diff options
| author | jaybinks <jaybinks@b956fd51-792f-4845-bead-9b4dfca2ff2c> | 2007-09-05 12:02:06 +0000 |
|---|---|---|
| committer | jaybinks <jaybinks@b956fd51-792f-4845-bead-9b4dfca2ff2c> | 2007-09-05 12:02:06 +0000 |
| commit | 30343a531999b5e50673ee1731f1c54cbc008dfd (patch) | |
| tree | ac7bd5051ad29aa13fe5a854d553b49ececcd4a8 /Game/Code/lib/midi/MidiFile.pas | |
| parent | fee5e834a23f11ea42365b9c5f7336b9c5c58bc0 (diff) | |
| download | usdx-30343a531999b5e50673ee1731f1c54cbc008dfd.tar.gz usdx-30343a531999b5e50673ee1731f1c54cbc008dfd.tar.xz usdx-30343a531999b5e50673ee1731f1c54cbc008dfd.zip | |
added 3rd party dependencies ( except Jedi-SDL )
modified DPR to statically include all files needed (using relative paths)
this means 3rd party components should not need installation in the IDE, or adding to search paths.
git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@368 b956fd51-792f-4845-bead-9b4dfca2ff2c
Diffstat (limited to 'Game/Code/lib/midi/MidiFile.pas')
| -rw-r--r-- | Game/Code/lib/midi/MidiFile.pas | 947 |
1 files changed, 947 insertions, 0 deletions
diff --git a/Game/Code/lib/midi/MidiFile.pas b/Game/Code/lib/midi/MidiFile.pas new file mode 100644 index 00000000..5c15481e --- /dev/null +++ b/Game/Code/lib/midi/MidiFile.pas @@ -0,0 +1,947 @@ +{
+ 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
+
+uses
+ Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
+ stdctrls, ExtCtrls, WinProcs;
+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: file of byte;
+ 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: string;
+
+ 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: string);
+ 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: string 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 TTimerProc=procedure(uTimerID,uMsg: Integer; dwUser,dwParam1,dwParam2:DWORD);stdcall;
+
+const TIMER_RESOLUTION=10;
+const WM_MULTIMEDIA_TIMER=WM_USER+127;
+
+var MIDIFileHandle : HWND;
+ TimerProc : TTimerProc;
+ MIDITimerID : Integer;
+ TimerPeriod : Integer;
+
+procedure TimerCallBackProc(uTimerID,uMsg: Integer; 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: string);
+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;
+
+procedure TMidifile.MidiTimer(Sender: TObject);
+begin
+ if playing then
+ begin
+ PlayToTime(GetTickCount - PlayStartTime);
+ if assigned(FOnUpdateEvent) then FOnUpdateEvent(self);
+ end;
+end;
+
+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;
+
+procedure TMidifile.ContinuePlaying;
+begin
+ PlayStartTime := GetTickCount - currentTime;
+ playing := true;
+
+ SetPriorityClass(MIDIFileHandle,REALTIME_PRIORITY_CLASS);
+
+ SetMIDITimer;
+end;
+
+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
+ BlockRead(midiFile, theByte, 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);
+ BlockRead(midiFile, 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;
+
+ AssignFile(midiFile, FFilename);
+ FileMode := 0;
+ Reset(midiFile);
+ while not eof(midiFile) do
+ ReadChunk;
+ CloseFile(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
+ 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.
+
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