下面的代码将使测试流显示在 WinForm 的面板控件上。
internal enum videosinktype { glimagesink, d3dvideosink, dshowvideosink, directdrawsink}
static Element mVideoTestSource, mVideoCaps, mVideoSink, mAppQueue, mVideoConv;
static Gst.App.AppSink mAppSink;
static System.Threading.Thread mMainGlibThread;
static GLib.MainLoop mMainLoop; // GLib's Main Loop
private const videosinktype mCfgVideosinkType = videosinktype.dshowvideosink;
private ulong mHandle;
private Gst.Video.VideoSink mGlImageSink;
private Gst.Pipeline mCurrentPipeline = null;
private void InitGStreamerPipeline()
{
//Assign Handle to prevent Cross-Threading Access
mHandle = (ulong)videoDisplay.Handle;
//Init Gstreamer
Gst.Application.Init();
GtkSharp.GstreamerSharp.ObjectManager.Initialize();
mMainLoop = new GLib.MainLoop();
mMainGlibThread = new System.Threading.Thread(mMainLoop.Run);
mMainGlibThread.Start();
#region BuildPipeline
switch (mCfgVideosinkType)
{
case videosinktype.glimagesink:
mGlImageSink = (Gst.Video.VideoSink)Gst.ElementFactory.Make("glimagesink", "glimagesink");
break;
case videosinktype.d3dvideosink:
mGlImageSink = (Gst.Video.VideoSink)Gst.ElementFactory.Make("d3dvideosink", "d3dvideosink");
//mGlImageSink = (Gst.Video.VideoSink)Gst.ElementFactory.Make("dshowvideosink", "dshowvideosink");
break;
case videosinktype.dshowvideosink:
mGlImageSink = (Gst.Video.VideoSink)Gst.ElementFactory.Make("dshowvideosink", "dshowvideosink");
break;
case videosinktype.directdrawsink:
mGlImageSink = (Gst.Video.VideoSink)Gst.ElementFactory.Make("directdrawsink", "directdrawsink");
break;
default:
break;
}
mVideoTestSource = ElementFactory.Make("videotestsrc", "videotestsrc0");
mVideoConv = ElementFactory.Make("videoconvert", "vidconvert0");
mVideoSink = ElementFactory.Make("autovideosink", "sink0");
mCurrentPipeline = new Gst.Pipeline("pipeline");
mCurrentPipeline.Add(mVideoTestSource, mVideoConv, mVideoSink, mGlImageSink);
if (!mVideoTestSource.Link(mVideoSink))
if (mUdpcSrc.Link(mVideoSink))
{
System.Diagnostics.Debug.WriteLine("Elements could not be linked");
}
#endregion
//subscribe to bus & bussync msgs
Bus bus = mCurrentPipeline.Bus;
bus.AddSignalWatch();
bus.Message += HandleMessage;
Bus bus = mCurrentPipeline.Bus;
bus.EnableSyncMessageEmission();
bus.SyncMessage += new SyncMessageHandler(bus_SyncMessage);
//play the stream
var setStateRet = mCurrentPipeline.SetState(State.Null);
System.Diagnostics.Debug.WriteLine("SetStateNULL returned: " + setStateRet.ToString());
setStateRet = mCurrentPipeline.SetState(State.Ready);
System.Diagnostics.Debug.WriteLine("SetStateReady returned: " + setStateRet.ToString());
setStateRet = mCurrentPipeline.SetState(Gst.State.Playing);
}
/// <summary>
///
/// </summary>
/// <remarks>
/// Indeed the application needs to set its Window identifier at the right time to avoid internal Window creation
/// from the video sink element. To solve this issue a GstMessage is posted on the bus to inform the application
/// that it should set the Window identifier immediately.
///
/// API: http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-gstvideooverlay.html
/// </remarks>
/// <param name="o"></param>
/// <param name="args"></param>
private void bus_SyncMessage(object o, SyncMessageArgs args)
{
//Convenience function to check if the given message is a "prepare-window-handle" message from a GstVideoOverlay.
System.Diagnostics.Debug.WriteLine("bus_SyncMessage: " + args.Message.Type.ToString());
if (Gst.Video.Global.IsVideoOverlayPrepareWindowHandleMessage(args.Message))
{
Element src = (Gst.Element)args.Message.Src;
#if DEBUG
System.Diagnostics.Debug.WriteLine("Message'prepare-window-handle' received by: " + src.Name + " " + src.ToString());
#endif
if (src != null && (src is Gst.Video.VideoSink | src is Gst.Bin))
{
// Try to set Aspect Ratio
try
{
src["force-aspect-ratio"] = true;
}
catch (PropertyNotFoundException) { }
// Try to set Overlay
try
{
Gst.Video.VideoOverlayAdapter overlay_ = new Gst.Video.VideoOverlayAdapter(src.Handle);
overlay_.WindowHandle = mHandle;
overlay_.HandleEvents(true);
}
catch (Exception ex) { System.Diagnostics.Debug.WriteLine("Exception thrown: " + ex.Message); }
}
}
}
private void HandleMessage (object o, MessageArgs args)
{
var msg = args.Message;
//System.Diagnostics.Debug.WriteLine("HandleMessage received msg of type: {0}", msg.Type);
switch (msg.Type)
{
case MessageType.Error:
//
GLib.GException err;
string debug;
System.Diagnostics.Debug.WriteLine("Error received: " + msg.ToString());
//msg.ParseError (out err, out debug);
//if(debug == null) { debug = "none"; }
//System.Diagnostics.Debug.WriteLine ("Error received from element {0}: {1}", msg.Src, err.Message);
//System.Diagnostics.Debug.WriteLine ("Debugging information: "+ debug);
break;
case MessageType.StreamStatus:
Gst.StreamStatusType status;
Element theOwner;
msg.ParseStreamStatus(out status, out theOwner);
System.Diagnostics.Debug.WriteLine("Case SteamingStatus: status is: " + status + " ; Ownder is: " + theOwner.Name);
break;
case MessageType.StateChanged:
//System.Diagnostics.Debug.WriteLine("Case StateChanged: " + args.Message.ToString());
State oldState, newState, pendingState;
msg.ParseStateChanged(out oldState, out newState, out pendingState);
if (newState == State.Paused)
args.RetVal = false;
System.Diagnostics.Debug.WriteLine("Pipeline state changed from {0} to {1}: ; Pending: {2}", Element.StateGetName(oldState), Element.StateGetName(newState), Element.StateGetName(pendingState));
break;
case MessageType.Element:
System.Diagnostics.Debug.WriteLine("Element message: {0}", args.Message.ToString());
break;
default:
System.Diagnostics.Debug.WriteLine("HandleMessage received msg of type: {0}", msg.Type);
break;
}
args.RetVal = true;
}