GStreamer 上的视频过渡？

Question

我正在尝试创建一个相当不寻常的程序，该程序需要视频从一个剪辑顺利播放到下一个剪辑，而不闪烁。此时，在流的末尾，我更改了下一个剪辑的路径并将其设置为再次播放。这个效果很好，除了中间有一个小眨眼，这不是最佳的。

我想我可以通过在视频剪辑之间创建过渡来摆脱这个问题。但是，由于缺少 Python 的 GStreamer 教程...我该怎么做？

我正在使用 Python 2.7、PyGTK 2.24 和 GStreamer。

这是我当前的代码：

import pygtk
pygtk.require('2.0')
import gtk, pango
import pygst
pygst.require('0.10')
import gst
import Trailcrest
import os, sys

class Video:

    def __init__(self):

        def on_message(bus, message): 
            if message.type == gst.MESSAGE_EOS: 
                # End of Stream 
                player.set_state(gst.STATE_NULL)
                player.set_property("uri", "file://" + os.getcwd() + "/VID/BGA-AMB-HABT-001.ogv") 
                player.set_state(gst.STATE_PLAYING) 
            elif message.type == gst.MESSAGE_ERROR: 
                player.set_state(gst.STATE_NULL) 
                (err, debug) = message.parse_error() 
                print "Error: %s" % err, debug

        def on_sync_message(bus, message):
            if message.structure is None:
                return False
            if message.structure.get_name() == "prepare-xwindow-id":
                gtk.gdk.threads_enter()
                gtk.gdk.display_get_default().sync()
                win_id = videowidget.window.xid
                imagesink = message.src
                imagesink.set_property("force-aspect-ratio", True)
                imagesink.set_xwindow_id(win_id)
                gtk.gdk.threads_leave()

        win = gtk.Window()
        win.set_resizable(False)
        win.set_has_frame(False)
        win.set_position(gtk.WIN_POS_CENTER)

        fixed = gtk.Fixed()
        win.add(fixed)
        fixed.show()

        pixbuf = gtk.gdk.pixbuf_new_from_file_at_size("IMG/IMG-AMB-HABT-001.png", 640, 480)
        pixbuf = pixbuf.scale_simple(640, 480, gtk.gdk.INTERP_BILINEAR)
        pixmap, mask = pixbuf.render_pixmap_and_mask()
        img = gtk.Image()
        img.set_from_pixmap(pixmap, mask)
        fixed.put(img, 0, 0)
        img.show()

        videowidget = gtk.DrawingArea()
        fixed.put(videowidget, 0, 0)
        videowidget.set_size_request(640, 480)
        videowidget.show()

        # Setup GStreamer 
        player = gst.element_factory_make("playbin", "MultimediaPlayer")
        bus = player.get_bus() 
        bus.add_signal_watch() 
        bus.enable_sync_message_emission() 
        #used to get messages that GStreamer emits 
        bus.connect("message", on_message) 
        #used for connecting video to your application 
        bus.connect("sync-message::element", on_sync_message)
        player.set_property("uri", "file://" + os.getcwd() + "/VID/BGA-AMB-HABT-001.ogv") 
        player.set_state(gst.STATE_PLAYING)

        win.show()

def main():
    gtk.gdk.threads_init()
    gtk.main()
    return 0

if __name__ == "__main__":
    Video()
    main()