Moved: The folder classes has been renamed to base

Updated: ultrastardx.dpr has been changed accordingly 

git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@1339 b956fd51-792f-4845-bead-9b4dfca2ff2c

1 files changed, 0 insertions, 1132 deletions

diff --git a/src/classes/UAudioPlayback_SoftMixer.pas b/src/classes/UAudioPlayback_SoftMixer.pas
deleted file mode 100644
index 6ddae980..00000000
--- a/src/classes/UAudioPlayback_SoftMixer.pas
+++ /dev/null
@@ -1,1132 +0,0 @@
-unit UAudioPlayback_SoftMixer;
-
-interface
-
-{$IFDEF FPC}
-  {$MODE Delphi}
-{$ENDIF}
-
-{$I switches.inc}
-
-
-uses
-  Classes,
-  SysUtils,
-  sdl,
-  URingBuffer,
-  UMusic,
-  UAudioPlaybackBase;
-
-type
-  TAudioPlayback_SoftMixer = class;
-
-  TGenericPlaybackStream = class(TAudioPlaybackStream)
-    private
-      Engine: TAudioPlayback_SoftMixer;
-
-      SampleBuffer:      PChar;
-      SampleBufferSize:  integer;
-      SampleBufferCount: integer; // number of available bytes in SampleBuffer
-      SampleBufferPos:   cardinal;
-
-      SourceBuffer:      PChar;
-      SourceBufferSize:  integer;
-      SourceBufferCount: integer; // number of available bytes in SourceBuffer
-
-      Converter: TAudioConverter;
-      Status:   TStreamStatus;
-      InternalLock: PSDL_Mutex;
-      SoundEffects: TList;
-      fVolume: single;
-
-      FadeInStartTime, FadeInTime: cardinal;
-      FadeInStartVolume, FadeInTargetVolume: single;
-
-      NeedsRewind: boolean;
-
-      procedure Reset();
-
-      procedure ApplySoundEffects(Buffer: PChar; BufferSize: integer);
-      function InitFormatConversion(): boolean;
-      procedure FlushBuffers();
-
-      procedure LockSampleBuffer(); {$IFDEF HasInline}inline;{$ENDIF}
-      procedure UnlockSampleBuffer(); {$IFDEF HasInline}inline;{$ENDIF}
-    protected
-      function GetLatency(): double;        override;
-      function GetStatus(): TStreamStatus;  override;
-      function GetVolume(): single;         override;
-      procedure SetVolume(Volume: single);  override;
-      function GetLength(): real;           override;
-      function GetLoop(): boolean;          override;
-      procedure SetLoop(Enabled: boolean);  override;
-      function GetPosition: real;           override;
-      procedure SetPosition(Time: real);    override;
-    public
-      constructor Create(Engine: TAudioPlayback_SoftMixer);
-      destructor Destroy(); override;
-
-      function Open(SourceStream: TAudioSourceStream): boolean; override;
-      procedure Close();                    override;
-
-      procedure Play();                     override;
-      procedure Pause();                    override;
-      procedure Stop();                     override;
-      procedure FadeIn(Time: real; TargetVolume: single); override;
-
-      function GetAudioFormatInfo(): TAudioFormatInfo; override;
-
-      function ReadData(Buffer: PChar; BufferSize: integer): integer;
-
-      function GetPCMData(var Data: TPCMData): Cardinal; override;
-      procedure GetFFTData(var Data: TFFTData);          override;
-
-      procedure AddSoundEffect(Effect: TSoundEffect);    override;
-      procedure RemoveSoundEffect(Effect: TSoundEffect); override;
-  end;
-
-  TAudioMixerStream = class
-    private
-      Engine: TAudioPlayback_SoftMixer;
-
-      ActiveStreams: TList;
-      MixerBuffer: PChar;
-      InternalLock: PSDL_Mutex;
-
-      AppVolume: single;
-
-      procedure Lock(); {$IFDEF HasInline}inline;{$ENDIF}
-      procedure Unlock(); {$IFDEF HasInline}inline;{$ENDIF}
-
-      function GetVolume(): single;
-      procedure SetVolume(Volume: single);
-    public
-      constructor Create(Engine: TAudioPlayback_SoftMixer);
-      destructor Destroy(); override;
-      procedure AddStream(Stream: TAudioPlaybackStream);
-      procedure RemoveStream(Stream: TAudioPlaybackStream);
-      function ReadData(Buffer: PChar; BufferSize: integer): integer;
-
-      property Volume: single read GetVolume write SetVolume;
-  end;
-
-  TAudioPlayback_SoftMixer = class(TAudioPlaybackBase)
-    private
-      MixerStream: TAudioMixerStream;
-    protected
-      FormatInfo: TAudioFormatInfo;
-
-      function InitializeAudioPlaybackEngine(): boolean; virtual; abstract;
-      function StartAudioPlaybackEngine(): boolean;      virtual; abstract;
-      procedure StopAudioPlaybackEngine();               virtual; abstract;
-      function FinalizeAudioPlaybackEngine(): boolean;   virtual; abstract;
-      procedure AudioCallback(Buffer: PChar; Size: integer); {$IFDEF HasInline}inline;{$ENDIF}
-
-      function CreatePlaybackStream(): TAudioPlaybackStream; override;
-    public
-      function GetName: String; override; abstract;
-      function InitializePlayback(): boolean; override;
-      function FinalizePlayback: boolean; override;
-
-      procedure SetAppVolume(Volume: single); override;
-
-      function CreateVoiceStream(ChannelMap: integer; FormatInfo: TAudioFormatInfo): TAudioVoiceStream; override;
-
-      function GetMixer(): TAudioMixerStream; {$IFDEF HasInline}inline;{$ENDIF}
-      function GetAudioFormatInfo(): TAudioFormatInfo;
-
-      procedure MixBuffers(DstBuffer, SrcBuffer: PChar; Size: Cardinal; Volume: Single); virtual;
-  end;
-
-type
-  TGenericVoiceStream = class(TAudioVoiceStream)
-    private
-      VoiceBuffer: TRingBuffer;
-      BufferLock: PSDL_Mutex;
-      PlaybackStream: TGenericPlaybackStream;
-      Engine: TAudioPlayback_SoftMixer;
-    public
-      constructor Create(Engine: TAudioPlayback_SoftMixer);
-
-      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;
-      function IsEOF(): boolean; override;
-      function IsError(): boolean; override;
-  end;
-
-const
-  SOURCE_BUFFER_FRAMES = 4096;
-
-const
-  MAX_VOICE_DELAY = 0.500; // 20ms
-
-implementation
-
-uses
-  Math,
-  ULog,
-  UIni,
-  UFFT,
-  UAudioConverter,
-  UMain;
-
-{ TAudioMixerStream }
-
-constructor TAudioMixerStream.Create(Engine: TAudioPlayback_SoftMixer);
-begin
-  inherited Create();
-
-  Self.Engine := Engine;
-
-  ActiveStreams := TList.Create;
-  InternalLock := SDL_CreateMutex();
-  AppVolume := 1.0;
-end;
-
-destructor TAudioMixerStream.Destroy();
-begin
-  if assigned(MixerBuffer) then
-    Freemem(MixerBuffer);
-  ActiveStreams.Free;
-  SDL_DestroyMutex(InternalLock);
-  inherited;
-end;
-
-procedure TAudioMixerStream.Lock();
-begin
-  SDL_mutexP(InternalLock);
-end;
-
-procedure TAudioMixerStream.Unlock();
-begin
-  SDL_mutexV(InternalLock);
-end;
-
-function TAudioMixerStream.GetVolume(): single;
-begin
-  Lock();
-  Result := AppVolume;
-  Unlock();
-end;
-
-procedure TAudioMixerStream.SetVolume(Volume: single);
-begin
-  Lock();
-  AppVolume := Volume;
-  Unlock();
-end;
-
-procedure TAudioMixerStream.AddStream(Stream: TAudioPlaybackStream);
-begin
-  if not assigned(Stream) then
-    Exit;
-
-  Lock();
-  // check if stream is already in list to avoid duplicates
-  if (ActiveStreams.IndexOf(Pointer(Stream)) = -1) then
-    ActiveStreams.Add(Pointer(Stream));
-  Unlock();
-end;
-
-(*
- * Sets the entry of stream in the ActiveStreams-List to nil
- * but does not remove it from the list (Count is not changed!).
- * Otherwise iterations over the elements might fail due to a
- * changed Count-property.
- * Call ActiveStreams.Pack() to remove the nil-pointers
- * or check for nil-pointers when accessing ActiveStreams.
- *)
-procedure TAudioMixerStream.RemoveStream(Stream: TAudioPlaybackStream);
-var
-  Index: integer;
-begin
-  Lock();
-  Index := activeStreams.IndexOf(Pointer(Stream));
-  if (Index <> -1) then
-  begin
-    // remove entry but do not decrease count-property
-    ActiveStreams[Index] := nil;
-  end;
-  Unlock();
-end;
-
-function TAudioMixerStream.ReadData(Buffer: PChar; BufferSize: integer): integer;
-var
-  i: integer;
-  Size: integer;
-  Stream: TGenericPlaybackStream;
-  NeedsPacking: boolean;
-begin
-  Result := BufferSize;
-
-  // zero target-buffer (silence)
-  FillChar(Buffer^, BufferSize, 0);
-
-  // resize mixer-buffer if necessary
-  ReallocMem(MixerBuffer, BufferSize);
-  if not assigned(MixerBuffer) then
-    Exit;
-
-  Lock();
-
-  NeedsPacking := false;
-
-  // mix streams to one stream
-  for i := 0 to ActiveStreams.Count-1 do
-  begin
-    if (ActiveStreams[i] = nil) then
-    begin
-      NeedsPacking := true;
-      continue;
-    end;
-
-    Stream := TGenericPlaybackStream(ActiveStreams[i]);
-    // fetch data from current stream
-    Size := Stream.ReadData(MixerBuffer, BufferSize);
-    if (Size > 0) then
-    begin
-      // mix stream-data with mixer-buffer
-      // Note: use Self.appVolume instead of Self.Volume to prevent recursive locking
-      Engine.MixBuffers(Buffer, MixerBuffer, Size, AppVolume * Stream.Volume);
-    end;
-  end;
-
-  // remove nil-pointers from list
-  if (NeedsPacking) then
-  begin
-    ActiveStreams.Pack();
-  end;
-
-  Unlock();
-end;
-
-
-{ TGenericPlaybackStream }
-
-constructor TGenericPlaybackStream.Create(Engine: TAudioPlayback_SoftMixer);
-begin
-  inherited Create();
-  Self.Engine := Engine;
-  InternalLock := SDL_CreateMutex();
-  SoundEffects := TList.Create;
-  Status := ssStopped;
-  Reset();
-end;
-
-destructor TGenericPlaybackStream.Destroy();
-begin
-  Close();
-  SDL_DestroyMutex(InternalLock);
-  FreeAndNil(SoundEffects);
-  inherited;
-end;
-
-procedure TGenericPlaybackStream.Reset();
-begin
-  SourceStream := nil;
-
-  FreeAndNil(Converter);
-
-  FreeMem(SampleBuffer);
-  SampleBuffer := nil;
-  SampleBufferPos := 0;
-  SampleBufferSize := 0;
-  SampleBufferCount := 0;
-
-  FreeMem(SourceBuffer);
-  SourceBuffer := nil;
-  SourceBufferSize := 0;
-  SourceBufferCount := 0;
-
-  NeedsRewind := false;
-
-  fVolume := 0;
-  SoundEffects.Clear;
-  FadeInTime := 0;
-end;
-
-function TGenericPlaybackStream.Open(SourceStream: TAudioSourceStream): boolean;
-begin
-  Result := false;
-
-  Close();
-
-  if (not assigned(SourceStream)) then
-    Exit;
-  Self.SourceStream := SourceStream;
-
-  if (not InitFormatConversion()) then
-  begin
-    // reset decode-stream so it will not be freed on destruction
-    Self.SourceStream := nil;
-    Exit;
-  end;
-
-  SourceBufferSize := SOURCE_BUFFER_FRAMES * SourceStream.GetAudioFormatInfo().FrameSize;
-  GetMem(SourceBuffer, SourceBufferSize);
-  fVolume := 1.0;
-
-  Result := true;
-end;
-
-procedure TGenericPlaybackStream.Close();
-begin
-  // stop audio-callback on this stream
-  Stop();
-
-  // Note: PerformOnClose must be called before SourceStream is invalidated
-  PerformOnClose();
-  // and free data
-  Reset();
-end;
-
-procedure TGenericPlaybackStream.LockSampleBuffer();
-begin
-  SDL_mutexP(InternalLock);
-end;
-
-procedure TGenericPlaybackStream.UnlockSampleBuffer();
-begin
-  SDL_mutexV(InternalLock);
-end;
-
-function TGenericPlaybackStream.InitFormatConversion(): boolean;
-var
-  SrcFormatInfo: TAudioFormatInfo;
-  DstFormatInfo: TAudioFormatInfo;
-begin
-  Result := false;
-
-  SrcFormatInfo := SourceStream.GetAudioFormatInfo();
-  DstFormatInfo := GetAudioFormatInfo();
-
-  // TODO: selection should not be done here, use a factory (TAudioConverterFactory) instead 
-  {$IF Defined(UseFFmpegResample)}
-  Converter := TAudioConverter_FFmpeg.Create();
-  {$ELSEIF Defined(UseSRCResample)}
-  Converter := TAudioConverter_SRC.Create();
-  {$ELSE}
-  Converter := TAudioConverter_SDL.Create();
-  {$IFEND}
-
-  Result := Converter.Init(SrcFormatInfo, DstFormatInfo);
-end;
-
-procedure TGenericPlaybackStream.Play();
-var
-  Mixer: TAudioMixerStream;
-begin
-  // only paused streams are not flushed
-  if (Status = ssPaused) then
-    NeedsRewind := false;
-
-  // rewind if necessary. Cases that require no rewind are:
-  // - stream was created and never played
-  // - stream was paused and is resumed now
-  // - stream was stopped and set to a new position already
-  if (NeedsRewind) then
-    SetPosition(0);
-
-  // update status
-  Status := ssPlaying;
-
-  NeedsRewind := true;
-
-  // add this stream to the mixer
-  Mixer := Engine.GetMixer();
-  if (Mixer <> nil) then
-    Mixer.AddStream(Self);
-end;
-
-procedure TGenericPlaybackStream.FadeIn(Time: real; TargetVolume: single);
-begin
-  FadeInTime := Trunc(Time * 1000);
-  FadeInStartTime := SDL_GetTicks();
-  FadeInStartVolume := fVolume;
-  FadeInTargetVolume := TargetVolume;
-  Play();
-end;
-
-procedure TGenericPlaybackStream.Pause();
-var
-  Mixer: TAudioMixerStream;
-begin
-  if (Status <> ssPlaying) then
-    Exit;
-
-  Status := ssPaused;
-
-  Mixer := Engine.GetMixer();
-  if (Mixer <> nil) then
-    Mixer.RemoveStream(Self);
-end;
-
-procedure TGenericPlaybackStream.Stop();
-var
-  Mixer: TAudioMixerStream;
-begin
-  if (Status = ssStopped) then
-    Exit;
-
-  Status := ssStopped;
-
-  Mixer := Engine.GetMixer();
-  if (Mixer <> nil) then
-    Mixer.RemoveStream(Self);
-end;
-
-function TGenericPlaybackStream.GetLoop(): boolean;
-begin
-  if assigned(SourceStream) then
-    Result := SourceStream.Loop
-  else
-    Result := false;
-end;
-
-procedure TGenericPlaybackStream.SetLoop(Enabled: boolean);
-begin
-  if assigned(SourceStream) then
-    SourceStream.Loop := Enabled;
-end;
-
-function TGenericPlaybackStream.GetLength(): real;
-begin
-  if assigned(SourceStream) then
-    Result := SourceStream.Length
-  else
-    Result := -1;
-end;
-
-function TGenericPlaybackStream.GetLatency(): double;
-begin
-  Result := Engine.GetLatency();
-end;
-
-function TGenericPlaybackStream.GetStatus(): TStreamStatus;
-begin
-  Result := Status;
-end;
-
-function TGenericPlaybackStream.GetAudioFormatInfo(): TAudioFormatInfo;
-begin
-  Result := Engine.GetAudioFormatInfo();
-end;
-
-procedure TGenericPlaybackStream.FlushBuffers();
-begin
-  SampleBufferCount := 0;
-  SampleBufferPos := 0;
-  SourceBufferCount := 0;
-end;
-
-procedure TGenericPlaybackStream.ApplySoundEffects(Buffer: PChar; BufferSize: integer);
-var
-  i: integer;
-begin
-  for i := 0 to SoundEffects.Count-1 do
-  begin
-    if (SoundEffects[i] <> nil) then
-    begin
-      TSoundEffect(SoundEffects[i]).Callback(Buffer, BufferSize);
-    end;
-  end;
-end;
-
-function TGenericPlaybackStream.ReadData(Buffer: PChar; BufferSize: integer): integer;
-var
-  ConversionInputCount: integer;
-  ConversionOutputSize: integer;   // max. number of converted data (= buffer size)
-  ConversionOutputCount: integer;  // actual number of converted data
-  SourceSize: integer;
-  RequestedSourceSize: integer;
-  NeededSampleBufferSize: integer;
-  BytesNeeded, BytesAvail: integer;
-  SourceFormatInfo, OutputFormatInfo: TAudioFormatInfo;
-  SourceFrameSize, OutputFrameSize: integer;
-  SkipOutputCount: integer;  // number of output-data bytes to skip
-  SkipSourceCount: integer;  // number of source-data bytes to skip
-  FillCount: integer;  // number of bytes to fill with padding data
-  CopyCount: integer;
-  PadFrame: PChar;
-  i: integer;
-begin
-  Result := -1;
-
-  // sanity check for the source-stream
-  if (not assigned(SourceStream)) then
-    Exit;
-  
-  SkipOutputCount := 0;
-  SkipSourceCount := 0;
-  FillCount := 0;
-
-  SourceFormatInfo := SourceStream.GetAudioFormatInfo();
-  SourceFrameSize := SourceFormatInfo.FrameSize;
-  OutputFormatInfo := GetAudioFormatInfo();
-  OutputFrameSize := OutputFormatInfo.FrameSize;
-
-  // synchronize (adjust buffer size)
-  BytesNeeded := Synchronize(BufferSize, OutputFormatInfo);
-  if (BytesNeeded > BufferSize) then
-  begin
-    SkipOutputCount := BytesNeeded - BufferSize;
-    BytesNeeded := BufferSize;
-  end
-  else if (BytesNeeded < BufferSize) then
-  begin
-    FillCount := BufferSize - BytesNeeded;
-  end;
-
-  // lock access to sample-buffer
-  LockSampleBuffer();
-  try
-
-    // skip sample-buffer data
-    SampleBufferPos := SampleBufferPos + SkipOutputCount;
-    // size of available bytes in SampleBuffer after skipping
-    SampleBufferCount := SampleBufferCount - SampleBufferPos;
-    // update byte skip-count
-    SkipOutputCount := -SampleBufferCount;
-
-    // now that we skipped all buffered data from the last pass, we have to skip
-    // data directly after fetching it from the source-stream.
-    if (SkipOutputCount > 0) then
-    begin
-      SampleBufferCount := 0;
-      // convert skip-count to source-format units and resize to a multiple of
-      // the source frame-size.
-      SkipSourceCount := Round((SkipOutputCount * OutputFormatInfo.GetRatio(SourceFormatInfo)) /
-                               SourceFrameSize) * SourceFrameSize;
-      SkipOutputCount := 0;
-    end;
-
-    // copy data to front of buffer
-    if ((SampleBufferCount > 0) and (SampleBufferPos > 0)) then
-      Move(SampleBuffer[SampleBufferPos], SampleBuffer[0], SampleBufferCount);
-    SampleBufferPos := 0;
-
-    // resize buffer to a reasonable size
-    if (BufferSize > SampleBufferCount) then
-    begin
-      // Note: use BufferSize instead of BytesNeeded to minimize the need for resizing
-      SampleBufferSize := BufferSize;
-      ReallocMem(SampleBuffer, SampleBufferSize);
-      if (not assigned(SampleBuffer)) then
-        Exit;
-    end;
-
-    // fill sample-buffer (fetch and convert one block of source data per loop)
-    while (SampleBufferCount < BytesNeeded) do
-    begin
-      // move remaining source data from the previous pass to front of buffer
-      if (SourceBufferCount > 0) then
-      begin
-        Move(SourceBuffer[SourceBufferSize-SourceBufferCount],
-             SourceBuffer[0],
-             SourceBufferCount);
-      end;
-
-      SourceSize := SourceStream.ReadData(
-          @SourceBuffer[SourceBufferCount], SourceBufferSize-SourceBufferCount);
-      // break on error (-1) or if no data is available (0), e.g. while seeking
-      if (SourceSize <= 0) then
-      begin
-        // if we do not have data -> exit
-        if (SourceBufferCount = 0) then
-        begin
-          FlushBuffers();
-          Exit;
-        end;
-        // if we have some data, stop retrieving data from the source stream
-        // and use the data we have so far
-        Break;
-      end;
-
-      SourceBufferCount := SourceBufferCount + SourceSize;
-
-      // end-of-file reached -> stop playback
-      if (SourceStream.EOF) then
-      begin
-        if (Loop) then
-          SourceStream.Position := 0
-        else
-          Stop();
-      end;
-
-      if (SkipSourceCount > 0) then
-      begin
-        // skip data and update source buffer count
-        SourceBufferCount := SourceBufferCount - SkipSourceCount;
-        SkipSourceCount := -SourceBufferCount;
-        // continue with next pass if we skipped all data
-        if (SourceBufferCount <= 0) then
-        begin
-          SourceBufferCount := 0;
-          Continue;
-        end;
-      end;
-
-      // calc buffer size (might be bigger than actual resampled byte count)
-      ConversionOutputSize := Converter.GetOutputBufferSize(SourceBufferCount);
-      NeededSampleBufferSize := SampleBufferCount + ConversionOutputSize;
-
-      // resize buffer if necessary
-      if (SampleBufferSize < NeededSampleBufferSize) then
-      begin
-        SampleBufferSize := NeededSampleBufferSize;
-        ReallocMem(SampleBuffer, SampleBufferSize);
-        if (not assigned(SampleBuffer)) then
-        begin
-          FlushBuffers();
-          Exit;
-        end;
-      end;
-
-      // resample source data (Note: ConversionInputCount might be adjusted by Convert())
-      ConversionInputCount := SourceBufferCount;
-      ConversionOutputCount := Converter.Convert(
-          SourceBuffer, @SampleBuffer[SampleBufferCount], ConversionInputCount);
-      if (ConversionOutputCount = -1) then
-      begin
-        FlushBuffers();
-        Exit;
-      end;
-
-      // adjust sample- and source-buffer count by the number of converted bytes
-      SampleBufferCount := SampleBufferCount + ConversionOutputCount;
-      SourceBufferCount := SourceBufferCount - ConversionInputCount;
-    end;
-
-    // apply effects
-    ApplySoundEffects(SampleBuffer, SampleBufferCount);
-
-    // copy data to result buffer
-    CopyCount := Min(BytesNeeded, SampleBufferCount);
-    Move(SampleBuffer[0], Buffer[BufferSize - BytesNeeded], CopyCount);
-    Dec(BytesNeeded, CopyCount);
-    SampleBufferPos := CopyCount;
-
-  // release buffer lock
-  finally
-    UnlockSampleBuffer();
-  end;
-
-  // pad the buffer with the last frame if we are to fast
-  if (FillCount > 0) then
-  begin
-    if (CopyCount >= OutputFrameSize) then
-      PadFrame := @Buffer[CopyCount-OutputFrameSize]
-    else
-      PadFrame := nil;
-    FillBufferWithFrame(@Buffer[CopyCount], FillCount,
-                        PadFrame, OutputFrameSize);
-  end;
-
-  // BytesNeeded now contains the number of remaining bytes we were not able to fetch
-  Result := BufferSize - BytesNeeded;
-end;
-
-function TGenericPlaybackStream.GetPCMData(var Data: TPCMData): Cardinal;
-var
-  ByteCount: integer;
-begin
-  Result := 0;
-
-  // just SInt16 stereo support for now
-  if ((Engine.GetAudioFormatInfo().Format <> asfS16) or
-      (Engine.GetAudioFormatInfo().Channels <> 2)) then
-  begin
-    Exit;
-  end;
-
-  // zero memory
-  FillChar(Data, SizeOf(Data), 0);
-
-  // TODO: At the moment just the first samples of the SampleBuffer
-  // are returned, even if there is newer data in the upper samples.
-
-  LockSampleBuffer();
-  ByteCount := Min(SizeOf(Data), SampleBufferCount);
-  if (ByteCount > 0) then
-  begin
-    Move(SampleBuffer[0], Data, ByteCount);
-  end;
-  UnlockSampleBuffer();
-  
-  Result := ByteCount div SizeOf(TPCMStereoSample);
-end;
-
-procedure TGenericPlaybackStream.GetFFTData(var Data: TFFTData);
-var
-  i: integer;
-  Frames: integer;
-  DataIn: PSingleArray;
-  AudioFormat: TAudioFormatInfo;
-begin
-  // only works with SInt16 and Float values at the moment
-  AudioFormat := GetAudioFormatInfo();
-
-  DataIn := AllocMem(FFTSize * SizeOf(Single));
-  if (DataIn = nil) then
-    Exit;
-
-  LockSampleBuffer();
-  // TODO: We just use the first Frames frames, the others are ignored.
-  Frames := Min(FFTSize, SampleBufferCount div AudioFormat.FrameSize);
-  // use only first channel and convert data to float-values
-  case AudioFormat.Format of
-    asfS16:
-    begin
-      for i := 0 to Frames-1 do
-        DataIn[i] := PSmallInt(@SampleBuffer[i*AudioFormat.FrameSize])^ / -Low(SmallInt);
-    end;
-    asfFloat:
-    begin
-      for i := 0 to Frames-1 do
-        DataIn[i] := PSingle(@SampleBuffer[i*AudioFormat.FrameSize])^;
-    end;
-  end;
-  UnlockSampleBuffer();
-
-  WindowFunc(fwfHanning, FFTSize, DataIn);
-  PowerSpectrum(FFTSize, DataIn, @Data);
-  FreeMem(DataIn);
-
-  // resize data to a 0..1 range
-  for i := 0 to High(TFFTData) do
-  begin
-    Data[i] := Sqrt(Data[i]) / 100;
-  end;
-end;
-
-procedure TGenericPlaybackStream.AddSoundEffect(Effect: TSoundEffect);
-begin
-  if (not assigned(Effect)) then
-    Exit;
-
-  LockSampleBuffer();
-  // check if effect is already in list to avoid duplicates
-  if (SoundEffects.IndexOf(Pointer(Effect)) = -1) then
-    SoundEffects.Add(Pointer(Effect));
-  UnlockSampleBuffer();
-end;
-
-procedure TGenericPlaybackStream.RemoveSoundEffect(Effect: TSoundEffect);
-begin
-  LockSampleBuffer();
-  SoundEffects.Remove(Effect);
-  UnlockSampleBuffer();
-end;
-
-function TGenericPlaybackStream.GetPosition: real;
-var
-  BufferedTime: double;
-begin
-  if assigned(SourceStream) then
-  begin
-    LockSampleBuffer();
-
-    // calc the time of source data that is buffered (in the SampleBuffer and SourceBuffer)
-    // but not yet outputed
-    BufferedTime := (SampleBufferCount - SampleBufferPos) / Engine.FormatInfo.BytesPerSec +
-                    SourceBufferCount / SourceStream.GetAudioFormatInfo().BytesPerSec;
-    // and subtract it from the source position
-    Result := SourceStream.Position - BufferedTime;
-
-    UnlockSampleBuffer();
-  end
-  else
-  begin
-    Result := -1;
-  end;
-end;
-
-procedure TGenericPlaybackStream.SetPosition(Time: real);
-begin
-  if assigned(SourceStream) then
-  begin
-    LockSampleBuffer();
-
-    SourceStream.Position := Time;
-    if (Status = ssStopped) then
-      NeedsRewind := false;
-    // do not use outdated data
-    FlushBuffers();
-
-    AvgSyncDiff := -1;
-    
-    UnlockSampleBuffer();
-  end;
-end;
-
-function TGenericPlaybackStream.GetVolume(): single;
-var
-  FadeAmount: Single;
-begin
-  LockSampleBuffer();
-  // adjust volume if fading is enabled
-  if (FadeInTime > 0) then
-  begin
-    FadeAmount := (SDL_GetTicks() - FadeInStartTime) / FadeInTime;
-    // check if fade-target is reached
-    if (FadeAmount >= 1) then
-    begin
-      // target reached -> stop fading
-      FadeInTime := 0;
-      fVolume := FadeInTargetVolume;
-    end
-    else
-    begin
-      // fading in progress
-      fVolume := FadeAmount*FadeInTargetVolume + (1-FadeAmount)*FadeInStartVolume;
-    end;
-  end;
-  // return current volume
-  Result := fVolume;
-  UnlockSampleBuffer();
-end;
-
-procedure TGenericPlaybackStream.SetVolume(Volume: single);
-begin
-  LockSampleBuffer();
-  // stop fading
-  FadeInTime := 0;
-  // clamp volume
-  if (Volume > 1.0) then
-    fVolume := 1.0
-  else if (Volume < 0) then
-    fVolume := 0
-  else
-    fVolume := Volume;
-  UnlockSampleBuffer();
-end;
-
-
-{ TGenericVoiceStream }
-
-constructor TGenericVoiceStream.Create(Engine: TAudioPlayback_SoftMixer);
-begin
-  inherited Create();
-  Self.Engine := Engine;
-end;
-
-function TGenericVoiceStream.Open(ChannelMap: integer; FormatInfo: TAudioFormatInfo): boolean;
-var
-  BufferSize: integer;
-begin
-  Result := false;
-
-  Close();
-
-  if (not inherited Open(ChannelMap, FormatInfo)) then
-    Exit;
-
-  // Note:
-  // - use Self.FormatInfo instead of FormatInfo as the latter one might have a
-  //   channel size of 2.
-  // - the buffer-size must be a multiple of the FrameSize
-  BufferSize := (Ceil(MAX_VOICE_DELAY * Self.FormatInfo.BytesPerSec) div Self.FormatInfo.FrameSize) *
-                Self.FormatInfo.FrameSize;
-  VoiceBuffer := TRingBuffer.Create(BufferSize);
-
-  BufferLock := SDL_CreateMutex();
-
-
-  // create a matching playback stream for the voice-stream
-  PlaybackStream := TGenericPlaybackStream.Create(Engine);
-  // link voice- and playback-stream
-  if (not PlaybackStream.Open(Self)) then
-  begin
-    PlaybackStream.Free;
-    Exit;
-  end;
-
-  // start voice passthrough
-  PlaybackStream.Play();
-
-  Result := true;
-end;
-
-procedure TGenericVoiceStream.Close();
-begin
-  // stop and free the playback stream
-  FreeAndNil(PlaybackStream);
-
-  // free data
-  FreeAndNil(VoiceBuffer);
-  if (BufferLock <> nil) then
-    SDL_DestroyMutex(BufferLock);
-
-  inherited Close();
-end;
-
-procedure TGenericVoiceStream.WriteData(Buffer: PChar; BufferSize: integer);
-begin
-  // lock access to buffer
-  SDL_mutexP(BufferLock);
-  try
-    if (VoiceBuffer = nil) then
-      Exit;
-    VoiceBuffer.Write(Buffer, BufferSize);
-  finally
-    SDL_mutexV(BufferLock);
-  end;
-end;
-
-function TGenericVoiceStream.ReadData(Buffer: PChar; BufferSize: integer): integer;
-begin
-  Result := -1;
-
-  // lock access to buffer
-  SDL_mutexP(BufferLock);
-  try
-    if (VoiceBuffer = nil) then
-      Exit;
-    Result := VoiceBuffer.Read(Buffer, BufferSize);
-  finally
-    SDL_mutexV(BufferLock);
-  end;
-end;
-
-function TGenericVoiceStream.IsEOF(): boolean;
-begin
-  SDL_mutexP(BufferLock);
-  Result := (VoiceBuffer = nil);
-  SDL_mutexV(BufferLock);
-end;
-
-function TGenericVoiceStream.IsError(): boolean;
-begin
-  Result := false;
-end;
-
-
-{ TAudioPlayback_SoftMixer }
-
-function TAudioPlayback_SoftMixer.InitializePlayback: boolean;
-begin
-  Result := false;
-
-  //Log.LogStatus('InitializePlayback', 'UAudioPlayback_SoftMixer');
-
-  if(not InitializeAudioPlaybackEngine()) then
-    Exit;
-
-  MixerStream := TAudioMixerStream.Create(Self);
-
-  if(not StartAudioPlaybackEngine()) then
-    Exit;
-
-  Result := true;
-end;
-
-function TAudioPlayback_SoftMixer.FinalizePlayback: boolean;
-begin
-  Close;
-  StopAudioPlaybackEngine();
-
-  FreeAndNil(MixerStream);
-  FreeAndNil(FormatInfo);
-
-  FinalizeAudioPlaybackEngine();
-  inherited FinalizePlayback;
-  Result := true;
-end;
-
-procedure TAudioPlayback_SoftMixer.AudioCallback(Buffer: PChar; Size: integer);
-begin
-  MixerStream.ReadData(Buffer, Size);
-end;
-
-function TAudioPlayback_SoftMixer.GetMixer(): TAudioMixerStream;
-begin
-  Result := MixerStream;
-end;
-
-function TAudioPlayback_SoftMixer.GetAudioFormatInfo(): TAudioFormatInfo;
-begin
-  Result := FormatInfo;
-end;
-
-function TAudioPlayback_SoftMixer.CreatePlaybackStream(): TAudioPlaybackStream;
-begin
-  Result := TGenericPlaybackStream.Create(Self);
-end;
-
-function TAudioPlayback_SoftMixer.CreateVoiceStream(ChannelMap: integer; FormatInfo: TAudioFormatInfo): TAudioVoiceStream;
-var
-  VoiceStream: TGenericVoiceStream;
-begin
-  Result := nil;
-
-  // create a voice stream
-  VoiceStream := TGenericVoiceStream.Create(Self);
-  if (not VoiceStream.Open(ChannelMap, FormatInfo)) then
-  begin
-    VoiceStream.Free;
-    Exit;
-  end;
-
-  Result := VoiceStream;
-end;
-
-procedure TAudioPlayback_SoftMixer.SetAppVolume(Volume: single);
-begin
-  // sets volume only for this application
-  MixerStream.Volume := Volume;
-end;
-
-procedure TAudioPlayback_SoftMixer.MixBuffers(DstBuffer, SrcBuffer: PChar; Size: Cardinal; Volume: Single);
-var
-  SampleIndex: Cardinal;
-  SampleInt: Integer;
-  SampleFlt: Single;
-begin
-  SampleIndex := 0;
-  case FormatInfo.Format of
-    asfS16:
-    begin
-      while (SampleIndex < Size) do
-      begin
-        // apply volume and sum with previous mixer value
-        SampleInt := PSmallInt(@DstBuffer[SampleIndex])^ +
-                     Round(PSmallInt(@SrcBuffer[SampleIndex])^ * Volume);
-        // clip result
-        if (SampleInt > High(SmallInt)) then
-          SampleInt := High(SmallInt)
-        else if (SampleInt < Low(SmallInt)) then
-          SampleInt := Low(SmallInt);
-        // assign result
-        PSmallInt(@DstBuffer[SampleIndex])^ := SampleInt;
-        // increase index by one sample
-        Inc(SampleIndex, SizeOf(SmallInt));
-      end;
-    end;
-    asfFloat:
-    begin
-      while (SampleIndex < Size) do
-      begin
-        // apply volume and sum with previous mixer value
-        SampleFlt := PSingle(@DstBuffer[SampleIndex])^ +
-                     PSingle(@SrcBuffer[SampleIndex])^ * Volume;
-        // clip result
-        if (SampleFlt > 1.0) then
-          SampleFlt := 1.0
-        else if (SampleFlt < -1.0) then
-          SampleFlt := -1.0;
-        // assign result
-        PSingle(@DstBuffer[SampleIndex])^ := SampleFlt;
-        // increase index by one sample
-        Inc(SampleIndex, SizeOf(Single));
-      end;
-    end;
-    else
-    begin
-      Log.LogError('Incompatible format', 'TAudioMixerStream.MixAudio');
-    end;
-  end;
-end;
-
-end.