Sound Help

[jignesh142]

i am trying make software which plays different frequency sound.My problem is that out of three sound first two plays very fast and third plays for longer time.The code for the program is below
can anybody help?

Option Explicit
'
' DirectSound access
Dim DX As DirectX8
Dim DS As DirectSound8
Dim dsToneBuffer As DirectSoundSecondaryBuffer8
Dim desc As DSBUFFERDESC
'
' Global variables
Const PI = 3.14159265358979
Const SRATE = 44100             ' Sampling Rate
Const DUR = 5                ' Tone duration
Const FREQUENCY = 240              ' Tone frequency
Dim sbuf(0 To DUR * SRATE) As Integer

Public Sub Command1_Click()
Dim sc(3) As Double
Static J As Integer
Dim FREQ As Integer


sc(1) = 1
sc(2) = 2
sc(3) = 2.5
For J = 1 To 3
FREQ = FREQUENCY * sc(J)
Call createtone(FREQ, DUR)
' play the tone
dsToneBuffer.Play DSBPLAY_DEFAULT
Next J

End Sub

Private Sub Form_Load()
'
' initialise DirectSound
Set DX = New DirectX8
Set DS = DX.DirectSoundCreate("")
DS.SetCooperativeLevel Me.hWnd, DSSCL_NORMAL
'
' create a buffer
desc.fxFormat.nFormatTag = WAVE_FORMAT_PCM
desc.fxFormat.nSize = 0
desc.fxFormat.lExtra = 0
desc.fxFormat.nChannels = 1
desc.fxFormat.lSamplesPerSec = SRATE
desc.fxFormat.nBitsPerSample = 16
desc.fxFormat.nBlockAlign = 2
desc.fxFormat.lAvgBytesPerSec = 2 * SRATE
desc.lFlags = 0
desc.lBufferBytes = 2 * DUR * SRATE
Set dsToneBuffer = DS.CreateSoundBuffer(desc)
End Sub
Public Sub createtone(FREQ As Integer, DUR As Integer)

' create a tone
Dim I
For I = 0 To DUR * SRATE
    sbuf(I) = 10000 * Sin(2 * PI * FREQ * I / SRATE)
Next I
'
' copy tone to buffer
dsToneBuffer.WriteBuffer 0, 2 * DUR * SRATE, sbuf(0), DSBLOCK_DEFAULT


'
End Sub

[WindozeNT]

This revised code will play all 3 tones at roughly the same speed:

Option Explicit

' DirectSound access
Dim DX As DirectX8
Dim DS As DirectSound8
Dim dsToneBuffer As DirectSoundSecondaryBuffer8
Dim desc As DSBUFFERDESC

' Global variables
Const PI = 3.14159265358979
Const SRATE = 44100             ' Sampling Rate
Const DUR = 5                ' Tone duration
Const FREQUENCY = 240              ' Tone frequency
Dim sbuf() As Integer

Public Sub Command1_Click()
Dim sc(4) As Double
Static J As Integer
Dim FREQ As Integer

sc(1) = 1
sc(2) = 2
sc(3) = 2.5

For J = 1 To 4
 ReDim sbuf(0 To (DUR * J) * SRATE)
 FREQ = FREQUENCY * sc(J)
 Call createtone(FREQ, DUR, J)
 dsToneBuffer.Play DSBPLAY_DEFAULT ' play the tone
Next J

DoEvents
dsToneBuffer.Stop
End Sub

Private Sub Form_Load()
' initialise DirectSound
Set DX = New DirectX8
Set DS = DX.DirectSoundCreate("")
DS.SetCooperativeLevel Me.hWnd, DSSCL_NORMAL

' create a buffer
desc.fxFormat.nFormatTag = WAVE_FORMAT_PCM
desc.fxFormat.nSize = 0
desc.fxFormat.lExtra = 0
desc.fxFormat.nChannels = 1
desc.fxFormat.lSamplesPerSec = SRATE
desc.fxFormat.nBitsPerSample = 16
desc.fxFormat.nBlockAlign = 2
desc.fxFormat.lAvgBytesPerSec = 2 * SRATE
desc.lFlags = 0
desc.lBufferBytes = 2 * (DUR * 4) * SRATE
Set dsToneBuffer = DS.CreateSoundBuffer(desc)
End Sub

Public Sub createtone(FREQ As Integer, DUR As Integer, CV As Integer)
' create a tone
Dim I
For I = 0 To (DUR * CV) * SRATE
    sbuf(I) = 10000 * Sin(2 * PI * FREQ * I / SRATE)
Next I

' copy tone to buffer
dsToneBuffer.WriteBuffer 0, 2 * (DUR * CV) * SRATE, sbuf(0), DSBLOCK_DEFAULT
End Sub

What I did was I converted sbuf to a dynamic array and resized it when a new tone played. The tone buffer length is changed to the value of DUR times the current index of the tone being played (represented as J in the For loop and as CV in the function). Although there are 3 tones being played, the buffer is resized for 4, with the 4th buffer being reserved for a null tone (keeping tone 3 from being longer than the others; notice that I didn't set sc(4)?) then after the For loop is done I told DirectSound to stop playing. However, it seems that after 10 plays, DirectX glitches out and skips over the first tone after each subsequent play starting at 11 plays.
Hope this helps!