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Anthony · Guest

Hi all,

I am trying to create my own class as below but I have one problem and
two questions.
If you have any ideas about these, please leave your comment. It would
be greatly appreciated.

Problem #1:

MediaPlayer1.Open;

this line occurred CPU error from Delphi IDE at run time which is
saying "integer divide by zero at.".
As you can see below, I was trying to use TMediaPlayer inside of my own
class. I guess I made
something wrong in my codes. Please tell me what was wrong.

Question #1:

in case of my class definition, is this okay to call merely inherited
in constructor and destructor?

inherited Create;

inherited Destroy;

Question #2:

I assigned "self" from TForm1 into TMediaPlayer as parent window.
Of course, there is no error but I want to make sure if I was right.

The below is the codes from Unit1 and class unit.

///////////////////////////////// Unit1
var
Form1: TForm1;

implementation

uses RecordRadio_;
var RecordRadio1: TRecordRadio;

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
RecordRadio1 := TRecordRadio.Create(Self);
RecordRadio1.Start;
RecordRadio1.Duration := 2;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
RecordRadio1.Free;
end;

///////////////////////////////// RecordRadio class unit

unit RecordRadio_;

interface

uses MPlayer, SysUtils, ExtCtrls, Classes, Controls;

type
TRecordRadio = class

MediaPlayer1: TMediaPlayer;

private
FDuration: Integer;
FRate: Longint;
FResolution: Word;
FChannels: Word;
FStartTime: TDateTime;
function Get_FileName: String;
function Get_FilePath: String;
public
constructor Create(AOwner:TComponent);
destructor Destroy;
procedure Start;
procedure Stop;

// Read inside and write outside.
property Channels: Word write FChannels default 2;
property Resolution: Word write FResolution default 16;
property Rate: Longint write FRate default 44100;
property Duration: Integer write FDuration default 1; // in min.

// Read outside and write outside.
property StartTime: TDateTime read FStartTime write FStartTime;

// Need internal actions.
property FileName: String read Get_FileName;
property FilePath: String read Get_FilePath;

procedure CreateDummyWaveFile;
end;

implementation

{ TRecordRadio }

procedure TRecordRadio.CreateDummyWaveFile;
type
TWavHeader = record
rId : longint;
rLen : longint;
wId : longint;
fId : longint;
fLen : longint;
wFormatTag : word;
nChannels : word;
nSamplesPerSec : longint;
nAvgBytesPerSec : longint;
nBlockAlign : word;
wBitsPerSample : word;
dId : longint;
wSampleLength : longint;
end;

var
wf : file of TWavHeader;
wh : TWavHeader;
begin

wh.rId := $46464952;
wh.rLen := 36;
wh.wId := $45564157;
wh.fId := $20746d66;
wh.fLen := 16;
wh.wFormatTag := 1;
wh.nChannels := FChannels;
wh.nSamplesPerSec := FRate;
wh.nAvgBytesPerSec := FChannels * FRate * ( FResolution div Cool

;
wh.nBlockAlign := FChannels*( FResolution div Cool

;
wh.wBitsPerSample := FResolution;
wh.dId := $61746164;
wh.wSampleLength := 0;
AssignFile(wf,'c:\tmp.wav');
Rewrite(wf);
Write(wf,wh);
CloseFile(wf);
end;

constructor TRecordRadio.Create(AOwner: TComponent);
begin
inherited Create;
MediaPlayer1 := TMediaPlayer.Create(AOwner);
MediaPlayer1.Parent := TWinControl(AOwner);
end;

destructor TRecordRadio.Destroy;
begin
inherited Destroy;
MediaPlayer1.Free;
end;

function TRecordRadio.Get_FileName: String;
begin
end;

function TRecordRadio.Get_FilePath: String;
begin
end;

procedure TRecordRadio.Start;
begin
CreateDummyWaveFile;

// MediaPlayer1.Visible := False;
FStartTime := Time;

if FileExists( 'c:\tmp.wav' ) then
begin
MediaPlayer1.DeviceType:= dtAutoSelect;
MediaPlayer1.FileName:= 'c:\tmp.wav';

////////////////////////////////////////////////////////////////// This
code raised CPU error at run-time.
MediaPlayer1.Open;

MediaPlayer1.StartRecording;
MediaPlayer1.Stop;
end;

end;

procedure TRecordRadio.Stop;
begin
MediaPlayer1.Stop;
end;

end.