[URGENT] Change Left/Right/Stereo Audio Channels?

Does anybody know how to switch audio channels of a video clip?

I'm currently using the "AxWindowsMediaPlayer" object to play video clips in my program, but i guess it doesn't support audio-channel controls?

Someone please help me! Thanks so much!

Anyone knows how? @"@

I just searched around on the internet...seems like there may be 3 different approaches to achieve this (I may be wrong tho):

1. Use something called "MCI"
2. Do nothing with the media player, but modify the system audio streams directly (for example, to enable right-channel audio -> discard the left channel and make a copy of the right channel to the left)
3 Use objects other than "AxWindowsMediaPlayer"

The funny thing is.. I dunno how any of these 3 approaches works!! -_-"

Maybe DirectX, but I don't have any Net examples.

hmmm...this is what i have:

VB Code:

Public Declare Function mciSendString Lib "winmm.dll" Alias "mciSendStringA" (ByVal lpstrCommand As String, ByVal lpstrReturnString As String, ByVal uReturnLength As UInt32, ByVal hwndCallback As UInt32) As UInt32
Dim RefInt As Long
  RefInt = mciSendString("setaudio NOWMUSIC source to right", vbNull, 0, 0)

But that doesn't work. (btw it gives it gives me "ReffInt=261" when i run the mciSendString line of code)

I guess i can't use mciSendString to control a AxWindowsMediaPlayer object. Damn...

Again, I wrote this class:

VB Code:

Imports System
Imports DxVBLibA
 
Public Class Soundplayer
 
    Private Declare Function mciSendString Lib "Winmm.dll" Alias "mciSendStringA" _
(ByVal lpstrCommand As String, ByVal lpstrReturnString As String, _
ByVal uReturnLength As System.UInt32, ByVal hwndCallback As System.UInt32) As System.UInt32
 
    Private File As String
 
    Private m_dx As New DirectX8
    Private m_ds As DirectSound8
 
 
    Public Sub New(ByVal strFileName As String)
 
        Me.File = strFileName
 
    End Sub
 
    ' To show what file is selected (if needed)
    Public ReadOnly Property FileName() As String
 
        Get
            Return File
        End Get
 
    End Property
 
    Public Function PlaySound() As Boolean
 
        If InitAudio() = True Then
            If PlayFile() = True Then
                Return True
            Else
                Return False
            End If
        Else
            ' Audiohardware not found
            ' exit here
            Return False
        End If
 
    End Function
 
    Public Function StopSound() As Boolean
 
        StopFile()
 
    End Function
 
    Private Function PlayFile() As Boolean
 
        Dim lRet As Long
 
        Try
            StopFile()
            lRet = mciSendString("open " & Me.File & " alias track", "", 0, 0)
            lRet = mciSendString("play track", "", 0, 0)
            PlayFile = (lRet = 0)
 
        Catch ex As Exception
            Return False
        End Try
 
        Return True
 
    End Function
 
    Public Sub CloseAudio()
        mciSendString("close all", 0, 0, 0)
    End Sub
 
    Private Function StopFile() As Boolean
 
        Dim lRet As Long
 
        Try
            lRet = mciSendString("stop track", "", 0, 0)
            lRet = mciSendString("close track", "", 0, 0)
            Return True
        Catch ex As Exception
            Return False
        End Try
 
    End Function
 
    Private Function InitAudio() As Boolean
 
        m_ds = m_dx.DirectSoundCreate("")
        If Err.Number <> 0 Then
            Return False
        Else
            Return True
        End If
 
    End Function
End Class

and have this in my Form1:

VB Code:

Public Class Form1
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
            Dim Sound As New Soundplayer(OpenFileDialog1.FileName)
            Sound.PlaySound()
        End If
    End Sub
End Class

I still get NO SOUND when opening a midi or mp3 file in Form1!!


Note:
1. When debugging, I got lRet=263 in the PlaySound() function. I know as long as IRet is not 0, the operation is unsuccessful. But what does "263" mean?
2. I added a reference to DirectX8 COM
3. I'm using Visual Studio 2005

could ANYONE plz help me?! -_-"

Use DirectX's DirectShow instead. It gives you total control over your media. I have the source code, and it was pretty easy to convert to .NET. Here's the source code:

http://www.vbforums.com/showpost.php...84&postcount=2

I don't have VS.NET in front of me, but one of the objects I believe was Quartz something. I forgot.

If u want, u can refer to this for the sample code I found on google (actually it's on codeproject.com)

http://66.102.7.104/search?q=cache:r..._zh-TW|lang_en

As you can tell..i modified the function declaration a bit coz when i use "Long" type, I get an unbalanced stack. Anyhow, I still find this error really odd...since the sample code says it's for "VB .Net". I suppose VB. Net code is a bit different from VB 2005 code?

Quote:

---

Originally Posted by Jacob Roman

Use DirectX's DirectShow instead. It gives you total control over your media. I have the source code, and it was pretty easy to convert to .NET. Here's the source code:

http://www.vbforums.com/showpost.php...84&postcount=2

I don't have VS.NET in front of me, but one of the objects I believe was Quartz something. I forgot.

---

Thx. I quickly read through your code. Seems like there's no controls for changing audio channels?

I didn't add everything in that code. I'm sure there's a way somewhere. ;)

I just tried the example in the following link:

http://www.vbforums.com/showthread.p...=mcisendstring

(i.e. the third post by wldrumstcs)

Somehow my compiler can't recognize:

VB Code:

Dim Id3 As New Id3() 
' can't recognize the Id3() object

also

VB Code:

MsgBox("There was an error trying to play " & GetLastBackSlash(MP3File) & ".", MsgBoxStyle.Critical, "Error!") 
'can't recognize the GetLastBackSlash() function