在Raspbian上定义gstreamer视频窗口的问题

Question

在python中使用Gstreamer'playbin'，'set_window_handle'代码告诉Gstreamer用于呈现视频的窗口ID：

这适用于标准Linux Mate以及运行Ubuntu-Mate的Raspberry Pi 3。但是，在同一个Raspberry上运行但运行最新的Raspbian操作系统，Gstreamer完全忽略了在特定窗口中运行的指令，而是创建了自己的窗口，在屏幕中间闪烁。 如果新窗口能够被操纵，移动和/或调整大小但它不能，则这不是问题。它无法移动，无法关闭，鼠标指针在其后面消失 有没有人知道这是Raspbian，X windows或Gstreamer中的错误还是我没有发现为了在Raspbian OS上工作必须实施的一些更改？
这是一个最小的工作示例，它说明了上述行为。

#!/usr/bin/env python
import os,time
import wx
import gi
gi.require_version('Gst', '1.0')
gi.require_version('GstVideo', '1.0')
from gi.repository import Gst
from gi.repository import GstVideo

class Player(wx.App):

    def OnInit(self):
        window = wx.Frame(None)
        window.SetTitle("Gstreamer Player Test")
        window.SetSize((-1,-1))
        window.Bind(wx.EVT_CLOSE,self.close)
        vbox = wx.BoxSizer(wx.VERTICAL)
        hbox = wx.BoxSizer(wx.HORIZONTAL)
        self.fileid = wx.TextCtrl(window,style=wx.TE_PROCESS_ENTER)
        self.fileid.SetToolTipString("Enter full path to media file")
        hbox.Add(self.fileid, 1)
        self.start = wx.Button(window,label="Start")
        hbox.Add(self.start, 0)
        self.start.Bind(wx.EVT_BUTTON, self.control)
        self.fileid.Bind(wx.EVT_TEXT_ENTER, self.control)
        vbox.Add(hbox, 0, wx.EXPAND, 0)
        self.video_window = wx.Panel(window)
        vbox.Add(self.video_window,1,wx.EXPAND,5)
        window.SetSizer(vbox)
        window.Layout()
        window.Show()
        self.SetTopWindow(window)
        Gst.init(None) #initialise gstreamer
        self.player = Gst.ElementFactory.make("playbin", "player")
        bus = self.player.get_bus()
        bus.add_signal_watch() #hook up bus to signals from gstreamer
        bus.enable_sync_message_emission()
        bus.connect('message', self.on_message)
        bus.connect('sync-message::element', self.on_sync_message)
        return True

    def control(self, event):
        if self.start.GetLabel() == "Start":
            fileid = self.fileid.GetValue()
            if os.path.exists(fileid):
                self.start.SetLabel("Stop")
                fileid = "file://"+unicode(fileid)
                self.player.set_property('uri', fileid)
                self.player.set_state(Gst.State.PLAYING)
            else:
                print "File error - No such file"
        else:
            self.player.set_state(Gst.State.NULL)
            self.start.SetLabel("Start")

    def on_message(self, bus, message):
        t = message.type
        if t == Gst.MessageType.EOS: # media has ended
            self.player.set_state(Gst.State.NULL)
            self.button.SetLabel("Start")
        elif t == Gst.MessageType.ERROR:
            print "Player error"
            self.player.set_state(Gst.State.NULL)
            self.start.SetLabel("Start")

    def on_sync_message(self, bus, message):
        if message.get_structure() is None:
            return True
        message_name = message.get_structure().get_name()
        if message_name == 'prepare-window-handle': #Assign the window id to display in
            imagesink = message.src
            imagesink.set_property('force-aspect-ratio', True) #Force size to fit window
            X_id = self.video_window.GetHandle()
            print ("Window Id:", X_id)
            imagesink.set_window_handle(X_id)
        return True

    def close(self,event):
        self.player.set_state(Gst.State.NULL)
        time.sleep(0.1) #Allow a little time to reach Null state
        event.Skip()

app = Player()
app.MainLoop()

Answer 1

答案是这是一个错误 Bugzilla link

无论是在gstreamer还是Rpi堆栈中，似乎都没有实际意义 解决方法是在playbin管道中指定videosink 所以对于这个特定的程序应该如下：

#!/usr/bin/env python
import os,time
import wx
import gi
gi.require_version('Gst', '1.0')
gi.require_version('GstVideo', '1.0')
from gi.repository import Gst
from gi.repository import GstVideo

class Player(wx.App):

    def OnInit(self):
        window = wx.Frame(None)
        window.SetTitle("Gstreamer Player Test")
        window.SetSize((-1,-1))
        window.Bind(wx.EVT_CLOSE,self.close)
        vbox = wx.BoxSizer(wx.VERTICAL)
        hbox = wx.BoxSizer(wx.HORIZONTAL)
        self.fileid = wx.TextCtrl(window,style=wx.TE_PROCESS_ENTER)
        self.fileid.SetToolTipString("Enter full path to media file")
        hbox.Add(self.fileid, 1)
        self.start = wx.Button(window,label="Start")
        hbox.Add(self.start, 0)
        self.start.Bind(wx.EVT_BUTTON, self.control)
        self.fileid.Bind(wx.EVT_TEXT_ENTER, self.control)
        vbox.Add(hbox, 0, wx.EXPAND, 0)
        video_window = wx.Panel(window)
        vbox.Add(video_window,1,wx.EXPAND,5)
        window.SetSizer(vbox)
        window.Layout()
        window.Show()
        self.SetTopWindow(window)
        Gst.init(None) #initialise gstreamer
        self.X_id = video_window.GetHandle()
        self.player = Gst.ElementFactory.make("playbin", "player")
#        self.ximagesink = Gst.ElementFactory.make("xvimagesink", None)
        self.ximagesink = Gst.ElementFactory.make("ximagesink", None)
        self.player.set_property('video-sink', self.ximagesink)
        bus = self.player.get_bus()
        bus.add_signal_watch() #hook up bus to signals from gstreamer
        bus.enable_sync_message_emission()
        bus.connect('message', self.on_message)
        bus.connect('sync-message::element', self.on_sync_message)
        return True

    def control(self, event):
        if self.start.GetLabel() == "Start":
            fileid = self.fileid.GetValue()
            if os.path.exists(fileid):
                self.start.SetLabel("Stop")
                fileid = "file://"+unicode(fileid)
                self.player.set_property('uri', fileid)
                self.player.set_state(Gst.State.PLAYING)
            else:
                print "File error - No such file"
        else:
            self.player.set_state(Gst.State.NULL)
            self.start.SetLabel("Start")

    def on_message(self, bus, message):
        t = message.type
        if t == Gst.MessageType.EOS: # media has ended
            self.player.set_state(Gst.State.NULL)
            self.button.SetLabel("Start")
        elif t == Gst.MessageType.ERROR:
            print "Player error"
            self.player.set_state(Gst.State.NULL)
            self.start.SetLabel("Start")

    def on_sync_message(self, bus, message):
        if message.get_structure() is None:
            return True
        message_name = message.get_structure().get_name()
        if message_name == 'prepare-window-handle': #Assign the window id to display in
            imagesink = message.src
       #     imagesink.set_property('force-aspect-ratio', True) #Defaults anyway
            imagesink.set_window_handle(self.X_id)
        return True

    def close(self,event):
        self.player.set_state(Gst.State.NULL)
        time.sleep(0.1) #Allow a little time to reach Null state
        event.Skip()

app = Player()
app.MainLoop()

但是，如果您在LibreOffice宏中使用“com.sun.star.comp.avmedia.Manager_GStreamer”时遇到同样的问题，那么这对您没有任何好处，因为Libreoffice开发人员做出了与我相同的假设。似乎无法从Libreoffice中定义视频链接。在这种情况下，我们只需要等到错误修复进入一般版本。

注意：使用ximagesink
使用xvimagesink会在Raspbian上出错，因为Xv软件存在无法使用适配器的问题 使用glimagesink为我们提供了卡在屏幕中间的可怕窗口，似乎eglesssink已经悄然退出服务，因为它不再包含在Raspberry上的gstreamer插件中。