SEEK_FLAG_FLUSH | gst.SEEK_FLAG_ACCURATE,
  78                     gst.SEEK_TYPE_SET, 0,
  79                     gst.SEEK_TYPE_SET, position)
  80
  81         if seek_event:
  82             self._player.send_event(seek_event)
  83             gst.info("rate set to %s" % rate)
  84         else:
  85             gst.warining("change rate failed")
  86
  87
  88 def main(args):
  89     def usage():
  90         sys.stdout.write("usage: %s <URI-OF-MEDIA-FILE>\n" % args[0])
  91
  92     if len(args) != 2:
  93         usage()
  94         sys.exit(1)
  95
  96     if not gst.uri_is_valid(args[1]):
  97         sys.stderr.write("Error: Invalid URI: %s\n" % args[1])
  98         sys.exit(1)
  99
 100     player = Player(args[1], 3.0)
 101     player.run()
 102
 103 if __name__ == '__main__':
 104     sys.exit(main(sys.argv))