VB6.0 – Sound and DirectXSound Tutorial

[CVMichael]

Splitting a Stereo buffer to 2 Mono buffers

In a Stereo buffer, the left channel is stored first, then the right channel.
So, at position 1, you will find the sample of the left channel, position 2 is right channel, position 3 is left channel again, and so on.

Here is code to split Stereo buffer to 2 Mono buffers, for 8 and 16 Bit:

Public Sub SoundStereoToMono16(InStereo() As Integer, OutLeftChannel() As Integer, OutRightChannel() As Integer)
    Dim InPos As Long
    Dim OutPos As Long
    
    ReDim OutLeftChannel((UBound(InStereo) + 1) \ 2 - 1)
    ReDim OutRightChannel(UBound(OutLeftChannel))
    
    For InPos = 0 To UBound(InStereo) Step 2
        OutLeftChannel(OutPos) = InStereo(InPos)
        OutRightChannel(OutPos) = InStereo(InPos + 1)
        
        OutPos = OutPos + 1
    Next InPos
End Sub
 
Public Sub SoundStereoToMono8(InStereo() As Byte, OutLeftChannel() As Byte, OutRightChannel() As Byte)
    Dim InPos As Long
    Dim OutPos As Long
    
    ReDim OutLeftChannel((UBound(InStereo) + 1) \ 2 - 1)
    ReDim OutRightChannel(UBound(OutLeftChannel))
    
    For InPos = 0 To UBound(InStereo) Step 2
        OutLeftChannel(OutPos) = InStereo(InPos)
        OutRightChannel(OutPos) = InStereo(InPos + 1)
        
        OutPos = OutPos + 1
    Next InPos
End Sub