Streaming DS directly from memory - Xtreme Visual Basic Talk

02-26-2006, 11:34 PM

VirgilFox

Newcomer

Join Date: Feb 2006

Location: Auckland

Posts: 1

Streaming DS directly from memory

I've downloaded sample code for directsound which demonstrates loading a DS buffer from a wave or loading from a resource - even streaming from a file, but is it possible to stream directly from an array in memory?

I'm generating sound samples in real time. I want to send them directly to a streaming DS buffer.

Thanks.

03-02-2006, 04:32 AM

Leade

Junior Contributor

Join Date: Jul 2005

Location: Wherever i fall over

Posts: 222

Stream from a buffer.

Quote:

Originally Posted by VirgilFox

I am on fire today.

If you want to stream from memory then you have to create the buffer from scratch. use the create function to make the buffer you must know the parameters for the buffer or it will fail. Then you just play it in the normal way.

you can erase the buffer once it has be created.

Leade

Code:

Option Explicit
Private Const WaveFormat = DxVBLibA.WAVE_FORMAT_PCM
Private Format As DxVBLibA.WAVEFORMATEX

Private Type SecondaryBufferDetails
    SoundBuffer As DxVBLibA.DirectSoundSecondaryBuffer8
    SoundDescription As DxVBLibA.DSBUFFERDESC
    SoundCursor As DxVBLibA.DSCURSORS
    BufferStatus As DxVBLibA.CONST_DSBSTATUSFLAGS
End Type
Private SoundData As SecondaryBufferDetails

'Creation
Public Function Create(ByRef Dx8Sound As DxVBLibA.DirectSound8, BytesPerSec As Long, Extra As Long, _
                                SamplesPerSec As Long, BitsPerSample As Integer, _
                                BlockAlign As Integer, Channels As Integer, _
                                FormatTag As Integer, Size As Integer, BufferBytes As Long, _
                                ByRef Data() As Byte, Optional Offset As Long = 0)
                                
    'First we must set the format
    With SoundData.SoundDescription
        .fxFormat.lAvgBytesPerSec = BytesPerSec
        .fxFormat.lExtra = Extra
        .fxFormat.lSamplesPerSec = SamplesPerSec
        .fxFormat.nBitsPerSample = BitsPerSample
        .fxFormat.nBlockAlign = BlockAlign
        .fxFormat.nChannels = Channels
        .fxFormat.nFormatTag = FormatTag
        .fxFormat.nSize = Size
        Format = .fxFormat
        .guid3DAlgorithm = ""
        .lFlags = DSBCAPS_LOCDEFER Or DSBCAPS_CTRLFREQUENCY Or DSBCAPS_CTRLPAN Or DSBCAPS_CTRLVOLUME Or DSBCAPS_CTRLPOSITIONNOTIFY Or DSBCAPS_STATIC  'Or DSBCAPS_CTRLFX
        .lBufferBytes = BufferBytes
    End With
    
    'Now we must create a sound buffer
    With SoundData
        Set .SoundBuffer = Nothing
        Set .SoundBuffer = Dx8Sound.CreateSoundBuffer(.SoundDescription)
    End With
    
    'Now read the wave data from the byte array
    'SoundData.SoundBuffer.WriteBuffer 0, 0, Data(Offset), DSBLOCK_ENTIREBUFFER
    SoundData.SoundBuffer.WriteBuffer 0, BufferBytes, Data(Offset), DSBLOCK_ENTIREBUFFER
    SoundData.SoundBuffer.SetCurrentPosition 1
    
End Function

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