GetPCMData added for SDL/Portaudio

git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@935 b956fd51-792f-4845-bead-9b4dfca2ff2c

1 files changed, 899 insertions, 894 deletions

diff --git a/Game/Code/Classes/UAudioPlayback_SoftMixer.pas b/Game/Code/Classes/UAudioPlayback_SoftMixer.pas
index 29983778..75fddf95 100644
--- a/Game/Code/Classes/UAudioPlayback_SoftMixer.pas
+++ b/Game/Code/Classes/UAudioPlayback_SoftMixer.pas
@@ -1,894 +1,899 @@
-unit UAudioPlayback_SoftMixer;

-

-interface

-

-{$IFDEF FPC}

-  {$MODE Delphi}

-{$ENDIF}

-

-{$I switches.inc}

-

-

-uses

-  Classes,

-  SysUtils,

-  sdl,

-  UMusic;

-

-type

-  TAudioPlayback_SoftMixer = class;

-

-  TSoftMixerPlaybackStream = class(TAudioPlaybackStream)

-    private

-      Engine: TAudioPlayback_SoftMixer;

-

-      DecodeStream: TAudioDecodeStream;

-      SampleBuffer    : PChar;

-      SampleBufferCount: integer; // number of available bytes in SampleBuffer

-      SampleBufferPos : cardinal;

-      BytesAvail: integer;

-      cvt: TSDL_AudioCVT;

-

-      Status:   TStreamStatus;

-      Loop:     boolean;

-      _volume: integer;

-

-      InternalLock: PSDL_Mutex;

-

-      procedure Reset();

-

-      class function ConvertAudioFormatToSDL(fmt: TAudioSampleFormat): UInt16;

-      function InitFormatConversion(): boolean;

-

-      procedure Lock(); {$IFDEF HasInline}inline;{$ENDIF}

-      procedure Unlock(); {$IFDEF HasInline}inline;{$ENDIF}

-    public

-      constructor Create(Engine: TAudioPlayback_SoftMixer);

-      destructor Destroy(); override;

-

-      function SetDecodeStream(decodeStream: TAudioDecodeStream): boolean;

-

-      procedure Play();                     override;

-      procedure Pause();                    override;

-      procedure Stop();                     override;

-      procedure Close();                    override;

-      function GetLoop(): boolean;          override;

-      procedure SetLoop(Enabled: boolean);  override;

-      function GetLength(): real;           override;

-      function GetStatus(): TStreamStatus;  override;

-

-      function IsLoaded(): boolean;

-

-      function GetVolume(): integer;        override;

-      procedure SetVolume(Volume: integer); override;

-

-      // functions delegated to the decode stream

-      function GetPosition: real;

-      procedure SetPosition(Time: real);

-      function ReadData(Buffer: PChar; BufSize: integer): integer;

-

-      function GetPCMData(var data: TPCMData): Cardinal;

-      procedure GetFFTData(var data: TFFTData);

-  end;

-

-  TAudioMixerStream = class

-    private

-      activeStreams: TList;

-      mixerBuffer: PChar;

-      internalLock: PSDL_Mutex;

-

-      _volume: integer;

-

-      procedure Lock(); {$IFDEF HasInline}inline;{$ENDIF}

-      procedure Unlock(); {$IFDEF HasInline}inline;{$ENDIF}

-

-      function GetVolume(): integer;

-      procedure SetVolume(volume: integer);

-    public

-      constructor Create();

-      destructor Destroy(); override;

-      procedure AddStream(stream: TAudioPlaybackStream);

-      procedure RemoveStream(stream: TAudioPlaybackStream);

-      function ReadData(Buffer: PChar; BufSize: integer): integer;

-

-      property Volume: integer READ GetVolume WRITE SetVolume;

-  end;

-

-  TAudioPlayback_SoftMixer = class( TInterfacedObject, IAudioPlayback )

-    private

-      MusicStream: TSoftMixerPlaybackStream;

-      MixerStream: TAudioMixerStream;

-    protected

-      FormatInfo: TAudioFormatInfo;

-

-      function InitializeAudioPlaybackEngine(): boolean; virtual; abstract;

-      function StartAudioPlaybackEngine(): boolean;      virtual; abstract;

-      procedure StopAudioPlaybackEngine();               virtual; abstract;

-      procedure AudioCallback(buffer: PChar; size: integer); {$IFDEF HasInline}inline;{$ENDIF}

-    public

-      function  GetName: String;                         virtual; abstract;

-

-      function InitializePlayback(): boolean;

-      destructor Destroy; override;

-

-      function Load(const Filename: String): TSoftMixerPlaybackStream;

-

-      procedure SetVolume(Volume: integer);

-      procedure SetMusicVolume(Volume: integer);

-      procedure SetLoop(Enabled: boolean);

-      function Open(const Filename: string): boolean; // true if succeed

-      procedure Rewind;

-      procedure SetPosition(Time: real);

-      procedure Play;

-      procedure Pause;

-

-      procedure Stop;

-      procedure Close;

-      function Finished: boolean;

-      function Length: real;

-      function GetPosition: real;

-

-      // Equalizer

-      procedure GetFFTData(var data: TFFTData);

-

-      // Interface for Visualizer

-      function GetPCMData(var data: TPCMData): Cardinal;

-

-      function GetMixer(): TAudioMixerStream; {$IFDEF HasInline}inline;{$ENDIF}

-      function GetAudioFormatInfo(): TAudioFormatInfo;

-

-      // Sounds

-      function OpenSound(const Filename: String): TAudioPlaybackStream;

-      procedure PlaySound(stream: TAudioPlaybackStream);

-      procedure StopSound(stream: TAudioPlaybackStream);

-  end;

-

-implementation

-

-uses

-  Math,

-  //samplerate,

-  UFFT,

-  ULog,

-  UIni,

-  UMain;

-

-{ TAudioMixerStream }

-

-constructor TAudioMixerStream.Create();

-begin

-  activeStreams := TList.Create;

-  internalLock := SDL_CreateMutex();

-  _volume := 100;

-end;

-

-destructor TAudioMixerStream.Destroy();

-begin

-  if assigned(mixerBuffer) then

-    Freemem(mixerBuffer);

-  activeStreams.Free;

-  SDL_DestroyMutex(internalLock);

-end;

-

-procedure TAudioMixerStream.Lock();

-begin

-  SDL_mutexP(internalLock);

-end;

-

-procedure TAudioMixerStream.Unlock();

-begin

-  SDL_mutexV(internalLock);

-end;

-

-function TAudioMixerStream.GetVolume(): integer;

-begin

-  Lock();

-  result := _volume;

-  Unlock();

-end;

-

-procedure TAudioMixerStream.SetVolume(volume: integer);

-begin

-  Lock();

-  _volume := 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; BufSize: integer): integer;

-var

-  i: integer;

-  size: integer;

-  stream: TSoftMixerPlaybackStream;

-  appVolume: single;

-  needsPacking: boolean;

-begin

-  result := BufSize;

-

-  // zero target-buffer (silence)

-  FillChar(Buffer^, BufSize, 0);

-

-  // resize mixer-buffer if necessary

-  ReallocMem(mixerBuffer, BufSize);

-  if not assigned(mixerBuffer) then

-    Exit;

-

-  Lock();

-

-  // calc application volume

-  // use _volume instead of Volume to prevent recursive locking

-  appVolume := _volume / 100 * SDL_MIX_MAXVOLUME;

-

-  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 := TSoftMixerPlaybackStream(activeStreams[i]);

-    // fetch data from current stream

-    size := stream.ReadData(mixerBuffer, BufSize);

-    if (size > 0) then

-    begin

-      SDL_MixAudio(PUInt8(Buffer), PUInt8(mixerBuffer), size,

-        Trunc(appVolume * stream.Volume / 100));

-    end;

-  end;

-

-  // remove nil-pointers from list

-  if (needsPacking) then

-  begin

-    activeStreams.Pack();

-  end;

-

-  Unlock();

-end;

-

-

-{ TSoftMixerPlaybackStream }

-

-constructor TSoftMixerPlaybackStream.Create(Engine: TAudioPlayback_SoftMixer);

-begin

-  inherited Create();

-  Self.Engine := Engine;

-  internalLock := SDL_CreateMutex();

-  Reset();

-end;

-

-destructor TSoftMixerPlaybackStream.Destroy();

-begin

-  Close();

-  SDL_DestroyMutex(internalLock);

-  inherited Destroy();

-end;

-

-procedure TSoftMixerPlaybackStream.Reset();

-begin

-  Stop();

-  Loop := false;

-  // TODO: use DecodeStream.Unref() instead of Free();

-  FreeAndNil(DecodeStream);

-  FreeMem(SampleBuffer);

-  SampleBuffer := nil;

-  SampleBufferPos := 0;

-  BytesAvail := 0;

-  _volume := 0;

-end;

-

-procedure TSoftMixerPlaybackStream.Lock();

-begin

-  SDL_mutexP(internalLock);

-end;

-

-procedure TSoftMixerPlaybackStream.Unlock();

-begin

-  SDL_mutexV(internalLock);

-end;

-

-class function TSoftMixerPlaybackStream.ConvertAudioFormatToSDL(fmt: TAudioSampleFormat): UInt16;

-begin

-  case fmt of

-    asfU8:     Result := AUDIO_U8;

-    asfS8:     Result := AUDIO_S8;

-    asfU16LSB: Result := AUDIO_U16LSB;

-    asfS16LSB: Result := AUDIO_S16LSB;

-    asfU16MSB: Result := AUDIO_U16MSB;

-    asfS16MSB: Result := AUDIO_S16MSB;

-    asfU16:    Result := AUDIO_U16;

-    asfS16:    Result := AUDIO_S16;

-    else       Result := 0;

-  end;

-end;

-

-function TSoftMixerPlaybackStream.InitFormatConversion(): boolean;

-var

-  err: integer;

-  srcFormat: UInt16;

-  dstFormat: UInt16;

-  srcFormatInfo: TAudioFormatInfo;

-  dstFormatInfo: TAudioFormatInfo;

-begin

-  Result := false;

-

-  srcFormatInfo := DecodeStream.GetAudioFormatInfo();

-  dstFormatInfo := Engine.GetAudioFormatInfo();

-

-  srcFormat := ConvertAudioFormatToSDL(srcFormatInfo.Format);

-  dstFormat := ConvertAudioFormatToSDL(dstFormatInfo.Format);

-

-  if ((srcFormat = 0) or (dstFormat = 0)) then

-  begin

-    Log.LogError('Audio-format not supported by SDL', 'TSoftMixerPlaybackStream.InitFormatConversion');

-    Exit;

-  end;

-

-  if (SDL_BuildAudioCVT(@cvt,

-    srcFormat, srcFormatInfo.Channels, srcFormatInfo.SampleRate,

-    dstFormat, dstFormatInfo.Channels, dstFormatInfo.SampleRate) = -1) then

-  begin

-    Log.LogError(SDL_GetError(), 'TSoftMixerPlaybackStream.InitFormatConversion');

-    Exit;

-  end;

-

-  Result := true;

-end;

-

-function TSoftMixerPlaybackStream.SetDecodeStream(decodeStream: TAudioDecodeStream): boolean;

-begin

-  result := false;

-

-  Reset();

-

-  if not assigned(decodeStream) then

-    Exit;

-  Self.DecodeStream := decodeStream;

-  if not InitFormatConversion() then

-    Exit;

-

-  _volume := 100;

-

-  result := true;

-end;

-

-procedure TSoftMixerPlaybackStream.Close();

-begin

-  Reset();

-end;

-

-procedure TSoftMixerPlaybackStream.Play();

-var

-  mixer: TAudioMixerStream;

-begin

-  if (status <> ssPaused) then

-  begin

-    // rewind

-    if assigned(DecodeStream) then

-      DecodeStream.Position := 0;

-  end;

-  status := ssPlaying;

-

-  mixer := Engine.GetMixer();

-  if (mixer <> nil) then

-    mixer.AddStream(Self);

-end;

-

-procedure TSoftMixerPlaybackStream.Pause();

-var

-  mixer: TAudioMixerStream;

-begin

-  status := ssPaused;

-

-  mixer := Engine.GetMixer();

-  if (mixer <> nil) then

-    mixer.RemoveStream(Self);

-end;

-

-procedure TSoftMixerPlaybackStream.Stop();

-var

-  mixer: TAudioMixerStream;

-begin

-  status := ssStopped;

-

-  mixer := Engine.GetMixer();

-  if (mixer <> nil) then

-    mixer.RemoveStream(Self);

-end;

-

-function TSoftMixerPlaybackStream.IsLoaded(): boolean;

-begin

-  result := assigned(DecodeStream);

-end;

-

-function TSoftMixerPlaybackStream.GetLoop(): boolean;

-begin

-  result := Loop;

-end;

-

-procedure TSoftMixerPlaybackStream.SetLoop(Enabled: boolean);

-begin

-  Loop := Enabled;

-end;

-

-function TSoftMixerPlaybackStream.GetLength(): real;

-begin

-  if assigned(DecodeStream) then

-    result := DecodeStream.Length

-  else

-    result := -1;

-end;

-

-function TSoftMixerPlaybackStream.GetStatus(): TStreamStatus;

-begin

-  result := status;

-end;

-

-{*

- * Note: 44.1kHz to 48kHz conversion or vice versa is not supported

- *  by SDL at the moment. No conversion takes place in this cases.

- *  This is because SDL just converts differences in powers of 2.

- *  So the result might not be that accurate. Although this is not

- *  audible in most cases it needs synchronization with the video

- *  or the lyrics timer.

- *  Using libsamplerate might give better results.  

- *}

-function TSoftMixerPlaybackStream.ReadData(Buffer: PChar; BufSize: integer): integer;

-var

-  decodeBufSize: integer;

-  sampleBufSize: integer;

-  nBytesDecoded: integer;

-  frameSize: integer;

-  remFrameBytes: integer;

-  copyCnt: integer;

-  BytesNeeded: integer;

-begin

-  Result := -1;

-

-  BytesNeeded := BufSize;

-

-  // copy remaining data from the last call to the result-buffer

-  if (BytesAvail > 0) then

-  begin

-    copyCnt := Min(BufSize, BytesAvail);

-    Move(SampleBuffer[SampleBufferPos], Buffer[0], copyCnt);

-    Dec(BytesAvail,  copyCnt);

-    Dec(BytesNeeded, copyCnt);

-    if (BytesNeeded = 0) then

-    begin

-      // Result-Buffer is full -> no need to decode more data.

-      // The sample-buffer might even contain some data for the next call

-      Inc(SampleBufferPos, copyCnt);

-      Result := BufSize;

-      Exit;

-    end;

-  end;

-

-  if not assigned(DecodeStream) then

-    Exit;

-

-  // calc number of bytes to decode

-  decodeBufSize := Ceil(BufSize / cvt.len_ratio);

-  // assure that the decode-size is a multiple of the frame size

-  frameSize := DecodeStream.GetAudioFormatInfo().FrameSize;

-  remFrameBytes := decodeBufSize mod frameSize;

-  if (remFrameBytes > 0) then

-    decodeBufSize := decodeBufSize + (frameSize - remFrameBytes);

-

-  Lock();

-  try

-    // calc buffer size

-    sampleBufSize := decodeBufSize * cvt.len_mult;

-

-    // resize buffer if necessary.

-    // The required buffer-size will be smaller than the result-buffer

-    // in most cases (if the decoded signal is mono or has a lesser bitrate).

-    // If the output-rate is 44.1kHz and the decode-rate is 48kHz or 96kHz it

-    // will be ~1.09 or ~2.18 times bigger. Those extra memory consumption

-    // should be reasonable. If not we should call TDecodeStream.ReadData()

-    // multiple times.

-    // Note: we do not decrease the buffer by the count of bytes used from

-    //   the previous call of this function (bytesAvail). Otherwise the

-    //   buffer will be reallocated each time this function is called just to

-    //   add or remove a few bytes from the buffer.

-    //   By not doing this the buffer's size should be rather stable and it

-    //   will not be reallocated/resized at all if the BufSize params does not

-    //   change in consecutive calls.

-    ReallocMem(SampleBuffer, sampleBufSize);

-    if not assigned(SampleBuffer) then

-      Exit;

-

-    // decode data

-    nBytesDecoded := DecodeStream.ReadData(SampleBuffer, decodeBufSize);

-    if (nBytesDecoded = -1) then

-      Exit;

-

-    // end-of-file reached -> stop playback

-    if (DecodeStream.EOF) then

-      Stop();

-

-    // resample decoded data

-    cvt.buf := PUint8(SampleBuffer);

-    cvt.len := nBytesDecoded;

-    if (SDL_ConvertAudio(@cvt) = -1) then

-      Exit;

-

-    SampleBufferCount := cvt.len_cvt;

-  finally

-    Unlock();

-  end;

-

-  BytesAvail := SampleBufferCount;

-  SampleBufferPos := 0;

-

-  // copy data to result buffer

-  copyCnt := Min(BytesNeeded, BytesAvail);

-  Move(SampleBuffer[0], Buffer[BufSize - BytesNeeded], copyCnt);

-  Dec(BytesAvail,  copyCnt);

-  Dec(BytesNeeded, copyCnt);

-  Inc(SampleBufferPos, copyCnt);

-

-  Result := BufSize - BytesNeeded;

-end;

-

-(* TODO: libsamplerate support

-function TSoftMixerPlaybackStream.ReadData(Buffer: PChar; BufSize: integer): integer;

-var

-  convState: PSRC_STATE;

-  convData: SRC_DATA;

-  error: integer;

-begin

-  // Note: needs mono->stereo conversion, multi-channel->stereo, etc.

-  // maybe we should use SDL for the channel-conversion stuff

-  // and use libsamplerate afterwards for the frequency-conversion

-

-  //convState := src_new(SRC_SINC_MEDIUM_QUALITY, 2, @error);

-  //src_short_to_float_array(input, output, len);

-  convData.

-  if (src_process(convState, @convData) <> 0) then

-  begin

-    Log.LogError(src_strerror(src_error(convState)), 'TSoftMixerPlaybackStream.ReadData');

-    Exit;

-  end;

-  src_float_to_short_array();

-  //src_delete(convState);

-end;

-*)

-

-function TSoftMixerPlaybackStream.GetPCMData(var data: TPCMData): Cardinal;

-var size: 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);

-

-  Lock();

-  Result := Min(SizeOf(data), SampleBufferCount);

-  if (Result > 0) then

-  begin

-    Move(SampleBuffer[0], data[0], Result);

-  end;

-  Unlock();

-*)

-end;

-

-procedure TSoftMixerPlaybackStream.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 := Engine.GetAudioFormatInfo();

-

-  DataIn := AllocMem(FFTSize * SizeOf(Single));

-  if (DataIn = nil) then

-    Exit;

-

-  Lock();

-  // TODO: We just use the first Frames frames, the others are ignored.

-  // This is OK for the equalizer display but not if we want to use

-  // this function for voice-analysis someday (I don't think we want).

-  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;

-  Unlock();

-

-  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

-    // TODO: this might need some work

-    data[i] := Sqrt(data[i]) / 100;

-  end;

-end;

-

-function TSoftMixerPlaybackStream.GetPosition: real;

-begin

-  if assigned(DecodeStream) then

-    result := DecodeStream.Position

-  else

-    result := -1;

-end;

-

-procedure TSoftMixerPlaybackStream.SetPosition(Time: real);

-begin

-  if assigned(DecodeStream) then

-    DecodeStream.Position := Time;

-end;

-

-function TSoftMixerPlaybackStream.GetVolume(): integer;

-begin

-  result := _volume;

-end;

-

-procedure TSoftMixerPlaybackStream.SetVolume(volume: integer);

-begin

-  // clamp volume

-  if (volume > 100) then

-    _volume := 100

-  else if (volume < 0) then

-    _volume := 0

-  else

-    _volume := volume;

-end;

-

-

-{ TAudioPlayback_SoftMixer }

-

-function TAudioPlayback_SoftMixer.InitializePlayback: boolean;

-begin

-  result := false;

-

-  //Log.LogStatus('InitializePlayback', 'UAudioPlayback_SoftMixer');

-

-  if(not InitializeAudioPlaybackEngine()) then

-    Exit;

-

-  MixerStream := TAudioMixerStream.Create;

-

-  if(not StartAudioPlaybackEngine()) then

-    Exit;

-

-  result := true;

-end;

-

-destructor TAudioPlayback_SoftMixer.Destroy;

-begin

-  StopAudioPlaybackEngine();

-

-  FreeAndNil(MusicStream);

-  FreeAndNil(MixerStream);

-  FreeAndNil(FormatInfo);

-

-  inherited Destroy();

-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.Load(const Filename: String): TSoftMixerPlaybackStream;

-var

-  decodeStream: TAudioDecodeStream;

-  playbackStream: TSoftMixerPlaybackStream;

-begin

-  Result := nil;

-

-  decodeStream := AudioDecoder.Open(Filename);

-  if not assigned(decodeStream) then

-  begin

-    Log.LogStatus('LoadSoundFromFile: Sound not found "' + Filename + '"', 'UAudioPlayback_SoftMixer');

-    Exit;

-  end;

-

-  playbackStream := TSoftMixerPlaybackStream.Create(Self);

-  if (not playbackStream.SetDecodeStream(decodeStream)) then

-    Exit;

-

-  result := playbackStream;

-end;

-

-procedure TAudioPlayback_SoftMixer.SetVolume(Volume: integer);

-begin

-  // sets volume only for this application

-  MixerStream.Volume := Volume;

-end;

-

-procedure TAudioPlayback_SoftMixer.SetMusicVolume(Volume: Integer);

-begin

-  if assigned(MusicStream) then

-    MusicStream.Volume := Volume;

-end;

-

-procedure TAudioPlayback_SoftMixer.SetLoop(Enabled: boolean);

-begin

-  if assigned(MusicStream) then

-    MusicStream.SetLoop(Enabled);

-end;

-

-function TAudioPlayback_SoftMixer.Open(const Filename: string): boolean;

-var

-  decodeStream: TAudioDecodeStream;

-begin

-  Result := false;

-

-  // free old MusicStream

-  MusicStream.Free();

-  // and load new one

-  MusicStream := Load(Filename);

-  if not assigned(MusicStream) then

-    Exit;

-

-  //Set Max Volume

-  SetMusicVolume(100);

-

-  Result := true;

-end;

-

-procedure TAudioPlayback_SoftMixer.Rewind;

-begin

-  SetPosition(0);

-end;

-

-procedure TAudioPlayback_SoftMixer.SetPosition(Time: real);

-begin

-  if assigned(MusicStream) then

-    MusicStream.SetPosition(Time);

-end;

-

-function TAudioPlayback_SoftMixer.GetPosition: real;

-begin

-  if assigned(MusicStream) then

-    Result := MusicStream.GetPosition()

-  else

-    Result := -1;

-end;

-

-function TAudioPlayback_SoftMixer.Length: real;

-begin

-  if assigned(MusicStream) then

-    Result := MusicStream.GetLength()

-  else

-    Result := -1;

-end;

-

-procedure TAudioPlayback_SoftMixer.Play;

-begin

-  if assigned(MusicStream) then

-    MusicStream.Play();

-end;

-

-procedure TAudioPlayback_SoftMixer.Pause;

-begin

-  if assigned(MusicStream) then

-    MusicStream.Pause();

-end;

-

-procedure TAudioPlayback_SoftMixer.Stop;

-begin

-  if assigned(MusicStream) then

-    MusicStream.Stop();

-end;

-

-procedure TAudioPlayback_SoftMixer.Close;

-begin

-  if assigned(MusicStream) then

-  begin

-    MusicStream.Close();

-  end;

-end;

-

-function TAudioPlayback_SoftMixer.Finished: boolean;

-begin

-  if assigned(MusicStream) then

-    Result := (MusicStream.GetStatus() = ssStopped)

-  else

-    Result := true;

-end;

-

-//Equalizer

-procedure TAudioPlayback_SoftMixer.GetFFTData(var data: TFFTData);

-begin

-  if assigned(MusicStream) then

-    MusicStream.GetFFTData(data);

-end;

-

-// Interface for Visualizer

-function TAudioPlayback_SoftMixer.GetPCMData(var data: TPCMData): Cardinal;

-begin

-  if assigned(MusicStream) then

-    Result := MusicStream.GetPCMData(data)

-  else

-    Result := 0;

-end;

-

-function TAudioPlayback_SoftMixer.OpenSound(const Filename: String): TAudioPlaybackStream;

-begin

-  Result := Load(Filename);

-end;

-

-procedure TAudioPlayback_SoftMixer.PlaySound(stream: TAudioPlaybackStream);

-begin

-  if assigned(stream) then

-    stream.Play();

-end;

-

-procedure TAudioPlayback_SoftMixer.StopSound(stream: TAudioPlaybackStream);

-begin

-  if assigned(stream) then

-    stream.Stop();

-end;

-

-

-end.

+unit UAudioPlayback_SoftMixer;
+
+interface
+
+{$IFDEF FPC}
+  {$MODE Delphi}
+{$ENDIF}
+
+{$I switches.inc}
+
+
+uses
+  Classes,
+  SysUtils,
+  sdl,
+  UMusic;
+
+type
+  TAudioPlayback_SoftMixer = class;
+
+  TSoftMixerPlaybackStream = class(TAudioPlaybackStream)
+    private
+      Engine: TAudioPlayback_SoftMixer;
+
+      DecodeStream: TAudioDecodeStream;
+      SampleBuffer    : PChar;
+      SampleBufferCount: integer; // number of available bytes in SampleBuffer
+      SampleBufferPos : cardinal;
+      BytesAvail: integer;
+      cvt: TSDL_AudioCVT;
+
+      Status:   TStreamStatus;
+      Loop:     boolean;
+      _volume: integer;
+
+      InternalLock: PSDL_Mutex;
+
+      procedure Reset();
+
+      class function ConvertAudioFormatToSDL(fmt: TAudioSampleFormat): UInt16;
+      function InitFormatConversion(): boolean;
+
+      procedure Lock(); {$IFDEF HasInline}inline;{$ENDIF}
+      procedure Unlock(); {$IFDEF HasInline}inline;{$ENDIF}
+    public
+      constructor Create(Engine: TAudioPlayback_SoftMixer);
+      destructor Destroy(); override;
+
+      function SetDecodeStream(decodeStream: TAudioDecodeStream): boolean;
+
+      procedure Play();                     override;
+      procedure Pause();                    override;
+      procedure Stop();                     override;
+      procedure Close();                    override;
+      function GetLoop(): boolean;          override;
+      procedure SetLoop(Enabled: boolean);  override;
+      function GetLength(): real;           override;
+      function GetStatus(): TStreamStatus;  override;
+
+      function IsLoaded(): boolean;
+
+      function GetVolume(): integer;        override;
+      procedure SetVolume(Volume: integer); override;
+
+      // functions delegated to the decode stream
+      function GetPosition: real;
+      procedure SetPosition(Time: real);
+      function ReadData(Buffer: PChar; BufSize: integer): integer;
+
+      function GetPCMData(var data: TPCMData): Cardinal;
+      procedure GetFFTData(var data: TFFTData);
+  end;
+
+  TAudioMixerStream = class
+    private
+      activeStreams: TList;
+      mixerBuffer: PChar;
+      internalLock: PSDL_Mutex;
+
+      _volume: integer;
+
+      procedure Lock(); {$IFDEF HasInline}inline;{$ENDIF}
+      procedure Unlock(); {$IFDEF HasInline}inline;{$ENDIF}
+
+      function GetVolume(): integer;
+      procedure SetVolume(volume: integer);
+    public
+      constructor Create();
+      destructor Destroy(); override;
+      procedure AddStream(stream: TAudioPlaybackStream);
+      procedure RemoveStream(stream: TAudioPlaybackStream);
+      function ReadData(Buffer: PChar; BufSize: integer): integer;
+
+      property Volume: integer READ GetVolume WRITE SetVolume;
+  end;
+
+  TAudioPlayback_SoftMixer = class( TInterfacedObject, IAudioPlayback )
+    private
+      MusicStream: TSoftMixerPlaybackStream;
+      MixerStream: TAudioMixerStream;
+    protected
+      FormatInfo: TAudioFormatInfo;
+
+      function InitializeAudioPlaybackEngine(): boolean; virtual; abstract;
+      function StartAudioPlaybackEngine(): boolean;      virtual; abstract;
+      procedure StopAudioPlaybackEngine();               virtual; abstract;
+      procedure AudioCallback(buffer: PChar; size: integer); {$IFDEF HasInline}inline;{$ENDIF}
+    public
+      function  GetName: String;                         virtual; abstract;
+
+      function InitializePlayback(): boolean;
+      destructor Destroy; override;
+
+      function Load(const Filename: String): TSoftMixerPlaybackStream;
+
+      procedure SetVolume(Volume: integer);
+      procedure SetMusicVolume(Volume: integer);
+      procedure SetLoop(Enabled: boolean);
+      function Open(const Filename: string): boolean; // true if succeed
+      procedure Rewind;
+      procedure SetPosition(Time: real);
+      procedure Play;
+      procedure Pause;
+
+      procedure Stop;
+      procedure Close;
+      function Finished: boolean;
+      function Length: real;
+      function GetPosition: real;
+
+      // Equalizer
+      procedure GetFFTData(var data: TFFTData);
+
+      // Interface for Visualizer
+      function GetPCMData(var data: TPCMData): Cardinal;
+
+      function GetMixer(): TAudioMixerStream; {$IFDEF HasInline}inline;{$ENDIF}
+      function GetAudioFormatInfo(): TAudioFormatInfo;
+
+      // Sounds
+      function OpenSound(const Filename: String): TAudioPlaybackStream;
+      procedure PlaySound(stream: TAudioPlaybackStream);
+      procedure StopSound(stream: TAudioPlaybackStream);
+  end;
+
+implementation
+
+uses
+  Math,
+  //samplerate,
+  UFFT,
+  ULog,
+  UIni,
+  UMain;
+
+{ TAudioMixerStream }
+
+constructor TAudioMixerStream.Create();
+begin
+  activeStreams := TList.Create;
+  internalLock := SDL_CreateMutex();
+  _volume := 100;
+end;
+
+destructor TAudioMixerStream.Destroy();
+begin
+  if assigned(mixerBuffer) then
+    Freemem(mixerBuffer);
+  activeStreams.Free;
+  SDL_DestroyMutex(internalLock);
+end;
+
+procedure TAudioMixerStream.Lock();
+begin
+  SDL_mutexP(internalLock);
+end;
+
+procedure TAudioMixerStream.Unlock();
+begin
+  SDL_mutexV(internalLock);
+end;
+
+function TAudioMixerStream.GetVolume(): integer;
+begin
+  Lock();
+  result := _volume;
+  Unlock();
+end;
+
+procedure TAudioMixerStream.SetVolume(volume: integer);
+begin
+  Lock();
+  _volume := 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; BufSize: integer): integer;
+var
+  i: integer;
+  size: integer;
+  stream: TSoftMixerPlaybackStream;
+  appVolume: single;
+  needsPacking: boolean;
+begin
+  result := BufSize;
+
+  // zero target-buffer (silence)
+  FillChar(Buffer^, BufSize, 0);
+
+  // resize mixer-buffer if necessary
+  ReallocMem(mixerBuffer, BufSize);
+  if not assigned(mixerBuffer) then
+    Exit;
+
+  Lock();
+
+  // calc application volume
+  // use _volume instead of Volume to prevent recursive locking
+  appVolume := _volume / 100 * SDL_MIX_MAXVOLUME;
+
+  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 := TSoftMixerPlaybackStream(activeStreams[i]);
+    // fetch data from current stream
+    size := stream.ReadData(mixerBuffer, BufSize);
+    if (size > 0) then
+    begin
+      SDL_MixAudio(PUInt8(Buffer), PUInt8(mixerBuffer), size,
+        Trunc(appVolume * stream.Volume / 100));
+    end;
+  end;
+
+  // remove nil-pointers from list
+  if (needsPacking) then
+  begin
+    activeStreams.Pack();
+  end;
+
+  Unlock();
+end;
+
+
+{ TSoftMixerPlaybackStream }
+
+constructor TSoftMixerPlaybackStream.Create(Engine: TAudioPlayback_SoftMixer);
+begin
+  inherited Create();
+  Self.Engine := Engine;
+  internalLock := SDL_CreateMutex();
+  Reset();
+end;
+
+destructor TSoftMixerPlaybackStream.Destroy();
+begin
+  Close();
+  SDL_DestroyMutex(internalLock);
+  inherited Destroy();
+end;
+
+procedure TSoftMixerPlaybackStream.Reset();
+begin
+  Stop();
+  Loop := false;
+  // TODO: use DecodeStream.Unref() instead of Free();
+  FreeAndNil(DecodeStream);
+  FreeMem(SampleBuffer);
+  SampleBuffer := nil;
+  SampleBufferPos := 0;
+  BytesAvail := 0;
+  _volume := 0;
+end;
+
+procedure TSoftMixerPlaybackStream.Lock();
+begin
+  SDL_mutexP(internalLock);
+end;
+
+procedure TSoftMixerPlaybackStream.Unlock();
+begin
+  SDL_mutexV(internalLock);
+end;
+
+class function TSoftMixerPlaybackStream.ConvertAudioFormatToSDL(fmt: TAudioSampleFormat): UInt16;
+begin
+  case fmt of
+    asfU8:     Result := AUDIO_U8;
+    asfS8:     Result := AUDIO_S8;
+    asfU16LSB: Result := AUDIO_U16LSB;
+    asfS16LSB: Result := AUDIO_S16LSB;
+    asfU16MSB: Result := AUDIO_U16MSB;
+    asfS16MSB: Result := AUDIO_S16MSB;
+    asfU16:    Result := AUDIO_U16;
+    asfS16:    Result := AUDIO_S16;
+    else       Result := 0;
+  end;
+end;
+
+function TSoftMixerPlaybackStream.InitFormatConversion(): boolean;
+var
+  err: integer;
+  srcFormat: UInt16;
+  dstFormat: UInt16;
+  srcFormatInfo: TAudioFormatInfo;
+  dstFormatInfo: TAudioFormatInfo;
+begin
+  Result := false;
+
+  srcFormatInfo := DecodeStream.GetAudioFormatInfo();
+  dstFormatInfo := Engine.GetAudioFormatInfo();
+
+  srcFormat := ConvertAudioFormatToSDL(srcFormatInfo.Format);
+  dstFormat := ConvertAudioFormatToSDL(dstFormatInfo.Format);
+
+  if ((srcFormat = 0) or (dstFormat = 0)) then
+  begin
+    Log.LogError('Audio-format not supported by SDL', 'TSoftMixerPlaybackStream.InitFormatConversion');
+    Exit;
+  end;
+
+  if (SDL_BuildAudioCVT(@cvt,
+    srcFormat, srcFormatInfo.Channels, srcFormatInfo.SampleRate,
+    dstFormat, dstFormatInfo.Channels, dstFormatInfo.SampleRate) = -1) then
+  begin
+    Log.LogError(SDL_GetError(), 'TSoftMixerPlaybackStream.InitFormatConversion');
+    Exit;
+  end;
+
+  Result := true;
+end;
+
+function TSoftMixerPlaybackStream.SetDecodeStream(decodeStream: TAudioDecodeStream): boolean;
+begin
+  result := false;
+
+  Reset();
+
+  if not assigned(decodeStream) then
+    Exit;
+  Self.DecodeStream := decodeStream;
+  if not InitFormatConversion() then
+    Exit;
+
+  _volume := 100;
+
+  result := true;
+end;
+
+procedure TSoftMixerPlaybackStream.Close();
+begin
+  Reset();
+end;
+
+procedure TSoftMixerPlaybackStream.Play();
+var
+  mixer: TAudioMixerStream;
+begin
+  if (status <> ssPaused) then
+  begin
+    // rewind
+    if assigned(DecodeStream) then
+      DecodeStream.Position := 0;
+  end;
+  status := ssPlaying;
+
+  mixer := Engine.GetMixer();
+  if (mixer <> nil) then
+    mixer.AddStream(Self);
+end;
+
+procedure TSoftMixerPlaybackStream.Pause();
+var
+  mixer: TAudioMixerStream;
+begin
+  status := ssPaused;
+
+  mixer := Engine.GetMixer();
+  if (mixer <> nil) then
+    mixer.RemoveStream(Self);
+end;
+
+procedure TSoftMixerPlaybackStream.Stop();
+var
+  mixer: TAudioMixerStream;
+begin
+  status := ssStopped;
+
+  mixer := Engine.GetMixer();
+  if (mixer <> nil) then
+    mixer.RemoveStream(Self);
+end;
+
+function TSoftMixerPlaybackStream.IsLoaded(): boolean;
+begin
+  result := assigned(DecodeStream);
+end;
+
+function TSoftMixerPlaybackStream.GetLoop(): boolean;
+begin
+  result := Loop;
+end;
+
+procedure TSoftMixerPlaybackStream.SetLoop(Enabled: boolean);
+begin
+  Loop := Enabled;
+end;
+
+function TSoftMixerPlaybackStream.GetLength(): real;
+begin
+  if assigned(DecodeStream) then
+    result := DecodeStream.Length
+  else
+    result := -1;
+end;
+
+function TSoftMixerPlaybackStream.GetStatus(): TStreamStatus;
+begin
+  result := status;
+end;
+
+{*
+ * Note: 44.1kHz to 48kHz conversion or vice versa is not supported
+ *  by SDL at the moment. No conversion takes place in this cases.
+ *  This is because SDL just converts differences in powers of 2.
+ *  So the result might not be that accurate. Although this is not
+ *  audible in most cases it needs synchronization with the video
+ *  or the lyrics timer.
+ *  Using libsamplerate might give better results.  
+ *}
+function TSoftMixerPlaybackStream.ReadData(Buffer: PChar; BufSize: integer): integer;
+var
+  decodeBufSize: integer;
+  sampleBufSize: integer;
+  nBytesDecoded: integer;
+  frameSize: integer;
+  remFrameBytes: integer;
+  copyCnt: integer;
+  BytesNeeded: integer;
+begin
+  Result := -1;
+
+  BytesNeeded := BufSize;
+
+  // copy remaining data from the last call to the result-buffer
+  if (BytesAvail > 0) then
+  begin
+    copyCnt := Min(BufSize, BytesAvail);
+    Move(SampleBuffer[SampleBufferPos], Buffer[0], copyCnt);
+    Dec(BytesAvail,  copyCnt);
+    Dec(BytesNeeded, copyCnt);
+    if (BytesNeeded = 0) then
+    begin
+      // Result-Buffer is full -> no need to decode more data.
+      // The sample-buffer might even contain some data for the next call
+      Inc(SampleBufferPos, copyCnt);
+      Result := BufSize;
+      Exit;
+    end;
+  end;
+
+  if not assigned(DecodeStream) then
+    Exit;
+
+  // calc number of bytes to decode
+  decodeBufSize := Ceil(BufSize / cvt.len_ratio);
+  // assure that the decode-size is a multiple of the frame size
+  frameSize := DecodeStream.GetAudioFormatInfo().FrameSize;
+  remFrameBytes := decodeBufSize mod frameSize;
+  if (remFrameBytes > 0) then
+    decodeBufSize := decodeBufSize + (frameSize - remFrameBytes);
+
+  Lock();
+  try
+    // calc buffer size
+    sampleBufSize := decodeBufSize * cvt.len_mult;
+
+    // resize buffer if necessary.
+    // The required buffer-size will be smaller than the result-buffer
+    // in most cases (if the decoded signal is mono or has a lesser bitrate).
+    // If the output-rate is 44.1kHz and the decode-rate is 48kHz or 96kHz it
+    // will be ~1.09 or ~2.18 times bigger. Those extra memory consumption
+    // should be reasonable. If not we should call TDecodeStream.ReadData()
+    // multiple times.
+    // Note: we do not decrease the buffer by the count of bytes used from
+    //   the previous call of this function (bytesAvail). Otherwise the
+    //   buffer will be reallocated each time this function is called just to
+    //   add or remove a few bytes from the buffer.
+    //   By not doing this the buffer's size should be rather stable and it
+    //   will not be reallocated/resized at all if the BufSize params does not
+    //   change in consecutive calls.
+    ReallocMem(SampleBuffer, sampleBufSize);
+    if not assigned(SampleBuffer) then
+      Exit;
+
+    // decode data
+    nBytesDecoded := DecodeStream.ReadData(SampleBuffer, decodeBufSize);
+    if (nBytesDecoded = -1) then
+      Exit;
+
+    // end-of-file reached -> stop playback
+    if (DecodeStream.EOF) then
+      Stop();
+
+    // resample decoded data
+    cvt.buf := PUint8(SampleBuffer);
+    cvt.len := nBytesDecoded;
+    if (SDL_ConvertAudio(@cvt) = -1) then
+      Exit;
+
+    SampleBufferCount := cvt.len_cvt;
+  finally
+    Unlock();
+  end;
+
+  BytesAvail := SampleBufferCount;
+  SampleBufferPos := 0;
+
+  // copy data to result buffer
+  copyCnt := Min(BytesNeeded, BytesAvail);
+  Move(SampleBuffer[0], Buffer[BufSize - BytesNeeded], copyCnt);
+  Dec(BytesAvail,  copyCnt);
+  Dec(BytesNeeded, copyCnt);
+  Inc(SampleBufferPos, copyCnt);
+
+  Result := BufSize - BytesNeeded;
+end;
+
+(* TODO: libsamplerate support
+function TSoftMixerPlaybackStream.ReadData(Buffer: PChar; BufSize: integer): integer;
+var
+  convState: PSRC_STATE;
+  convData: SRC_DATA;
+  error: integer;
+begin
+  // Note: needs mono->stereo conversion, multi-channel->stereo, etc.
+  // maybe we should use SDL for the channel-conversion stuff
+  // and use libsamplerate afterwards for the frequency-conversion
+
+  //convState := src_new(SRC_SINC_MEDIUM_QUALITY, 2, @error);
+  //src_short_to_float_array(input, output, len);
+  convData.
+  if (src_process(convState, @convData) <> 0) then
+  begin
+    Log.LogError(src_strerror(src_error(convState)), 'TSoftMixerPlaybackStream.ReadData');
+    Exit;
+  end;
+  src_float_to_short_array();
+  //src_delete(convState);
+end;
+*)
+
+function TSoftMixerPlaybackStream.GetPCMData(var data: TPCMData): Cardinal;
+var
+  nBytes: 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.
+
+  Lock();
+  nBytes := Min(SizeOf(data), SampleBufferCount);
+  if (nBytes > 0) then
+  begin
+    Move(SampleBuffer[0], data, nBytes);
+  end;
+  Unlock();
+  
+  Result := nBytes div SizeOf(TPCMStereoSample);
+end;
+
+procedure TSoftMixerPlaybackStream.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 := Engine.GetAudioFormatInfo();
+
+  DataIn := AllocMem(FFTSize * SizeOf(Single));
+  if (DataIn = nil) then
+    Exit;
+
+  Lock();
+  // TODO: We just use the first Frames frames, the others are ignored.
+  // This is OK for the equalizer display but not if we want to use
+  // this function for voice-analysis someday (I don't think we want).
+  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;
+  Unlock();
+
+  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
+    // TODO: this might need some work
+    data[i] := Sqrt(data[i]) / 100;
+  end;
+end;
+
+function TSoftMixerPlaybackStream.GetPosition: real;
+begin
+  if assigned(DecodeStream) then
+    result := DecodeStream.Position
+  else
+    result := -1;
+end;
+
+procedure TSoftMixerPlaybackStream.SetPosition(Time: real);
+begin
+  if assigned(DecodeStream) then
+    DecodeStream.Position := Time;
+end;
+
+function TSoftMixerPlaybackStream.GetVolume(): integer;
+begin
+  result := _volume;
+end;
+
+procedure TSoftMixerPlaybackStream.SetVolume(volume: integer);
+begin
+  // clamp volume
+  if (volume > 100) then
+    _volume := 100
+  else if (volume < 0) then
+    _volume := 0
+  else
+    _volume := volume;
+end;
+
+
+{ TAudioPlayback_SoftMixer }
+
+function TAudioPlayback_SoftMixer.InitializePlayback: boolean;
+begin
+  result := false;
+
+  //Log.LogStatus('InitializePlayback', 'UAudioPlayback_SoftMixer');
+
+  if(not InitializeAudioPlaybackEngine()) then
+    Exit;
+
+  MixerStream := TAudioMixerStream.Create;
+
+  if(not StartAudioPlaybackEngine()) then
+    Exit;
+
+  result := true;
+end;
+
+destructor TAudioPlayback_SoftMixer.Destroy;
+begin
+  StopAudioPlaybackEngine();
+
+  FreeAndNil(MusicStream);
+  FreeAndNil(MixerStream);
+  FreeAndNil(FormatInfo);
+
+  inherited Destroy();
+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.Load(const Filename: String): TSoftMixerPlaybackStream;
+var
+  decodeStream: TAudioDecodeStream;
+  playbackStream: TSoftMixerPlaybackStream;
+begin
+  Result := nil;
+
+  decodeStream := AudioDecoder.Open(Filename);
+  if not assigned(decodeStream) then
+  begin
+    Log.LogStatus('LoadSoundFromFile: Sound not found "' + Filename + '"', 'UAudioPlayback_SoftMixer');
+    Exit;
+  end;
+
+  playbackStream := TSoftMixerPlaybackStream.Create(Self);
+  if (not playbackStream.SetDecodeStream(decodeStream)) then
+    Exit;
+
+  result := playbackStream;
+end;
+
+procedure TAudioPlayback_SoftMixer.SetVolume(Volume: integer);
+begin
+  // sets volume only for this application
+  MixerStream.Volume := Volume;
+end;
+
+procedure TAudioPlayback_SoftMixer.SetMusicVolume(Volume: Integer);
+begin
+  if assigned(MusicStream) then
+    MusicStream.Volume := Volume;
+end;
+
+procedure TAudioPlayback_SoftMixer.SetLoop(Enabled: boolean);
+begin
+  if assigned(MusicStream) then
+    MusicStream.SetLoop(Enabled);
+end;
+
+function TAudioPlayback_SoftMixer.Open(const Filename: string): boolean;
+var
+  decodeStream: TAudioDecodeStream;
+begin
+  Result := false;
+
+  // free old MusicStream
+  MusicStream.Free();
+  // and load new one
+  MusicStream := Load(Filename);
+  if not assigned(MusicStream) then
+    Exit;
+
+  //Set Max Volume
+  SetMusicVolume(100);
+
+  Result := true;
+end;
+
+procedure TAudioPlayback_SoftMixer.Rewind;
+begin
+  SetPosition(0);
+end;
+
+procedure TAudioPlayback_SoftMixer.SetPosition(Time: real);
+begin
+  if assigned(MusicStream) then
+    MusicStream.SetPosition(Time);
+end;
+
+function TAudioPlayback_SoftMixer.GetPosition: real;
+begin
+  if assigned(MusicStream) then
+    Result := MusicStream.GetPosition()
+  else
+    Result := -1;
+end;
+
+function TAudioPlayback_SoftMixer.Length: real;
+begin
+  if assigned(MusicStream) then
+    Result := MusicStream.GetLength()
+  else
+    Result := -1;
+end;
+
+procedure TAudioPlayback_SoftMixer.Play;
+begin
+  if assigned(MusicStream) then
+    MusicStream.Play();
+end;
+
+procedure TAudioPlayback_SoftMixer.Pause;
+begin
+  if assigned(MusicStream) then
+    MusicStream.Pause();
+end;
+
+procedure TAudioPlayback_SoftMixer.Stop;
+begin
+  if assigned(MusicStream) then
+    MusicStream.Stop();
+end;
+
+procedure TAudioPlayback_SoftMixer.Close;
+begin
+  if assigned(MusicStream) then
+  begin
+    MusicStream.Close();
+  end;
+end;
+
+function TAudioPlayback_SoftMixer.Finished: boolean;
+begin
+  if assigned(MusicStream) then
+    Result := (MusicStream.GetStatus() = ssStopped)
+  else
+    Result := true;
+end;
+
+//Equalizer
+procedure TAudioPlayback_SoftMixer.GetFFTData(var data: TFFTData);
+begin
+  if assigned(MusicStream) then
+    MusicStream.GetFFTData(data);
+end;
+
+// Interface for Visualizer
+function TAudioPlayback_SoftMixer.GetPCMData(var data: TPCMData): Cardinal;
+begin
+  if assigned(MusicStream) then
+    Result := MusicStream.GetPCMData(data)
+  else
+    Result := 0;
+end;
+
+function TAudioPlayback_SoftMixer.OpenSound(const Filename: String): TAudioPlaybackStream;
+begin
+  Result := Load(Filename);
+end;
+
+procedure TAudioPlayback_SoftMixer.PlaySound(stream: TAudioPlaybackStream);
+begin
+  if assigned(stream) then
+    stream.Play();
+end;
+
+procedure TAudioPlayback_SoftMixer.StopSound(stream: TAudioPlaybackStream);
+begin
+  if assigned(stream) then
+    stream.Stop();
+end;
+
+
+end.