Code:
var
msSound: TMemoryStream;
procedure MakeSound(Frequency{Hz}, Duration{mSec}: Integer; Volume: TVolumeLevel);
{writes tone to memory and plays it}
var
WaveFormatEx: TWaveFormatEx;
i, TempInt, DataCount, RiffCount: integer;
SoundValue: byte;
w: double; // omega ( 2 * pi * frequency)
const
Mono: Word = $0001;
// SampleRate: Integer = 11025; // 8000, 11025, 22050, or 44100
SampleRate: Integer = 44100;
RiffId: string = 'RIFF';
WaveId: string = 'WAVE';
FmtId: string = 'fmt ';
DataId: string = 'data';
begin
// sndPlaySound (nil, 0);
if Frequency > (0.6 * SampleRate) then
begin
ShowMessage(Format('Sample rate of %d is too Low to play a tone of %dHz',
[SampleRate, Frequency]));
Exit;
end;
with WaveFormatEx do
begin
wFormatTag := WAVE_FORMAT_PCM;
nChannels := Mono;
nSamplesPerSec := SampleRate;
wBitsPerSample := $0008;
nBlockAlign := (nChannels * wBitsPerSample) div 8;
nAvgBytesPerSec := nSamplesPerSec * nBlockAlign;
cbSize := 0;
end;
if msSound = nil
then msSound := TMemoryStream.Create
else msSound.Clear;
with msSound do
begin
{Calculate length of sound data and of file data}
DataCount := (Duration * SampleRate) div 1000; // sound data
RiffCount := Length(WaveId) + Length(FmtId) + SizeOf(DWORD) +
SizeOf(TWaveFormatEx) + Length(DataId) + SizeOf(DWORD) + DataCount; // file data
{write out the wave header}
Write(RiffId[1], 4); // 'RIFF'
Write(RiffCount, SizeOf(DWORD)); // file data size
Write(WaveId[1], Length(WaveId)); // 'WAVE'
Write(FmtId[1], Length(FmtId)); // 'fmt '
TempInt := SizeOf(TWaveFormatEx);
Write(TempInt, SizeOf(DWORD)); // TWaveFormat data size
Write(WaveFormatEx, SizeOf(TWaveFormatEx)); // WaveFormatEx record
Write(DataId[1], Length(DataId)); // 'data'
Write(DataCount, SizeOf(DWORD)); // sound data size
{calculate and write out the tone signal} // now the data values
w := 2 * Pi * Frequency; // omega
for i := 0 to DataCount - 1 do
begin
SoundValue := 127 + trunc(Volume * sin(i * w / SampleRate)); // wt = w * i / SampleRate
Write(SoundValue, SizeOf(Byte));
end;
{now play the sound}
//sndPlaySound (nil, 0);
sndPlaySound(msSound.Memory, SND_MEMORY or SND_ASYNC);
end;
end;
procedure TForm1.Button2Click(Sender: TObject);
var i : integer;
begin
for i := 0 to 100 do
begin
MakeSound (1000 + 100 * round (5*random), 150, 100);
Application.ProcessMessages;
sleep (150);
end;
end;
var
msSound: TMemoryStream;
procedure MakeSound(Frequency{Hz}, Duration{mSec}: Integer; Volume: TVolumeLevel);
{writes tone to memory and plays it}
var
WaveFormatEx: TWaveFormatEx;
i, TempInt, DataCount, RiffCount: integer;
SoundValue: byte;
w: double; // omega ( 2 * pi * frequency)
const
Mono: Word = $0001;
// SampleRate: Integer = 11025; // 8000, 11025, 22050, or 44100
SampleRate: Integer = 44100;
RiffId: string = 'RIFF';
WaveId: string = 'WAVE';
FmtId: string = 'fmt ';
DataId: string = 'data';
begin
// sndPlaySound (nil, 0);
if Frequency > (0.6 * SampleRate) then
begin
ShowMessage(Format('Sample rate of %d is too Low to play a tone of %dHz',
[SampleRate, Frequency]));
Exit;
end;
with WaveFormatEx do
begin
wFormatTag := WAVE_FORMAT_PCM;
nChannels := Mono;
nSamplesPerSec := SampleRate;
wBitsPerSample := $0008;
nBlockAlign := (nChannels * wBitsPerSample) div 8;
nAvgBytesPerSec := nSamplesPerSec * nBlockAlign;
cbSize := 0;
end;
if msSound = nil
then msSound := TMemoryStream.Create
else msSound.Clear;
with msSound do
begin
{Calculate length of sound data and of file data}
DataCount := (Duration * SampleRate) div 1000; // sound data
RiffCount := Length(WaveId) + Length(FmtId) + SizeOf(DWORD) +
SizeOf(TWaveFormatEx) + Length(DataId) + SizeOf(DWORD) + DataCount; // file data
{write out the wave header}
Write(RiffId[1], 4); // 'RIFF'
Write(RiffCount, SizeOf(DWORD)); // file data size
Write(WaveId[1], Length(WaveId)); // 'WAVE'
Write(FmtId[1], Length(FmtId)); // 'fmt '
TempInt := SizeOf(TWaveFormatEx);
Write(TempInt, SizeOf(DWORD)); // TWaveFormat data size
Write(WaveFormatEx, SizeOf(TWaveFormatEx)); // WaveFormatEx record
Write(DataId[1], Length(DataId)); // 'data'
Write(DataCount, SizeOf(DWORD)); // sound data size
{calculate and write out the tone signal} // now the data values
w := 2 * Pi * Frequency; // omega
for i := 0 to DataCount - 1 do
begin
SoundValue := 127 + trunc(Volume * sin(i * w / SampleRate)); // wt = w * i / SampleRate
Write(SoundValue, SizeOf(Byte));
end;
{now play the sound}
//sndPlaySound (nil, 0);
sndPlaySound(msSound.Memory, SND_MEMORY or SND_ASYNC);
end;
end;
procedure TForm1.Button2Click(Sender: TObject);
var i : integer;
begin
for i := 0 to 100 do
begin
MakeSound (1000 + 100 * round (5*random), 150, 100);
Application.ProcessMessages;
sleep (150);
end;
end;
Naravno, ne znam unapred koji ce biti sledeci zvuk, ni koliko ce trajati!