removed unneeded mutex from ffmpeg decoder

Vocaluxe/Lib/Video/CVideoDecoderFFmpeg.cs

@@ -260,7 +260,6 @@ namespace Vocaluxe.Lib.Video
         AutoResetEvent EventDecode = new AutoResetEvent(false);
         SFrameBuffer[] _FrameBuffer = new SFrameBuffer[5];
         Object MutexFramebuffer = new Object();
-        Object MutexFrame = new Object();
         Object MutexSyncSignals = new Object();
 
         public Decoder()
@@ -594,8 +593,6 @@ namespace Vocaluxe.Lib.Video
             }
 
             if (!_BeforeLoop && (!DropFrame || FrameFinished != 0))
-            {
-                lock (MutexFrame)
             {
                 try
                 {
@@ -605,8 +602,6 @@ namespace Vocaluxe.Lib.Video
                 {
                     CLog.LogError("Error AcGetFrame " + _FileName);
                 }
-                    
-                }
             }
 
             if (FrameFinished == 0)
@@ -672,9 +667,6 @@ namespace Vocaluxe.Lib.Video
                 if (num == -1)
                     _waiting = true;
                 else
-                {
-
-                    lock (MutexFrame)
                 {
                     TAc_decoder Videodecoder = (TAc_decoder)Marshal.PtrToStructure(_videodecoder, typeof(TAc_decoder));
 
@@ -687,8 +679,6 @@ namespace Vocaluxe.Lib.Video
                             
                         _FrameBuffer[num].displayed = false;
                     }
-                    }
-                   
                
                     _waiting = false;
                 }