Mega Code Archive
How to determinate the bitrate of a WAV file
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Title: How to determinate the bitrate of a WAV file
{....}
private
procedure OpenMedia(WaveFile : string);
function GetStatus(StatusRequested : DWord) : longint;
procedure CloseMedia;
{....}
var
MyError, dwFlags: Longint;
FDeviceID : Word;
{....}
uses
MMSystem;
{....}
procedure TForm1.OpenMedia(WaveFile: string);
var
MyOpenParms: TMCI_Open_Parms;
begin
with MyOpenParms do
begin
dwCallback := Handle; // TForm1.Handle
lpstrDeviceType := PChar(WaveAudio);
lpstrElementName := PChar(WaveFile);
end; {with MyOpenParms}
dwFlags := MCI_WAIT or MCI_OPEN_ELEMENT or MCI_OPEN_TYPE;
MyError := mciSendCommand(0, MCI_OPEN, dwFlags, Longint(@MyOpenParms));
// one could use mciSendCommand(DevId, here to specify a particular device
if MyError = 0 then
FDeviceID := MyOpenParms.wDeviceID
else
raise Exception.Create(Open Failed);
end;
function TForm1.GetStatus(StatusRequested: DWORD): Longint;
var
MyStatusParms: TMCI_Status_Parms;
begin
dwFlags := MCI_WAIT or MCI_STATUS_ITEM;
with MyStatusParms do
begin
dwCallback := Handle;
dwItem := StatusRequested;
end;
MyError := mciSendCommand(FDeviceID,
MCI_STATUS,
MCI_WAIT or MCI_STATUS_ITEM,
Longint(@MyStatusParms));
if MyError = 0 then
Result := MyStatusParms.dwReturn
else
raise Exception.Create(Status call to get status of +
IntToStr(StatusRequested) + Failed);
end;
procedure TForm1.CloseMedia;
var
MyGenParms: TMCI_Generic_Parms;
begin
if FDeviceID 0 then
begin
dwFlags := 0;
MyGenParms.dwCallback := Handle; // TForm1.Handle
MyError := mciSendCommand(FDeviceID, MCI_CLOSE, dwFlags, Longint(@MyGenParms));
if MyError = 0 then
FDeviceID := 0
else
begin
raise Exception.Create(Close Failed);
end;
end;
end;
//Example:
//Beispiel:
procedure TForm1.Button1Click(Sender: TObject);
begin
if OpenDialog1.Execute then
begin
OpenMedia(OpenDialog1.FileName);
with ListBox1.Items do
begin
Add(Average Bytes / Sec : + IntToStr(GetStatus(MCI_WAVE_STATUS_AVGBYTESPERSEC)));
Add(Bits / Sample : + IntToStr(GetStatus(MCI_WAVE_STATUS_BITSPERSAMPLE)));
Add(Samples / Sec : + IntToStr(GetStatus(MCI_WAVE_STATUS_SAMPLESPERSEC)));
Add(Channels : + IntToStr(GetStatus(MCI_WAVE_STATUS_CHANNELS)));
end;
CloseMedia;
end;
end;
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