Question

我想使用gi.repository中的Gst而不是常规gst。 https://wiki.ubuntu.com/Novacut/GStreamer1.0这里是指南。这是代码：

#!/usr/bin/env python
from gi.repository import GObject
from gi.repository import GLib
from gi.repository import Gtk
from gi.repository import Gst
Gst.init(None)
class PlaybackInterface:

    def __init__(self):
    self.playing = False

    # A free example sound track
    self.uri = "http://cdn02.cdn.gorillavsbear.net/wp-content/uploads/2012/10/GORILLA-VS-BEAR-OCTOBER-2012.mp3"

    # GTK window and widgets
    self.window = Gtk.Window()
    self.window.set_size_request(300,50)

    vbox = Gtk.Box(Gtk.Orientation.HORIZONTAL, 0)
    vbox.set_margin_top(3)
    vbox.set_margin_bottom(3)
    self.window.add(vbox)

    self.playButtonImage = Gtk.Image()
    self.playButtonImage.set_from_stock("gtk-media-play", Gtk.IconSize.BUTTON)
    self.playButton = Gtk.Button.new()
    self.playButton.add(self.playButtonImage)
    self.playButton.connect("clicked", self.playToggled)
    Gtk.Box.pack_start(vbox, self.playButton, False, False, 0)

    self.slider = Gtk.HScale()
    self.slider.set_margin_left(6)
    self.slider.set_margin_right(6)
    self.slider.set_draw_value(False)
    self.slider.set_range(0, 100)
    self.slider.set_increments(1, 10)

    Gtk.Box.pack_start(vbox, self.slider, True, True, 0)

    self.label = Gtk.Label(label='0:00')
    self.label.set_margin_left(6)
    self.label.set_margin_right(6)
    Gtk.Box.pack_start(vbox, self.label, False, False, 0)

    self.window.show_all()

        # GStreamer Setup
        Gst.init_check(None)
        self.IS_GST010 = Gst.version()[0] == 0
    self.player = Gst.ElementFactory.make("playbin2", "player")
    fakesink = Gst.ElementFactory.make("fakesink", "fakesink")
    self.player.set_property("video-sink", fakesink)
    bus = self.player.get_bus()
    #bus.add_signal_watch_full()
    bus.connect("message", self.on_message)
    self.player.connect("about-to-finish",  self.on_finished)

    def on_message(self, bus, message):
    t = message.type
    if t == Gst.Message.EOS:
        self.player.set_state(Gst.State.NULL)
        self.playing = False
    elif t == Gst.Message.ERROR:
        self.player.set_state(Gst.State.NULL)
        err, debug = message.parse_error()
        print "Error: %s" % err, debug
        self.playing = False

    self.updateButtons()

    def on_finished(self, player):
    self.playing = False
        self.slider.set_value(0)
    self.label.set_text("0:00")
        self.updateButtons()

    def play(self):
    self.player.set_property("uri", self.uri)
    self.player.set_state(Gst.State.PLAYING)
    GObject.timeout_add(1000, self.updateSlider)

    def stop(self):
    self.player.set_state(Gst.State.NULL)

    def playToggled(self, w):
        self.slider.set_value(0)
    self.label.set_text("0:00")

    if(self.playing == False):
        self.play()
    else:
        self.stop()

    self.playing=not(self.playing)
    self.updateButtons()

    def updateSlider(self):
    if(self.playing == False):
       return False # cancel timeout

    try:
       if self.IS_GST010:
          nanosecs = self.player.query_position(Gst.Format.TIME)[2]
          duration_nanosecs = self.player.query_duration(Gst.Format.TIME)[2]
       else:
          nanosecs = self.player.query_position(Gst.Format.TIME)[1]
          duration_nanosecs = self.player.query_duration(Gst.Format.TIME)[1]

       # block seek handler so we don't seek when we set_value()
       # self.slider.handler_block_by_func(self.on_slider_change)

           duration = float(duration_nanosecs) / Gst.SECOND
       position = float(nanosecs) / Gst.SECOND
       self.slider.set_range(0, duration)
       self.slider.set_value(position)
           self.label.set_text ("%d" % (position / 60) + ":%02d" % (position % 60))

       #self.slider.handler_unblock_by_func(self.on_slider_change)

    except Exception as e:
        # pipeline must not be ready and does not know position
        print e
        pass

    return True

    def updateButtons(self):
        if(self.playing == False):
           self.playButtonImage.set_from_stock("gtk-media-play", Gtk.IconSize.BUTTON)
        else:
           self.playButtonImage.set_from_stock("gtk-media-stop", Gtk.IconSize.BUTTON)

if __name__ == "__main__":
    PlaybackInterface()
    Gtk.main()

但我有：

Traceback (most recent call last):
  File "./xy", line 134, in <module>
    PlaybackInterface()
  File "./xy", line 52, in __init__
    self.player.set_property("video-sink", fakesink)
AttributeError: 'NoneType' object has no attribute 'set_property'

错误。如何使用Gst.ElementFactory.make？它返回None？

Answer 1

使用playbin而不是playbin2。

self.player = Gst.ElementFactory.make("playbin", "player")

ElementFactory.make返回none，因为Gst-1.0中没有playbin2元素。 Playbin2在Gst-0.1

中

Python gi.repository Gst.ElementFactory.make返回None？

1 个答案: