MSVidWebDVD.KaraokeChannelContent Property

Article
01/07/2009

Note This topic applies to Windows XP Service Pack 1 or later.

The KaraokeChannelContent property retrieves a value that indicates the type of content in the specified karaoke channel in the specified stream.

VidWebDVD.KaraokeChannelContent(
   lStream As Long,
   lChan As Long
) As Long

Parameters

lStream
Long specifying the stream to check.
lChan
Long specifying the channel to check.

Return Value

Returns an integer value whose individual bits specify the contents of the karaoke channel. Returned values include the following.

Hexadecimal Value	Description
0x0001	Guide vocal 1
0x0002	Guide vocal 2
0x0004	Guide melody 1
0x0008	Guide melody 2
0x0010	Guide melody A
0x0020	Guide melody B
0x0040	Sound effect A
0x0080	Sound effect B

Error Codes

If the property fails, Err.Number may be set to one of the following values.

Value	Description
E_UNEXPECTED	Unspecified error.
VFW_E_DVD_INVALIDDOMAIN	You attempted to take the value in a domain that does not support this property.
E_NO_DVD_VOLUME	No DVD in the machine.
E_REGION_CHANGE_FAIL	The DVD has a different region than the player.
E_INVALIDARG	lStream is less than 0 or lChan is greater than 7.

Remarks

This property is read-only. DVD audio channel numbering is zero-based, so channels 2, 3, and 4 are the auxiliary karaoke channels. After the method returns, perform a bitwise AND operation on the return value to determine the contents of each channel. Because a single channel might have more than one type of content recorded on it, you should test for all the possible values even after a match is found.

The following code example demonstrates how to test the content of a stream's channel against each possible value:

iContent = VidWebDVD.KaraokeChannelContent(lStream, lChan)
' VB-style hex values.
If(iContent And &H1) Then   
     ' Set a check box or another UI control to 
     '  indicate this channel has the Guide Vocal 1.
End If
If(iContent And &H2) Then
     ' Set a check box or another UI control to 
    '  indicate this channel has the Guide Vocal 2.
 End If
If(iContent And &H4) Then
    ' Set a check box or another UI control to 
    '  indicate this channel has the Guide Melody 1.
 End If
 ' Repeat for each possible value for each channel.

After the user knows the contents of each channel, he or she must be able to adjust the volume or turn the individual channels on or off as needed. Implement this functionality in your application by using the KaraokeAudioPresentationMode property.

Note To play karaoke discs, the audio decoder on the user's system must be compatible with the DirectShow® 8 karaoke implementation.

Requirements

Type Library	Use MS Video Control 1.0 Type Library and Microsoft Tuner .10 Type Library.
DLL	Requires Quartz.dll.

Share via