1 files changed, 968 insertions, 0 deletions
diff --git a/src/lib/midi/MidiFile.pas b/src/lib/midi/MidiFile.pas
new file mode 100644
index 00000000..acf44c04
--- /dev/null
+++ b/src/lib/midi/MidiFile.pas
@@ -0,0 +1,968 @@
+{
+  Load a midifile and get access to tracks and events
+  I did build this component to convert midifiles to wave files
+  or play the files on a software synthesizer which I'm currenly
+  building.
+
+  version 1.0 first release
+
+  version 1.1
+    added some function
+    function KeyToStr(key : integer) : string;
+    function MyTimeToStr(val : integer) : string;
+    Bpm can be set to change speed
+
+  version 1.2
+    added some functions
+    function  GetTrackLength:integer;
+    function  Ready: boolean;
+
+  version 1.3
+    update by Chulwoong,
+    He knows how to use the MM timer, the timing is much better now, thank you
+
+  for comments/bugs
+  F.Bouwmans
+  fbouwmans@spiditel.nl
+
+  if you think this component is nice and you use it, sent me a short email.
+  I've seen that other of my components have been downloaded a lot, but I've
+  got no clue wether they are actually used.
+  Don't worry because you are free to use these components
+
+  Timing has improved, however because the messages are handled by the normal
+  windows message loop (of the main window) it is still influenced by actions
+  done on the window (minimize/maximize ..).
+  Use of a second thread with higher priority which only handles the
+  timer message should increase performance. If somebody knows such a component
+  which is freeware please let me know.
+
+  interface description:
+
+  procedure ReadFile:
+    actually read the file which is set in Filename
+
+  function GetTrack(index: integer) : TMidiTrack;
+
+  property Filename
+    set/read filename of midifile
+
+  property NumberOfTracks
+    read number of tracks in current file
+
+  property TicksPerQuarter: integer
+    ticks per quarter, tells how to interpret the time value in midi events
+
+  property FileFormat: TFileFormat
+    tells the format of the current midifile
+
+  property Bpm:integer
+    tells Beats per minut
+
+  property OnMidiEvent:TOnMidiEvent
+    called while playing for each midi event
+
+  procedure StartPlaying;
+    start playing the current loaded midifile from the beginning
+
+  procedure StopPlaying;
+    stop playing the current midifile
+
+  procedure PlayToTime(time : integer);
+    if playing yourself then events from last time to this time are produced
+
+
+  function KeyToStr(key : integer) : string;
+      give note string on key value:  e.g. C4
+
+  function MyTimeToStr(val : integer) : string;
+      give time string from msec time
+
+  function  GetTrackLength:integer;
+      gives the track lenght in msec (assuming the bpm at the start oof the file)
+
+  function  Ready: boolean;
+      now you can check wether the playback is finished
+
+}
+
+unit MidiFile;
+
+interface
+
+{$IFDEF FPC}
+  {$MODE Delphi}
+  {$H+} // use long strings
+{$ENDIF}
+
+uses
+  Windows,
+  Messages,
+  Classes,
+  {$IFDEF FPC}
+  WinAllocation,
+  {$ENDIF}
+  SysUtils,
+  UPath;
+
+type
+  TChunkType = (illegal, header, track);
+  TFileFormat = (single, multi_synch, multi_asynch);
+  PByte = ^byte;
+
+  TMidiEvent = record
+    event: byte;
+    data1: byte;
+    data2: byte;
+    str: string;
+    dticks: integer;
+    time: integer;
+    mtime: integer;
+    len: integer;
+  end;
+  PMidiEvent = ^TMidiEvent;
+
+  TOnMidiEvent = procedure(event: PMidiEvent) of object;
+  TEvent = procedure of object;
+
+  TMidiTrack = class(TObject)
+  protected
+    events: TList;
+      name: string;
+    instrument: string;
+    currentTime: integer;
+    currentPos: integer;
+    ready: boolean;
+    trackLenght: integer;
+    procedure checkReady;
+  public
+    OnMidiEvent: TOnMidiEvent;
+    OnTrackReady: TEvent;
+    constructor Create;
+    destructor Destroy; override;
+
+    procedure Rewind(pos: integer);
+    procedure PlayUntil(pos: integer);
+    procedure GoUntil(pos: integer);
+
+    procedure putEvent(event: PMidiEvent);
+    function getEvent(index: integer): PMidiEvent;
+    function getName: string;
+    function getInstrument: string;
+    function getEventCount: integer;
+    function getCurrentTime: integer;
+    function getTrackLength: integer;
+    function isReady:boolean;
+  end;
+
+  TMidiFile = class(TComponent)
+  private
+    { Private declarations }
+    procedure MidiTimer(sender : TObject);
+    procedure WndProc(var Msg : TMessage);
+  protected
+    { Protected declarations }
+    midiFile: TBinaryFileStream;
+    chunkType: TChunkType;
+    chunkLength: integer;
+    chunkData: PByte;
+    chunkIndex: PByte;
+    chunkEnd: PByte;
+    FPriority: DWORD;
+
+    // midi file attributes
+    FFileFormat: TFileFormat;
+    numberTracks: integer;
+    deltaTicks: integer;
+    FBpm: integer;
+    FBeatsPerMeasure: integer;
+    FusPerTick: double;
+    FFilename: IPath;
+
+    Tracks: TList;
+    currentTrack: TMidiTrack;
+    FOnMidiEvent: TOnMidiEvent;
+    FOnUpdateEvent: TNotifyEvent;
+
+    // playing attributes
+    playing: boolean;
+    PlayStartTime: integer;
+    currentTime: integer; // Current playtime in msec
+    currentPos: Double; // Current Position in ticks
+
+    procedure OnTrackReady;
+    procedure SetFilename(val: IPath);
+    procedure ReadChunkHeader;
+    procedure ReadChunkContent;
+    procedure ReadChunk;
+    procedure ProcessHeaderChunk;
+    procedure ProcessTrackChunk;
+    function ReadVarLength: integer;
+    function ReadString(l: integer): string;
+    procedure SetOnMidiEvent(handler: TOnMidiEvent);
+    procedure SetBpm(val: integer);
+  public
+    { Public declarations }
+    constructor Create(AOwner: TComponent); override;
+    destructor Destroy; override;
+
+    procedure ReadFile;
+    function GetTrack(index: integer): TMidiTrack;
+
+    procedure StartPlaying;
+    procedure StopPlaying;
+    procedure ContinuePlaying;
+
+    procedure PlayToTime(time: integer);
+    procedure GoToTime(time: integer);
+    function GetCurrentTime: integer;
+    function GetFusPerTick : Double;
+    function  GetTrackLength:integer;
+    function  Ready: boolean;
+  published
+    { Published declarations }
+    property Filename: IPath read FFilename write SetFilename;
+    property NumberOfTracks: integer read numberTracks;
+    property TicksPerQuarter: integer read deltaTicks;
+    property FileFormat: TFileFormat read FFileFormat;
+    property Bpm: integer read FBpm write SetBpm;
+    property OnMidiEvent: TOnMidiEvent read FOnMidiEvent write SetOnMidiEvent;
+    property OnUpdateEvent: TNotifyEvent read FOnUpdateEvent write FOnUpdateEvent;
+  end;
+
+function KeyToStr(key: integer): string;
+function MyTimeToStr(val: integer): string;
+procedure Register;
+
+implementation
+
+uses mmsystem;
+
+type
+{$IFDEF FPC}
+  TTimerProc = TTIMECALLBACK;
+  TTimeCaps = TIMECAPS;
+{$ELSE}
+  TTimerProc = TFNTimeCallBack;
+{$ENDIF}
+
+const TIMER_RESOLUTION=10;
+const WM_MULTIMEDIA_TIMER=WM_USER+127;
+
+var MIDIFileHandle : HWND;
+    TimerProc      : TTimerProc;
+    MIDITimerID    : Integer;
+    TimerPeriod     : Integer;
+
+procedure TimerCallBackProc(uTimerID,uMsg: Cardinal; dwUser,dwParam1,dwParam2:DWORD);stdcall;
+begin
+     PostMessage(HWND(dwUser),WM_MULTIMEDIA_TIMER,0,0);
+end;
+
+procedure SetMIDITimer;
+  var TimeCaps    : TTimeCaps;
+begin
+  timeGetDevCaps(@TimeCaps,SizeOf(TimeCaps));
+  if TIMER_RESOLUTION < TimeCaps.wPeriodMin then
+    TimerPeriod:=TimeCaps.wPeriodMin
+  else if TIMER_RESOLUTION > TimeCaps.wPeriodMax then
+    TimerPeriod:=TimeCaps.wPeriodMax
+  else
+    TimerPeriod:=TIMER_RESOLUTION;
+
+  timeBeginPeriod(TimerPeriod);
+  MIDITimerID:=timeSetEvent(TimerPeriod,TimerPeriod,TimerProc,
+                            DWORD(MIDIFileHandle),TIME_PERIODIC);
+  if MIDITimerID=0 then
+    timeEndPeriod(TimerPeriod);
+end;
+
+procedure KillMIDITimer;
+begin
+  timeKillEvent(MIDITimerID);
+  timeEndPeriod(TimerPeriod);
+end;
+
+constructor TMidiTrack.Create;
+begin
+  inherited Create;
+  events := TList.Create;
+  currentTime := 0;
+  currentPos := 0;
+end;
+
+destructor TMidiTrack.Destroy;
+var
+  i: integer;
+begin
+  for i := 0 to events.count - 1 do
+    Dispose(PMidiEvent(events.items[i]));
+  events.Free;
+  inherited Destroy;
+end;
+
+procedure TMidiTRack.putEvent(event: PMidiEvent);
+var
+  command: integer;
+  i: integer;
+  pevent: PMidiEvent;
+begin
+  if (event.event = $FF) then
+  begin
+    if (event.data1 = 3) then
+      name := event.str;
+    if (event.data1 = 4) then
+      instrument := event.str;
+  end;
+  currentTime := currentTime + event.dticks;
+  event.time := currentTime; // for the moment just add dticks
+  event.len := 0;
+  events.add(TObject(event));
+  command := event.event and $F0;
+
+  if ((command = $80) // note off
+    or ((command = $90) and (event.data2 = 0))) //note on with speed 0
+  then
+  begin
+    // this is a note off, try to find the accompanion note on
+    command := event.event or $90;
+    i := events.count - 2;
+    while i >= 0 do
+    begin
+      pevent := PMidiEvent(events[i]);
+      if (pevent.event = command) and
+        (pevent.data1 = event.data1)
+        then
+      begin
+        pevent.len := currentTIme - pevent.time;
+        i := 0;
+        event.len := -1;
+      end;
+      dec(i);
+    end;
+  end;
+end;
+
+function TMidiTrack.getName: string;
+begin
+  result := name;
+end;
+
+function TMidiTrack.getInstrument: string;
+begin
+  result := instrument;
+end;
+
+function TMiditrack.getEventCount: integer;
+begin
+  result := events.count;
+end;
+
+function TMiditrack.getEvent(index: integer): PMidiEvent;
+begin
+  if ((index < events.count) and (index >= 0)) then
+    result := events[index]
+  else
+    result := nil;
+end;
+
+function TMiditrack.getCurrentTime: integer;
+begin
+  result := currentTime;
+end;
+
+procedure TMiditrack.Rewind(pos: integer);
+begin
+  if currentPos = events.count then
+    dec(currentPos);
+  while ((currentPos > 0) and
+    (PMidiEvent(events[currentPos]).time > pos))
+    do
+  begin
+    dec(currentPos);
+  end;
+  checkReady;
+end;
+
+procedure TMiditrack.PlayUntil(pos: integer);
+begin
+  if assigned(OnMidiEvent) then
+  begin
+    while ((currentPos < events.count) and
+      (PMidiEvent(events[currentPos]).time < pos)) do
+    begin
+      OnMidiEvent(PMidiEvent(events[currentPos]));
+      inc(currentPos);
+    end;
+  end;
+  checkReady;
+end;
+
+procedure TMidiTrack.GoUntil(pos: integer);
+begin
+  while ((currentPos < events.count) and
+    (PMidiEvent(events[currentPos]).time < pos)) do
+  begin
+    inc(currentPos);
+  end;
+  checkReady;
+end;
+
+procedure TMidiTrack.checkReady;
+begin
+  if currentPos >= events.count then
+  begin
+    ready := true;
+    if assigned(OnTrackReady) then
+      OnTrackReady;
+  end
+  else
+    ready := false;
+end;
+
+function TMidiTrack.getTrackLength: integer;
+begin
+  result := PMidiEvent(events[events.count-1]).time
+end;
+
+function TMidiTrack.isReady: boolean;
+begin
+  result := ready;
+end;
+
+constructor TMidifile.Create(AOwner: TComponent);
+begin
+  inherited Create(AOWner);
+  MIDIFileHandle:=AllocateHWnd(WndProc);
+  chunkData := nil;
+  chunkType := illegal;
+  Tracks := TList.Create;
+  TimerProc:=@TimerCallBackProc;
+  FPriority:=GetPriorityClass(MIDIFileHandle);
+end;
+
+destructor TMidifile.Destroy;
+var
+  i: integer;
+begin
+  if not (chunkData = nil) then FreeMem(chunkData);
+  for i := 0 to Tracks.Count - 1 do
+    TMidiTrack(Tracks.Items[i]).Free;
+  Tracks.Free;
+  SetPriorityClass(MIDIFileHandle,FPriority);
+
+  if MIDITimerID<>0 then KillMIDITimer;
+
+  DeallocateHWnd(MIDIFileHandle);
+
+  inherited Destroy;
+end;
+
+function TMidiFile.GetTrack(index: integer): TMidiTrack;
+begin
+  result := Tracks.Items[index];
+end;
+
+procedure TMidifile.SetFilename(val: IPath);
+begin
+  FFilename := val;
+//  ReadFile;
+end;
+
+procedure TMidifile.SetOnMidiEvent(handler: TOnMidiEvent);
+var
+  i: integer;
+begin
+//  if not (FOnMidiEvent = handler) then
+//  begin
+  FOnMidiEvent := handler;
+  for i := 0 to tracks.count - 1 do
+    TMidiTrack(tracks.items[i]).OnMidiEvent := handler;
+//  end;
+end;
+
+{$WARNINGS OFF}
+procedure TMidifile.MidiTimer(Sender: TObject);
+begin
+  if playing then
+  begin
+    PlayToTime(GetTickCount - PlayStartTime);
+    if assigned(FOnUpdateEvent) then FOnUpdateEvent(self);
+  end;
+end;
+{$WARNINGS ON}
+
+procedure TMidifile.StartPlaying;
+var
+  i: integer;
+begin
+  for i := 0 to tracks.count - 1 do
+    TMidiTrack(tracks[i]).Rewind(0);
+  playStartTime := getTickCount;
+  playing := true;
+
+  SetPriorityClass(MIDIFileHandle,REALTIME_PRIORITY_CLASS);
+
+  SetMIDITimer;
+  currentPos := 0.0;
+  currentTime := 0;
+end;
+
+{$WARNINGS OFF}
+procedure TMidifile.ContinuePlaying;
+begin
+  PlayStartTime := GetTickCount - currentTime;
+  playing := true;
+
+  SetPriorityClass(MIDIFileHandle,REALTIME_PRIORITY_CLASS);
+
+  SetMIDITimer;
+end;
+{$WARNINGS ON}
+
+procedure TMidifile.StopPlaying;
+begin
+  playing := false;
+  KillMIDITimer;
+  SetPriorityClass(MIDIFileHandle,FPriority);
+end;
+
+function TMidiFile.GetCurrentTime: integer;
+begin
+  Result := currentTime;
+end;
+
+procedure TMidifile.PlayToTime(time: integer);
+var
+  i: integer;
+  track: TMidiTrack;
+  pos: integer;
+  deltaTime: integer;
+begin
+  // calculate the pos in the file.
+  // pos is actually tick
+  // Current FusPerTick is uses to determine the actual pos
+
+  deltaTime := time - currentTime;
+  currentPos := currentPos + (deltaTime * 1000) / FusPerTick;
+  pos := round(currentPos);
+
+  for i := 0 to tracks.count - 1 do
+  begin
+    TMidiTrack(tracks.items[i]).PlayUntil(pos);
+  end;
+  currentTime := time;
+end;
+
+procedure TMidifile.GoToTime(time: integer);
+var
+  i: integer;
+  track: TMidiTrack;
+  pos: integer;
+begin
+  // this function should be changed because FusPerTick might not be constant
+  pos := round((time * 1000) / FusPerTick);
+  for i := 0 to tracks.count - 1 do
+  begin
+    TMidiTrack(tracks.items[i]).Rewind(0);
+    TMidiTrack(tracks.items[i]).GoUntil(pos);
+  end;
+end;
+
+procedure TMidifile.SetBpm(val: integer);
+var
+  us_per_quarter: integer;
+begin
+  if not (val = FBpm) then
+  begin
+    us_per_quarter := 60000000 div val;
+
+    FBpm := 60000000 div us_per_quarter;
+    FusPerTick := us_per_quarter / deltaTicks;
+  end;
+end;
+
+procedure TMidifile.ReadChunkHeader;
+var
+  theByte: array[0..7] of byte;
+begin
+  midiFile.Read(theByte[0], 8);
+  if (theByte[0] = $4D) and (theByte[1] = $54) then
+  begin
+    if (theByte[2] = $68) and (theByte[3] = $64) then
+      chunkType := header
+    else if (theByte[2] = $72) and (theByte[3] = $6B) then
+      chunkType := track
+    else
+      chunkType := illegal;
+  end
+  else
+  begin
+    chunkType := illegal;
+  end;
+  chunkLength := theByte[7] + theByte[6] * $100 + theByte[5] * $10000 + theByte[4] * $1000000;
+end;
+
+procedure TMidifile.ReadChunkContent;
+begin
+  if not (chunkData = nil) then
+    FreeMem(chunkData);
+  GetMem(chunkData, chunkLength + 10);
+  midiFile.Read(chunkData^, chunkLength);
+  chunkIndex := chunkData;
+  chunkEnd := PByte(integer(chunkIndex) + integer(chunkLength) - 1);
+end;
+
+procedure TMidifile.ReadChunk;
+begin
+  ReadChunkHeader;
+  ReadChunkContent;
+  case chunkType of
+    header:
+      ProcessHeaderChunk;
+    track:
+      ProcessTrackCHunk;
+  end;
+end;
+
+procedure TMidifile.ProcessHeaderChunk;
+begin
+  chunkIndex := chunkData;
+  inc(chunkIndex);
+  if chunkType = header then
+  begin
+    case chunkIndex^ of
+      0: FfileFormat := single;
+      1: FfileFormat := multi_synch;
+      2: FfileFormat := multi_asynch;
+    end;
+    inc(chunkIndex);
+    numberTracks := chunkIndex^ * $100;
+    inc(chunkIndex);
+    numberTracks := numberTracks + chunkIndex^;
+    inc(chunkIndex);
+    deltaTicks := chunkIndex^ * $100;
+    inc(chunkIndex);
+    deltaTicks := deltaTicks + chunkIndex^;
+  end;
+end;
+
+procedure TMidifile.ProcessTrackChunk;
+var
+  dTime: integer;
+  event: integer;
+  len: integer;
+  str: string;
+  midiEvent: PMidiEvent;
+  i: integer;
+  us_per_quarter: integer;
+begin
+  chunkIndex := chunkData;
+//  inc(chunkIndex);
+  event := 0;
+  if chunkType = track then
+  begin
+    currentTrack := TMidiTrack.Create;
+    currentTrack.OnMidiEvent := FOnMidiEvent;
+    Tracks.add(currentTrack);
+    while integer(chunkIndex) < integer(chunkEnd) do
+    begin
+      // each event starts with var length delta time
+      dTime := ReadVarLength;
+      if chunkIndex^ >= $80 then
+      begin
+        event := chunkIndex^;
+        inc(chunkIndex);
+      end;
+      // else it is a running status event (just the same event as before)
+
+      if event = $FF then
+      begin
+{        case chunkIndex^ of
+        $00: // sequence number, not implemented jet
+            begin
+              inc(chunkIndex); // $02
+              inc(chunkIndex);
+            end;
+        $01 .. $0f: // text events  FF ty len text
+            begin
+              New(midiEvent);
+              midiEvent.event := $FF;
+              midiEvent.data1 := chunkIndex^;     // type is stored in data1
+              midiEvent.dticks := dtime;
+
+              inc(chunkIndex);
+              len := ReadVarLength;
+              midiEvent.str    := ReadString(len);
+
+              currentTrack.putEvent(midiEvent);
+            end;
+        $20: // Midi channel prefix  FF 20 01 cc
+             begin
+               inc(chunkIndex); // $01
+               inc(chunkIndex); // channel
+               inc(chunkIndex);
+             end;
+        $2F: // End of track FF 2F 00
+             begin
+               inc(chunkIndex); // $00
+               inc(chunkIndex);
+             end;
+        $51: // Set Tempo  FF 51 03 tttttt
+             begin
+               inc(chunkIndex); // $03
+               inc(chunkIndex); // tt
+               inc(chunkIndex); // tt
+               inc(chunkIndex); // tt
+               inc(chunkIndex);
+             end;
+        $54: // SMPTE offset  FF 54 05 hr mn se fr ff
+             begin
+               inc(chunkIndex); // $05
+               inc(chunkIndex); // hr
+               inc(chunkIndex); // mn
+               inc(chunkIndex); // se
+               inc(chunkIndex); // fr
+               inc(chunkIndex); // ff
+               inc(chunkIndex);
+             end;
+        $58: // Time signature FF 58 04 nn dd cc bb
+             begin
+               inc(chunkIndex); // $04
+               inc(chunkIndex); // nn
+               inc(chunkIndex); // dd
+               inc(chunkIndex); // cc
+               inc(chunkIndex); // bb
+               inc(chunkIndex);
+             end;
+        $59: // Key signature FF 59 02 df mi
+             begin
+               inc(chunkIndex); // $02
+               inc(chunkIndex); // df
+               inc(chunkIndex); // mi
+               inc(chunkIndex);
+             end;
+        $7F: // Sequence specific Meta-event
+            begin
+              inc(chunkIndex);
+              len := ReadVarLength;
+              str := ReadString(len);
+            end;
+        else // unknown meta event
+        }
+        begin
+          New(midiEvent);
+          midiEvent.event := $FF;
+          midiEvent.data1 := chunkIndex^; // type is stored in data1
+          midiEvent.dticks := dtime;
+
+          inc(chunkIndex);
+          len := ReadVarLength;
+          midiEvent.str := ReadString(len);
+          currentTrack.putEvent(midiEvent);
+
+          case midiEvent.data1 of
+            $51:
+              begin
+                us_per_quarter :=
+                  (integer(byte(midiEvent.str[1])) shl 16 +
+                  integer(byte(midiEvent.str[2])) shl 8 +
+                  integer(byte(midiEvent.str[3])));
+                FBpm := 60000000 div us_per_quarter;
+                FusPerTick := us_per_quarter / deltaTicks;
+              end;
+          end;
+        end;
+//        end;
+      end
+      else
+      begin
+      // these are all midi events
+        New(midiEvent);
+        midiEvent.event := event;
+        midiEvent.dticks := dtime;
+//         inc(chunkIndex);
+        case event of
+          $80..$8F, // note off
+          $90..$9F, // note on
+          $A0..$AF, // key aftertouch
+          $B0..$BF, // control change
+          $E0..$EF: // pitch wheel change
+            begin
+              midiEvent.data1 := chunkIndex^; inc(chunkIndex);
+              midiEvent.data2 := chunkIndex^; inc(chunkIndex);
+            end;
+          $C0..$CF, // program change
+          $D0..$DF: // channel aftertouch
+            begin
+              midiEvent.data1 := chunkIndex^; inc(chunkIndex);
+            end;
+        else
+           // error
+        end;
+        currentTrack.putEvent(midiEvent);
+      end;
+    end;
+  end;
+end;
+
+
+function TMidifile.ReadVarLength: integer;
+var
+  i: integer;
+  b: byte;
+begin
+  b := 128;
+  i := 0;
+  while b > 127 do
+  begin
+    i := i shl 7;
+    b := chunkIndex^;
+    i := i + b and $7F;
+    inc(chunkIndex);
+  end;
+  result := i;
+end;
+
+function TMidifile.ReadString(l: integer): string;
+var
+  s: PChar;
+  i: integer;
+begin
+  GetMem(s, l + 1); ;
+  s[l] := chr(0);
+  for i := 0 to l - 1 do
+  begin
+    s[i] := Chr(chunkIndex^);
+    inc(chunkIndex);
+  end;
+  result := string(s);
+end;
+
+procedure TMidifile.ReadFile;
+var
+  i: integer;
+begin
+  for i := 0 to Tracks.Count - 1 do
+    TMidiTrack(Tracks.Items[i]).Free;
+  Tracks.Clear;
+  chunkType := illegal;
+
+  midiFile := TBinaryFileStream.Create(FFilename, fmOpenRead);
+  while (midiFile.Position < midiFile.Size) do
+    ReadChunk;
+  FreeAndNil(midiFile);
+  numberTracks := Tracks.Count;
+end;
+
+function KeyToStr(key: integer): string;
+var
+  n: integer;
+  str: string;
+begin
+  n := key mod 12;
+  case n of
+    0: str := 'C';
+    1: str := 'C#';
+    2: str := 'D';
+    3: str := 'D#';
+    4: str := 'E';
+    5: str := 'F';
+    6: str := 'F#';
+    7: str := 'G';
+    8: str := 'G#';
+    9: str := 'A';
+    10: str := 'A#';
+    11: str := 'B';
+  end;
+  Result := str + IntToStr(key div 12);
+end;
+
+function IntToLenStr(val: integer; len: integer): string;
+var
+  str: string;
+begin
+  str := IntToStr(val);
+  while Length(str) < len do
+    str := '0' + str;
+  Result := str;
+end;
+
+function MyTimeToStr(val: integer): string;
+ var
+  hour: integer;
+  min: integer;
+  sec: integer;
+  msec: integer;
+begin
+  msec := val mod 1000;
+  sec := val div 1000;
+  min := sec div 60;
+  sec := sec mod 60;
+  hour := min div 60;
+  min := min mod 60;
+  Result := IntToStr(hour) + ':' + IntToLenStr(min, 2) + ':' + IntToLenStr(sec, 2) + '.' + IntToLenStr(msec, 3);
+end;
+
+function TMidiFIle.GetFusPerTick : Double;
+begin
+  Result := FusPerTick;
+end;
+
+function  TMidiFIle.GetTrackLength:integer;
+var i,length : integer;
+    time : extended;
+begin
+  length := 0;
+  for i := 0 to Tracks.Count - 1 do
+    if TMidiTrack(Tracks.Items[i]).getTrackLength > length then
+      length := TMidiTrack(Tracks.Items[i]).getTrackLength;
+  time := length * FusPerTick;
+  time := time / 1000.0;
+  result := round(time);
+end;
+
+function  TMidiFIle.Ready: boolean;
+var i : integer;
+begin
+  result := true;
+  for i := 0 to Tracks.Count - 1 do
+    if not TMidiTrack(Tracks.Items[i]).isready then
+      result := false;
+end;
+
+procedure TMidiFile.OnTrackReady;
+begin
+  if ready then
+    if assigned(FOnUpdateEvent) then FOnUpdateEvent(self);
+end;
+
+procedure TMidiFile.WndProc(var Msg : TMessage);
+begin
+  with MSG do
+  begin
+    case Msg of
+      WM_MULTIMEDIA_TIMER:
+      begin
+        //try
+          MidiTimer(self);
+        //except
+        // Note: HandleException() is called by default if exception is not handled
+        //  Application.HandleException(Self);
+        //end;
+      end;
+    else
+      begin
+        Result := DefWindowProc(MIDIFileHandle, Msg, wParam, lParam);
+      end;
+    end;
+  end;
+end;
+
+procedure Register;
+begin
+  RegisterComponents('Synth', [TMidiFile]);
+end;
+
+end.
+