[DllImport ("gstreamer-0.10.dll") ]
private static extern bool gst_pad_query_position (IntPtr raw, ref Format format, out long cur);

public bool QueryPosition (Gst.Format format, out long current) {
  return gst_pad_query_position (Handle, ref format, out current);
}

[DllImport ("gstreamer-0.10.dll") ]
private static extern bool gst_pad_query_duration (IntPtr raw, ref Format format, out long duration);

public bool QueryDuration (Gst.Format format, out long duration) {
  return gst_pad_query_duration (Handle, ref format, out duration);
}


public delegate bool BufferProbeDelegate (Pad pad, Gst.Buffer buffer);
internal delegate bool BufferProbeNativeDelegate (IntPtr pad, IntPtr buf, IntPtr data);

internal class BufferProbeWrapper {
  internal BufferProbeNativeDelegate NativeFunc;
  BufferProbeDelegate managedFunc;

  public BufferProbeWrapper (BufferProbeDelegate func) {
    managedFunc = func;
    if (func != null)
      NativeFunc = new BufferProbeNativeDelegate (BufferProbeMarshaller);
  }

  public bool BufferProbeMarshaller (IntPtr raw_pad, IntPtr buf, IntPtr data) {
    Pad pad = GLib.Object.GetObject (raw_pad) as Pad;
    Gst.Buffer buffer = GLib.Opaque.GetOpaque (buf, typeof (Gst.Buffer), false) as Gst.Buffer;
    return (bool) (managedFunc (pad, buffer));
  }
}

[DllImport ("gstreamer-0.10.dll") ]
private static extern ulong gst_pad_add_buffer_probe (IntPtr pad, BufferProbeNativeDelegate func, IntPtr data);

public ulong AddBufferProbe (BufferProbeDelegate func) {
  BufferProbeWrapper func_wrapper;
  if (PersistentData["AddBufferProbe"] != null) {
    func_wrapper = PersistentData["AddBufferProbe"] as BufferProbeWrapper;
  } else {
    func_wrapper = new BufferProbeWrapper (func);
    PersistentData["AddBufferProbe"] = func_wrapper;
  }

  return gst_pad_add_buffer_probe (this.Handle, func_wrapper.NativeFunc, IntPtr.Zero);
}

[DllImport ("gstreamer-0.10.dll") ]
private static extern void gst_pad_remove_buffer_probe (IntPtr pad, uint handler_id);

public void RemoveBufferProbe (uint handler_id) {
  gst_pad_remove_buffer_probe (this.Handle, handler_id);
  PersistentData["AddBufferProbe"] = null;
}

public delegate bool DataProbeDelegate (Pad pad, GLib.Opaque miniobject);
internal delegate bool DataProbeNativeDelegate (IntPtr pad, IntPtr miniobj, IntPtr data);

internal class DataProbeWrapper {
  internal DataProbeNativeDelegate NativeFunc;
  DataProbeDelegate ManagedFunc;

  public DataProbeWrapper (DataProbeDelegate func) {
    ManagedFunc = func;
    if (func != null)
      NativeFunc = new DataProbeNativeDelegate (DataProbeMarshaller);
  }

  public bool DataProbeMarshaller (IntPtr raw_pad, IntPtr miniobj, IntPtr data) {
    Pad pad = GLib.Object.GetObject (raw_pad) as Pad;
    GLib.Opaque opaque = GLib.Opaque.GetOpaque (miniobj, typeof (GLib.Opaque), true);
    return ManagedFunc (pad, opaque);
  }
}

[DllImport ("gstreamer-0.10.dll") ]
static extern uint gst_pad_add_data_probe (IntPtr pad, DataProbeNativeDelegate func, IntPtr data);

public uint AddDataProbe (DataProbeDelegate func) {
  DataProbeWrapper func_wrapper;
  if (PersistentData["AddDataProbe"] != null) {
    func_wrapper = PersistentData["AddDataProbe"] as DataProbeWrapper;
  } else {
    func_wrapper = new DataProbeWrapper (func);
    PersistentData["AddDataProbe"] = func_wrapper;
  }

  return gst_pad_add_data_probe (this.Handle, func_wrapper.NativeFunc, IntPtr.Zero);
}

[DllImport ("gstreamer-0.10.dll") ]
static extern void gst_pad_remove_data_probe (IntPtr pad, uint handler_id);

public void RemoveDataProbe (uint handler_id) {
  gst_pad_remove_data_probe (this.Handle, handler_id);
  PersistentData["AddDataProbe"] = null;
}