merge with current trunk (just update)

git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/branches/experimental@1634 b956fd51-792f-4845-bead-9b4dfca2ff2c

8 files changed, 174 insertions, 117 deletions

diff --git a/unicode/src/media/UAudioConverter.pas b/unicode/src/media/UAudioConverter.pas
index 24131b16..657b80dd 100644
--- a/unicode/src/media/UAudioConverter.pas
+++ b/unicode/src/media/UAudioConverter.pas
@@ -70,7 +70,7 @@ type
       function Init(SrcFormatInfo: TAudioFormatInfo; DstFormatInfo: TAudioFormatInfo): boolean; override;
       destructor Destroy(); override;
 
-      function Convert(InputBuffer: PChar; OutputBuffer: PChar; var InputSize: integer): integer; override;
+      function Convert(InputBuffer: PByteArray; OutputBuffer: PByteArray; var InputSize: integer): integer; override;
       function GetOutputBufferSize(InputSize: integer): integer; override;
       function GetRatio(): double; override;
   end;
@@ -87,7 +87,7 @@ type
       function Init(SrcFormatInfo: TAudioFormatInfo; DstFormatInfo: TAudioFormatInfo): boolean; override;
       destructor Destroy(); override;
 
-      function Convert(InputBuffer: PChar; OutputBuffer: PChar; var InputSize: integer): integer; override;
+      function Convert(InputBuffer: PByteArray; OutputBuffer: PByteArray; var InputSize: integer): integer; override;
       function GetOutputBufferSize(InputSize: integer): integer; override;
       function GetRatio(): double; override;
   end;
@@ -103,7 +103,7 @@ type
       function Init(SrcFormatInfo: TAudioFormatInfo; DstFormatInfo: TAudioFormatInfo): boolean; override;
       destructor Destroy(); override;
 
-      function Convert(InputBuffer: PChar; OutputBuffer: PChar; var InputSize: integer): integer; override;
+      function Convert(InputBuffer: PByteArray; OutputBuffer: PByteArray; var InputSize: integer): integer; override;
       function GetOutputBufferSize(InputSize: integer): integer; override;
       function GetRatio(): double; override;
   end;
@@ -173,7 +173,7 @@ begin
   Result := cvt.len_ratio;
 end;
 
-function TAudioConverter_SDL.Convert(InputBuffer: PChar; OutputBuffer: PChar; var InputSize: integer): integer;
+function TAudioConverter_SDL.Convert(InputBuffer: PByteArray; OutputBuffer: PByteArray; var InputSize: integer): integer;
 begin
   Result := -1;
 
@@ -242,7 +242,7 @@ begin
   inherited;
 end;
 
-function TAudioConverter_FFmpeg.Convert(InputBuffer: PChar; OutputBuffer: PChar; var InputSize: integer): integer;
+function TAudioConverter_FFmpeg.Convert(InputBuffer: PByteArray; OutputBuffer: PByteArray; var InputSize: integer): integer;
 var
   InputSampleCount: integer;
   OutputSampleCount: integer;
@@ -360,11 +360,11 @@ begin
   inherited;
 end;
 
-function TAudioConverter_SRC.Convert(InputBuffer: PChar; OutputBuffer: PChar; var InputSize: integer): integer;
+function TAudioConverter_SRC.Convert(InputBuffer: PByteArray; OutputBuffer: PByteArray; var InputSize: integer): integer;
 var
   FloatInputBuffer: PSingle;
   FloatOutputBuffer: PSingle;
-  TempBuffer: PChar;
+  TempBuffer: PByteArray;
   TempSize: integer;
   NumSamples: integer;
   OutputSize: integer;
diff --git a/unicode/src/media/UAudioDecoder_Bass.pas b/unicode/src/media/UAudioDecoder_Bass.pas
index 3c31175d..6bbdaeaa 100644
--- a/unicode/src/media/UAudioDecoder_Bass.pas
+++ b/unicode/src/media/UAudioDecoder_Bass.pas
@@ -65,7 +65,7 @@ type
       function IsEOF(): boolean;             override;
       function IsError(): boolean;           override;
 
-      function ReadData(Buffer: PChar; BufSize: integer): integer; override;
+      function ReadData(Buffer: PByteArray; BufSize: integer): integer; override;
   end;
 
 type
@@ -193,7 +193,7 @@ begin
   Result := Error;
 end;
 
-function TBassDecodeStream.ReadData(Buffer: PChar; BufSize: integer): integer;
+function TBassDecodeStream.ReadData(Buffer: PByteArray; BufSize: integer): integer;
 begin
   Result := BASS_ChannelGetData(Handle, Buffer, BufSize);
   // check error state (do not handle EOF as error)
@@ -237,7 +237,7 @@ begin
 
   // TODO: use BASS_STREAM_PRESCAN for accurate seeking in VBR-files?
   //       disadvantage: seeking will slow down.
-  Stream := BASS_StreamCreateFile(False, PChar(Filename), 0, 0, BASS_STREAM_DECODE);
+  Stream := BASS_StreamCreateFile(False, PAnsiChar(Filename), 0, 0, BASS_STREAM_DECODE);
   if (Stream = 0) then
   begin
     //Log.LogError(BassCore.ErrorGetString(), 'TAudioDecoder_Bass.Open');
diff --git a/unicode/src/media/UAudioDecoder_FFmpeg.pas b/unicode/src/media/UAudioDecoder_FFmpeg.pas
index 399c2f52..2d221f40 100644
--- a/unicode/src/media/UAudioDecoder_FFmpeg.pas
+++ b/unicode/src/media/UAudioDecoder_FFmpeg.pas
@@ -57,7 +57,6 @@ implementation
 
 uses
   Classes,
-  SysUtils,
   Math,
   UMusic,
   UIni,
@@ -68,8 +67,9 @@ uses
   avio,
   mathematics, // used for av_rescale_q
   rational,
-  UMediaCore_FFmpeg,
   SDL,
+  SysUtils,
+  UMediaCore_FFmpeg,
   ULog,
   UCommon,
   UConfig;
@@ -129,14 +129,14 @@ type
 
       // state-vars for DecodeFrame (locked by DecoderLock)
       AudioPaket:        TAVPacket;
-      AudioPaketData:    PChar;
+      AudioPaketData:    PByteArray;
       AudioPaketSize:    integer;
       AudioPaketSilence: integer; // number of bytes of silence to return
 
       // state-vars for AudioCallback (locked by DecoderLock)
       AudioBufferPos:  integer;
       AudioBufferSize: integer;
-      AudioBuffer:     PChar;
+      AudioBuffer:     PByteArray;
 
       Filename: string;
 
@@ -153,7 +153,7 @@ type
       procedure PauseParser();
       procedure ResumeParser();
 
-      function DecodeFrame(Buffer: PChar; BufferSize: integer): integer;
+      function DecodeFrame(Buffer: PByteArray; BufferSize: integer): integer;
       procedure FlushCodecBuffers();
       procedure PauseDecoder();
       procedure ResumeDecoder();
@@ -173,11 +173,11 @@ type
       function IsEOF(): boolean;             override;
       function IsError(): boolean;           override;
 
-      function ReadData(Buffer: PChar; BufferSize: integer): integer; override;
+      function ReadData(Buffer: PByteArray; BufferSize: integer): integer; override;
   end;
 
 type
-  TAudioDecoder_FFmpeg = class( TInterfacedObject, IAudioDecoder )
+  TAudioDecoder_FFmpeg = class(TInterfacedObject, IAudioDecoder)
     public
       function GetName: string;
 
@@ -289,7 +289,7 @@ begin
   Self.Filename := Filename;
 
   // open audio file
-  if (av_open_input_file(FormatCtx, PChar(Filename), nil, 0, nil) <> 0) then
+  if (av_open_input_file(FormatCtx, PAnsiChar(Filename), nil, 0, nil) <> 0) then
   begin
     Log.LogError('av_open_input_file failed: "' + Filename + '"', 'UAudio_FFmpeg');
     Exit;
@@ -310,7 +310,7 @@ begin
   FormatCtx^.pb.eof_reached := 0;
 
   {$IFDEF DebugFFmpegDecode}
-  dump_format(FormatCtx, 0, pchar(Filename), 0);
+  dump_format(FormatCtx, 0, PAnsiChar(Filename), 0);
   {$ENDIF}
 
   AudioStreamIndex := FFmpegCore.FindAudioStreamIndex(FormatCtx);
@@ -862,7 +862,7 @@ begin
   end;
 end;
 
-function TFFmpegDecodeStream.DecodeFrame(Buffer: PChar; BufferSize: integer): integer;
+function TFFmpegDecodeStream.DecodeFrame(Buffer: PByteArray; BufferSize: integer): integer;
 var
   PaketDecodedSize: integer; // size of packet data used for decoding
   DataSize: integer;         // size of output data decoded by FFmpeg
@@ -945,7 +945,7 @@ begin
       Exit;
 
     // handle Status-packet
-    if (PChar(AudioPaket.data) = STATUS_PACKET) then
+    if (PAnsiChar(AudioPaket.data) = STATUS_PACKET) then
     begin
       AudioPaket.data := nil;
       AudioPaketData := nil;
@@ -986,7 +986,7 @@ begin
       Continue;
     end;
 
-    AudioPaketData := PChar(AudioPaket.data);
+    AudioPaketData := AudioPaket.data;
     AudioPaketSize := AudioPaket.size;
 
     // if available, update the stream position to the presentation time of this package
@@ -1005,7 +1005,7 @@ begin
   end;
 end;
 
-function TFFmpegDecodeStream.ReadData(Buffer: PChar; BufferSize: integer): integer;
+function TFFmpegDecodeStream.ReadData(Buffer: PByteArray; BufferSize: integer): integer;
 var
   CopyByteCount:   integer; // number of bytes to copy
   RemainByteCount: integer; // number of bytes left (remain) to read
diff --git a/unicode/src/media/UAudioPlayback_Bass.pas b/unicode/src/media/UAudioPlayback_Bass.pas
index d68ac1d4..923c1d7b 100644
--- a/unicode/src/media/UAudioPlayback_Bass.pas
+++ b/unicode/src/media/UAudioPlayback_Bass.pas
@@ -37,7 +37,6 @@ implementation
 
 uses
   Classes,
-  SysUtils,
   Math,
   UIni,
   UMain,
@@ -46,7 +45,8 @@ uses
   UAudioCore_Bass,
   ULog,
   sdl,
-  bass;
+  bass,
+  SysUtils;
 
 type
   PHDSP = ^HDSP;
@@ -90,7 +90,7 @@ type
 
       function GetAudioFormatInfo(): TAudioFormatInfo; override;
 
-      function ReadData(Buffer: PChar; BufferSize: integer): integer;
+      function ReadData(Buffer: PByteArray; BufferSize: integer): integer;
 
       property EOF: boolean READ IsEOF;
   end;
@@ -106,8 +106,8 @@ type
       function Open(ChannelMap: integer; FormatInfo: TAudioFormatInfo): boolean; override;
       procedure Close(); override;
 
-      procedure WriteData(Buffer: PChar; BufferSize: integer); override;
-      function ReadData(Buffer: PChar; BufferSize: integer): integer; override;
+      procedure WriteData(Buffer: PByteArray; BufferSize: integer); override;
+      function ReadData(Buffer: PByteArray; BufferSize: integer): integer; override;
       function IsEOF(): boolean; override;
       function IsError(): boolean; override;
   end;
@@ -163,14 +163,14 @@ begin
     Result := BytesRead;
 end;
 
-function TBassPlaybackStream.ReadData(Buffer: PChar; BufferSize: integer): integer;
+function TBassPlaybackStream.ReadData(Buffer: PByteArray; BufferSize: integer): integer;
 var
   AdjustedSize: integer;
   RequestedSourceSize, SourceSize: integer;
   SkipCount: integer;
   SourceFormatInfo: TAudioFormatInfo;
   FrameSize: integer;
-  PadFrame: PChar;
+  PadFrame: PByteArray;
   //Info: BASS_INFO;
   //Latency: double;
 begin
@@ -610,7 +610,7 @@ begin
   inherited Close();
 end;
 
-procedure TBassVoiceStream.WriteData(Buffer: PChar; BufferSize: integer);
+procedure TBassVoiceStream.WriteData(Buffer: PByteArray; BufferSize: integer);
 var QueueSize: DWORD;
 begin
   if ((Handle <> 0) and (BufferSize > 0)) then
@@ -626,7 +626,7 @@ begin
 end;
 
 // Note: we do not need the read-function for the BASS implementation
-function TBassVoiceStream.ReadData(Buffer: PChar; BufferSize: integer): integer;
+function TBassVoiceStream.ReadData(Buffer: PByteArray; BufferSize: integer): integer;
 begin
   Result := -1;
 end;
diff --git a/unicode/src/media/UAudioPlayback_SDL.pas b/unicode/src/media/UAudioPlayback_SDL.pas
index b0887676..8403ef03 100644
--- a/unicode/src/media/UAudioPlayback_SDL.pas
+++ b/unicode/src/media/UAudioPlayback_SDL.pas
@@ -33,16 +33,14 @@ interface
 
 {$I switches.inc}
 
-uses
-  Classes,
-  SysUtils,
-  UMusic;
-
 implementation
 
 uses
+  Classes,
   sdl,
+  SysUtils,
   UAudioPlayback_SoftMixer,
+  UMusic,
   ULog,
   UIni,
   UMain;
@@ -60,13 +58,13 @@ type
       function GetLatency(): double;                     override;
     public
       function GetName: String;                          override;
-      procedure MixBuffers(dst, src: PChar; size: Cardinal; volume: Single); override;
+      procedure MixBuffers(dst, src: PByteArray; size: Cardinal; volume: Single); override;
   end;
 
   
 { TAudioPlayback_SDL }
 
-procedure SDLAudioCallback(userdata: Pointer; stream: PChar; len: integer); cdecl;
+procedure SDLAudioCallback(userdata: Pointer; stream: PByteArray; len: integer); cdecl;
 var
   Engine: TAudioPlayback_SDL;
 begin
@@ -172,7 +170,7 @@ begin
   Result := Latency;
 end;
 
-procedure TAudioPlayback_SDL.MixBuffers(dst, src: PChar; size: Cardinal; volume: Single);
+procedure TAudioPlayback_SDL.MixBuffers(dst, src: PByteArray; size: Cardinal; volume: Single);
 begin
   SDL_MixAudio(PUInt8(dst), PUInt8(src), size, Round(volume * SDL_MIX_MAXVOLUME));
 end;
diff --git a/unicode/src/media/UAudioPlayback_SoftMixer.pas b/unicode/src/media/UAudioPlayback_SoftMixer.pas
index f3797dd6..c8da6bcd 100644
--- a/unicode/src/media/UAudioPlayback_SoftMixer.pas
+++ b/unicode/src/media/UAudioPlayback_SoftMixer.pas
@@ -35,8 +35,8 @@ interface
 
 uses
   Classes,
-  SysUtils,
   sdl,
+  SysUtils,
   URingBuffer,
   UMusic,
   UAudioPlaybackBase;
@@ -48,12 +48,12 @@ type
     private
       Engine: TAudioPlayback_SoftMixer;
 
-      SampleBuffer:      PChar;
+      SampleBuffer:      PByteArray;
       SampleBufferSize:  integer;
       SampleBufferCount: integer; // number of available bytes in SampleBuffer
       SampleBufferPos:   cardinal;
 
-      SourceBuffer:      PChar;
+      SourceBuffer:      PByteArray;
       SourceBufferSize:  integer;
       SourceBufferCount: integer; // number of available bytes in SourceBuffer
 
@@ -70,7 +70,7 @@ type
 
       procedure Reset();
 
-      procedure ApplySoundEffects(Buffer: PChar; BufferSize: integer);
+      procedure ApplySoundEffects(Buffer: PByteArray; BufferSize: integer);
       function InitFormatConversion(): boolean;
       procedure FlushBuffers();
 
@@ -100,7 +100,7 @@ type
 
       function GetAudioFormatInfo(): TAudioFormatInfo; override;
 
-      function ReadData(Buffer: PChar; BufferSize: integer): integer;
+      function ReadData(Buffer: PByteArray; BufferSize: integer): integer;
 
       function GetPCMData(var Data: TPCMData): Cardinal; override;
       procedure GetFFTData(var Data: TFFTData);          override;
@@ -114,7 +114,7 @@ type
       Engine: TAudioPlayback_SoftMixer;
 
       ActiveStreams: TList;
-      MixerBuffer: PChar;
+      MixerBuffer: PByteArray;
       InternalLock: PSDL_Mutex;
 
       AppVolume: single;
@@ -129,7 +129,7 @@ type
       destructor Destroy(); override;
       procedure AddStream(Stream: TAudioPlaybackStream);
       procedure RemoveStream(Stream: TAudioPlaybackStream);
-      function ReadData(Buffer: PChar; BufferSize: integer): integer;
+      function ReadData(Buffer: PByteArray; BufferSize: integer): integer;
 
       property Volume: single read GetVolume write SetVolume;
   end;
@@ -144,7 +144,7 @@ type
       function StartAudioPlaybackEngine(): boolean;      virtual; abstract;
       procedure StopAudioPlaybackEngine();               virtual; abstract;
       function FinalizeAudioPlaybackEngine(): boolean;   virtual; abstract;
-      procedure AudioCallback(Buffer: PChar; Size: integer); {$IFDEF HasInline}inline;{$ENDIF}
+      procedure AudioCallback(Buffer: PByteArray; Size: integer); {$IFDEF HasInline}inline;{$ENDIF}
 
       function CreatePlaybackStream(): TAudioPlaybackStream; override;
     public
@@ -159,7 +159,7 @@ type
       function GetMixer(): TAudioMixerStream; {$IFDEF HasInline}inline;{$ENDIF}
       function GetAudioFormatInfo(): TAudioFormatInfo;
 
-      procedure MixBuffers(DstBuffer, SrcBuffer: PChar; Size: Cardinal; Volume: Single); virtual;
+      procedure MixBuffers(DstBuffer, SrcBuffer: PByteArray; Size: Cardinal; Volume: Single); virtual;
   end;
 
 type
@@ -174,8 +174,8 @@ type
 
       function Open(ChannelMap: integer; FormatInfo: TAudioFormatInfo): boolean; override;
       procedure Close(); override;
-      procedure WriteData(Buffer: PChar; BufferSize: integer); override;
-      function ReadData(Buffer: PChar; BufferSize: integer): integer; override;
+      procedure WriteData(Buffer: PByteArray; BufferSize: integer); override;
+      function ReadData(Buffer: PByteArray; BufferSize: integer): integer; override;
       function IsEOF(): boolean; override;
       function IsError(): boolean; override;
   end;
@@ -276,7 +276,7 @@ begin
   Unlock();
 end;
 
-function TAudioMixerStream.ReadData(Buffer: PChar; BufferSize: integer): integer;
+function TAudioMixerStream.ReadData(Buffer: PByteArray; BufferSize: integer): integer;
 var
   i: integer;
   Size: integer;
@@ -545,7 +545,7 @@ begin
   SourceBufferCount := 0;
 end;
 
-procedure TGenericPlaybackStream.ApplySoundEffects(Buffer: PChar; BufferSize: integer);
+procedure TGenericPlaybackStream.ApplySoundEffects(Buffer: PByteArray; BufferSize: integer);
 var
   i: integer;
 begin
@@ -558,7 +558,7 @@ begin
   end;
 end;
 
-function TGenericPlaybackStream.ReadData(Buffer: PChar; BufferSize: integer): integer;
+function TGenericPlaybackStream.ReadData(Buffer: PByteArray; BufferSize: integer): integer;
 var
   ConversionInputCount: integer;
   ConversionOutputSize: integer;   // max. number of converted data (= buffer size)
@@ -573,7 +573,7 @@ var
   SkipSourceCount: integer;  // number of source-data bytes to skip
   FillCount: integer;  // number of bytes to fill with padding data
   CopyCount: integer;
-  PadFrame: PChar;
+  PadFrame: PByteArray;
   i: integer;
 begin
   Result := -1;
@@ -986,7 +986,7 @@ begin
   inherited Close();
 end;
 
-procedure TGenericVoiceStream.WriteData(Buffer: PChar; BufferSize: integer);
+procedure TGenericVoiceStream.WriteData(Buffer: PByteArray; BufferSize: integer);
 begin
   // lock access to buffer
   SDL_mutexP(BufferLock);
@@ -999,7 +999,7 @@ begin
   end;
 end;
 
-function TGenericVoiceStream.ReadData(Buffer: PChar; BufferSize: integer): integer;
+function TGenericVoiceStream.ReadData(Buffer: PByteArray; BufferSize: integer): integer;
 begin
   Result := -1;
 
@@ -1059,7 +1059,7 @@ begin
   Result := true;
 end;
 
-procedure TAudioPlayback_SoftMixer.AudioCallback(Buffer: PChar; Size: integer);
+procedure TAudioPlayback_SoftMixer.AudioCallback(Buffer: PByteArray; Size: integer);
 begin
   MixerStream.ReadData(Buffer, Size);
 end;
@@ -1102,7 +1102,7 @@ begin
   MixerStream.Volume := Volume;
 end;
 
-procedure TAudioPlayback_SoftMixer.MixBuffers(DstBuffer, SrcBuffer: PChar; Size: Cardinal; Volume: Single);
+procedure TAudioPlayback_SoftMixer.MixBuffers(DstBuffer, SrcBuffer: PByteArray; Size: Cardinal; Volume: Single);
 var
   SampleIndex: Cardinal;
   SampleInt: Integer;
diff --git a/unicode/src/media/UVideo.pas b/unicode/src/media/UVideo.pas
index 06577d9e..35f8ab4d 100644
--- a/unicode/src/media/UVideo.pas
+++ b/unicode/src/media/UVideo.pas
@@ -126,6 +126,7 @@ type
 
     fFrameBuffer: PByte;  //**< stores a FFmpeg video frame
     fFrameTex:    GLuint; //**< OpenGL texture for FrameBuffer
+    fFrameTexValid: boolean; //**< if true, fFrameTex contains the current frame
     fTexWidth, fTexHeight: cardinal;
 
     {$IFDEF UseSWScale}
@@ -137,11 +138,11 @@ type
     
     fTimeBase: extended;  //**< FFmpeg time base per time unit
     fTime:     extended;  //**< video time position (absolute)
-    fLoopTime: extended;  //**< video time position (relative to current loop)
+    fLoopTime: extended;  //**< start time of the current loop
 
     procedure Reset();
-    function DecodeFrame(var AVPacket: TAVPacket; out pts: double): boolean;
-    procedure SynchronizeVideo(Frame: PAVFrame; var pts: double);
+    function DecodeFrame(): boolean;
+    procedure SynchronizeTime(Frame: PAVFrame; var pts: double);
 
     procedure GetVideoRect(var ScreenRect, TexRect: TRectCoords);
     
@@ -240,6 +241,7 @@ begin
   fTime          := 0;
   fStream := nil;
   fStreamIndex := -1;
+  fFrameTexValid := false;
 
   fEOF := false;
 
@@ -453,7 +455,7 @@ begin
   fOpened := False;
 end;
 
-procedure TVideoPlayback_FFmpeg.SynchronizeVideo(Frame: PAVFrame; var pts: double);
+procedure TVideoPlayback_FFmpeg.SynchronizeTime(Frame: PAVFrame; var pts: double);
 var
   FrameDelay: double;
 begin
@@ -473,12 +475,21 @@ begin
   fTime := fTime + FrameDelay;
 end;
 
-function TVideoPlayback_FFmpeg.DecodeFrame(var AVPacket: TAVPacket; out pts: double): boolean;
+{**
+ * Decode a new frame from the video stream.
+ * The decoded frame is stored in fAVFrame. fTime is updated to the new frame's
+ * time.
+ * @param pts will be updated to the presentation time of the decoded frame. 
+ * returns true if a frame could be decoded. False if an error or EOF occured.
+ *}
+function TVideoPlayback_FFmpeg.DecodeFrame(): boolean;
 var
   FrameFinished: Integer;
   VideoPktPts: int64;
   pbIOCtx: PByteIOContext;
   errnum: integer;
+  AVPacket: TAVPacket;
+  pts: double;
 begin
   Result := false;
   FrameFinished := 0;
@@ -521,8 +532,17 @@ begin
       end;
 
       // no error -> wait for user input
-      SDL_Delay(100);
+{
+      SDL_Delay(100);  // initial version, left for documentation
       continue;
+}
+
+      // Patch by Hawkear:
+      // Why should this function loop in an endless loop if there is an error?
+      // This runs in the main thread, so it halts the whole program
+      // Therefore, it is better to exit when an error occurs
+      Exit;
+
     end;
 
     // if we got a packet from the video stream, then decode it
@@ -555,9 +575,9 @@ begin
       end;
       pts := pts * av_q2d(fStream^.time_base);
 
-      // synchronize on each complete frame
+      // synchronize time on each complete frame
       if (frameFinished <> 0) then
-        SynchronizeVideo(fAVFrame, pts);
+        SynchronizeTime(fAVFrame, pts);
     end;
 
     // free the packet from av_read_frame
@@ -569,13 +589,12 @@ end;
 
 procedure TVideoPlayback_FFmpeg.GetFrame(Time: Extended);
 var
-  AVPacket: TAVPacket;
   errnum: Integer;
-  myTime: Extended;
+  NewTime: Extended;
   TimeDifference: Extended;
   DropFrameCount: Integer;
-  pts: double;
   i: Integer;
+  Success: boolean;
 const
   FRAME_DROPCOUNT = 3;
 begin
@@ -585,41 +604,50 @@ begin
   if fPaused then
     Exit;
 
-  // current time, relative to last fLoop (if any)
-  myTime := Time - fLoopTime;
-  // time since the last frame was returned
-  TimeDifference := myTime - fTime;
+  // requested stream position (relative to the last loop's start)
+  NewTime := Time - fLoopTime;
 
-  {$IFDEF DebugDisplay}
-  DebugWriteln('Time:      '+inttostr(floor(Time*1000)) + sLineBreak +
-               'VideoTime: '+inttostr(floor(fTime*1000)) + sLineBreak +
-               'TimeBase:  '+inttostr(floor(fTimeBase*1000)) + sLineBreak +
-               'TimeDiff:  '+inttostr(floor(TimeDifference*1000)));
-  {$endif}
-
-  // check if a new frame is needed
-  if (fTime <> 0) and (TimeDifference < fTimeBase) then
+  // check if current texture still contains the active frame
+  if (fFrameTexValid) then
   begin
-    {$ifdef DebugFrames}
-    // frame delay debug display
-    GoldenRec.Spawn(200,15,1,16,0,-1,ColoredStar,$00ff00);
-    {$endif}
+    // time since the last frame was returned
+    TimeDifference := NewTime - fTime;
 
     {$IFDEF DebugDisplay}
-    DebugWriteln('not getting new frame' + sLineBreak +
-        'Time:      '+inttostr(floor(Time*1000)) + sLineBreak +
-        'VideoTime: '+inttostr(floor(fTime*1000)) + sLineBreak +
-        'TimeBase:  '+inttostr(floor(fTimeBase*1000)) + sLineBreak +
-        'TimeDiff:  '+inttostr(floor(TimeDifference*1000)));
+    DebugWriteln('Time:      '+inttostr(floor(Time*1000)) + sLineBreak +
+                 'VideoTime: '+inttostr(floor(fTime*1000)) + sLineBreak +
+                 'TimeBase:  '+inttostr(floor(fTimeBase*1000)) + sLineBreak +
+                 'TimeDiff:  '+inttostr(floor(TimeDifference*1000)));
     {$endif}
 
-    // we do not need a new frame now
-    Exit;
+    // check if last time is more than one frame in the past 
+    if (TimeDifference < fTimeBase) then
+    begin
+      {$ifdef DebugFrames}
+      // frame delay debug display
+      GoldenRec.Spawn(200,15,1,16,0,-1,ColoredStar,$00ff00);
+      {$endif}
+
+      {$IFDEF DebugDisplay}
+      DebugWriteln('not getting new frame' + sLineBreak +
+          'Time:      '+inttostr(floor(Time*1000)) + sLineBreak +
+          'VideoTime: '+inttostr(floor(fTime*1000)) + sLineBreak +
+          'TimeBase:  '+inttostr(floor(fTimeBase*1000)) + sLineBreak +
+          'TimeDiff:  '+inttostr(floor(TimeDifference*1000)));
+      {$endif}
+
+      // we do not need a new frame now
+      Exit;
+    end;
   end;
 
-  // update video-time to the next frame
-  fTime := fTime + fTimeBase;
-  TimeDifference := myTime - fTime;
+  {$IFDEF VideoBenchmark}
+  Log.BenchmarkStart(15);
+  {$ENDIF}
+  
+  // fetch new frame (updates fTime)
+  Success := DecodeFrame();
+  TimeDifference := NewTime - fTime;
 
   // check if we have to skip frames
   if (TimeDifference >= FRAME_DROPCOUNT*fTimeBase) then
@@ -640,19 +668,18 @@ begin
 
     // skip half of the frames, this is much smoother than to skip all at once
     for i := 1 to DropFrameCount (*div 2*) do
-      DecodeFrame(AVPacket, pts);
+      Success := DecodeFrame();
   end;
 
-  {$IFDEF VideoBenchmark}
-  Log.BenchmarkStart(15);
-  {$ENDIF}
-
-  if (not DecodeFrame(AVPacket, pts)) then
+  // check if we got an EOF or error 
+  if (not Success) then
   begin
     if fLoop then
     begin
-      // Record the time we looped. This is used to keep the loops in time. otherwise they speed
+      // we have to loop, so rewind
       SetPosition(0);
+      // record the start-time of the current loop, so we can
+      // determine the position in the stream (fTime-fLoopTime) later.
       fLoopTime := Time;
     end;
     Exit;
@@ -695,6 +722,9 @@ begin
       fCodecContext^.width, fCodecContext^.height,
       PIXEL_FMT_OPENGL, GL_UNSIGNED_BYTE, fAVFrameRGB^.data[0]);
 
+  if (not fFrameTexValid) then
+    fFrameTexValid := true;
+
   {$ifdef DebugFrames}
   //frame decode debug display
   GoldenRec.Spawn(200, 35, 1, 16, 0, -1, ColoredStar, $ffff00);
@@ -738,7 +768,9 @@ begin
     acoLetterBox: begin
       ScaledVideoWidth  := RenderW;
       ScaledVideoHeight := RenderH * ScreenAspect/fAspect;
-    end;
+    end
+    else
+      raise Exception.Create('Unhandled aspect correction!');
   end;
 
   // center video
@@ -762,8 +794,18 @@ var
 begin
   // have a nice black background to draw on
   // (even if there were errors opening the vid)
-  glClearColor(0, 0, 0, 0);
-  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
+  // TODO: Philipp: IMO TVideoPlayback should not clear the screen at
+  //       all, because clearing is already done by the background class
+  //       at this moment.
+  if (Screen = 1) then
+  begin
+    // It is important that we just clear once before we start
+    // drawing the first screen otherwise the first screen
+    // would be cleared by the drawgl called when the second
+    // screen is drawn
+    glClearColor(0, 0, 0, 0);
+    glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
+  end;
 
   // exit if there's nothing to draw
   if (not fOpened) then
@@ -858,6 +900,14 @@ procedure TVideoPlayback_FFmpeg.Stop;
 begin
 end;
 
+{**
+ * Sets the stream's position.
+ * The stream is set to the first keyframe with timestamp <= Time.
+ * Note that fTime is set to Time no matter if the actual position seeked to is
+ * at Time or the time of a preceding keyframe. fTime will be updated to the
+ * actual frame time when GetFrame() is called the next time.
+ * @param Time new position in seconds
+ *}
 procedure TVideoPlayback_FFmpeg.SetPosition(Time: real);
 var
   SeekFlags: integer;
@@ -871,13 +921,18 @@ begin
   // TODO: handle fLoop-times
   //Time := Time mod VideoDuration;
 
-  // backward seeking might fail without AVSEEK_FLAG_BACKWARD
-  SeekFlags := AVSEEK_FLAG_ANY;
-  if (Time < fTime) then
-    SeekFlags := SeekFlags or AVSEEK_FLAG_BACKWARD;
+  // Do not use the AVSEEK_FLAG_ANY here. It will seek to any frame, even
+  // non keyframes (P-/B-frames). It will produce corrupted video frames as
+  // FFmpeg does not use the information of the preceding I-frame.
+  // The picture might be gray or green until the next keyframe occurs.
+  // Instead seek the first keyframe smaller than the requested time
+  // (AVSEEK_FLAG_BACKWARD). As this can be some seconds earlier than the
+  // requested time, let the sync in GetFrame() do its job.
+  SeekFlags := AVSEEK_FLAG_BACKWARD;
 
   fTime := Time;
   fEOF := false;
+  fFrameTexValid := false; 
 
   if (av_seek_frame(fFormatContext, fStreamIndex, Floor(Time/fTimeBase), SeekFlags) < 0) then
   begin
@@ -890,7 +945,6 @@ end;
 
 function  TVideoPlayback_FFmpeg.GetPosition: real;
 begin
-  // TODO: return video-position in seconds
   Result := fTime;
 end;
 
diff --git a/unicode/src/media/UVisualizer.pas b/unicode/src/media/UVisualizer.pas
index 9af6d8c2..37e0268a 100644
--- a/unicode/src/media/UVisualizer.pas
+++ b/unicode/src/media/UVisualizer.pas
@@ -484,7 +484,11 @@ begin
   glMatrixMode(GL_PROJECTION);
   glPushMatrix();
   glLoadIdentity();
-  gluOrtho2D(0, 1, 0, 1);
+  // Use count of screens instead of 1 for the right corner
+  // otherwise we would draw the visualization streched over both screens
+  // another point is that we draw over the at this time drawn first
+  // screen, if Screen = 2
+  gluOrtho2D(0, Screens, 0, 1);
   glMatrixMode(GL_MODELVIEW);
   glPushMatrix();
   glLoadIdentity();
@@ -496,11 +500,12 @@ begin
   glColor4f(1, 1, 1, 1);
 
   // draw projectM frame
+  // Screen is 1 to 2. So current screen is from (Screen - 1) to (Screen)
   glBegin(GL_QUADS);
-    glTexCoord2f(0, 0); glVertex2f(0, 0);
-    glTexCoord2f(1, 0); glVertex2f(1, 0);
-    glTexCoord2f(1, 1); glVertex2f(1, 1);
-    glTexCoord2f(0, 1); glVertex2f(0, 1);
+    glTexCoord2f(0, 0); glVertex2f((Screen - 1), 0);
+    glTexCoord2f(1, 0); glVertex2f(Screen, 0);
+    glTexCoord2f(1, 1); glVertex2f(Screen, 1);
+    glTexCoord2f(0, 1); glVertex2f((Screen - 1), 1);
   glEnd();
 
   glDisable(GL_TEXTURE_2D);