SpAudioFormat GetWaveFormatEx method (SAPI 5.3)

Microsoft Speech API 5.3

Object: SpAudioFormat
Type: Hidden

GetWaveFormatEx Method

The GetWaveFormatEx method gets the audio format as an SpWaveFormatEx object.

Non-standard formats using wav files should use GetWaveFormatEx to retrieve formats.

  
    SpAudioFormat.GetWaveFormatEx() As SpWaveFormatEx

Parameters

None.

Return Value

The GetWaveFormatEx method returns an SpWaveFormatEx variable.

Example

The following Visual Basic form code demonstrates the use of the GetWaveFormatEx and SetWaveFormatEx properties. To run this code, create a form with the following controls:

• Two command buttons called Command1 and Command2

Paste this code into the Declarations section of the form.

The Command1 procedure creates an SpAudioFormat object and sets it to the audio format SAFT22kHz16BitStereo. It then gets the format object's SpWaveFormatEx object and displays the properties. The code then changes the format of the SpAudioFormat object to SAFT11kHz16BitMono, gets a new SpWaveFormatEx object and displays its properties again. Note that the SpWaveFormatEx properties have changed to reflect the new audio format.

The Command2 procedure creates an SpAudioFormat object and sets it to the audio format SAFT22kHz16BitStereo. It then gets the format object's SpWaveFormatEx object and displays the properties. The code then changes the properties of the SpWaveFormatEx object to match the SAFT11kHz16BitMono format and sets the format of the SpAudioFormat object with the SetWaveFormatEx method. Note that the SpAudioFormat object's Type property has changed to SAFT11kHz16BitMono to reflect the new SpWaveFormatEx properties.

  
Option Explicit

Dim F As SpeechLib.SpAudioFormat
Dim W As SpeechLib.SpWaveFormatEx

Private Sub Command1_Click()
    On Error GoTo EH

    'Create an empty SpAudioFormat object
    'Set it to the default format
    'Get its format in an SpWaveFormatEx object
    Set F = New SpAudioFormat
    F.Type = SAFT22kHz16BitStereo
    Set W = F.GetWaveFormatEx

    Debug.Print
    Debug.Print "Default SpAudioFormat and SpWaveFormatEx"
    Debug.Print "Format:        SAFT22kHz16BitStereo"
    Debug.Print "Format code:   " & F.Type
    Debug.Print "AvgBytesPerSec " & W.AvgBytesPerSec
    Debug.Print "BitsPerSample  " & W.BitsPerSample
    Debug.Print "BlockAlign     " & W.BlockAlign
    Debug.Print "Channels       " & W.Channels
    Debug.Print "ExtraData      " & W.ExtraData
    Debug.Print "FormatTag      " & W.FormatTag
    Debug.Print "SamplesPerSec  " & W.SamplesPerSec

    'Give the SpAudioFormat object an audio type
    'Get its format in an SpWaveFormatEx object
    F.Type = SAFT11kHz16BitMono
    Set W = F.GetWaveFormatEx

    Debug.Print
    Debug.Print "Changing SpAudioFormat changes SpWaveFormatEx"
    Debug.Print "Format:        SAFT11kHz16BitMono"
    Debug.Print "Format code:   " & F.Type
    Debug.Print "AvgBytesPerSec " & W.AvgBytesPerSec
    Debug.Print "BitsPerSample  " & W.BitsPerSample
    Debug.Print "BlockAlign     " & W.BlockAlign
    Debug.Print "Channels       " & W.Channels
    Debug.Print "ExtraData      " & W.ExtraData
    Debug.Print "FormatTag      " & W.FormatTag
    Debug.Print "SamplesPerSec  " & W.SamplesPerSec

EH:
    If Err.Number Then ShowErrMsg
End Sub

Private Sub Command2_Click()
    On Error GoTo EH

    'Create an empty SpAudioFormat object
    'Set it to the default format
    'Get its format in an SpWaveFormatEx object

    Set F = New SpAudioFormat
    F.Type = SAFT22kHz16BitStereo
    Set W = F.GetWaveFormatEx

    Debug.Print
    Debug.Print "Default SpAudioFormat and SpWaveFormatEx:"
    Debug.Print "Format:        SAFT22kHz16BitStereo"
    Debug.Print "Format code:   " & F.Type
    Debug.Print "AvgBytesPerSec " & W.AvgBytesPerSec
    Debug.Print "BitsPerSample  " & W.BitsPerSample
    Debug.Print "BlockAlign     " & W.BlockAlign
    Debug.Print "Channels       " & W.Channels
    Debug.Print "ExtraData      " & W.ExtraData
    Debug.Print "FormatTag      " & W.FormatTag
    Debug.Print "SamplesPerSec  " & W.SamplesPerSec

    'Set SpWaveFormatEx properties as in SAFT11kHz16BitMono format;
    'this will reset the SpAudioFormat Type.

    Debug.Print
    Debug.Print "Changing SpWaveFormatEx properties changes SpAudioFormat:"
    W.AvgBytesPerSec = 22050
    W.BitsPerSample = 16
    W.BlockAlign = 2
    W.Channels = 1
    W.SamplesPerSec = 11025

    Call F.SetWaveFormatEx(W)
    Debug.Print "Format code:   " & F.Type

EH:
    If Err.Number Then ShowErrMsg
End Sub

Private Sub ShowErrMsg()

    ' Declare identifiers:
    Dim T As String

    T = "Desc: " & Err.Description & vbNewLine
    T = T & "Err #: " & Err.Number
    MsgBox T, vbExclamation, "Run-Time Error"
    End

End Sub