IWMSBroadcastPublishingPoint.AnnounceToNSCStream (Visual Basic .NET)

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IWMSBroadcastPublishingPoint.AnnounceToNSCStream (Visual Basic .NET)

The AnnounceToNSCStream method retrieves an UCOMIStream object containing a file stream that can be used by a client to receive and render a broadcast.

  • Note   This method is available only on Windows Server 2003, Enterprise Edition; Windows Server 2003, Datacenter Edition; Windows Server 2008 Enterprise; and Windows Server 2008 Datacenter.

Syntax

  UCOMIStream = IWMSBroadcastPublishingPoint
  .AnnounceToNSCStream()

Parameters

This method takes no parameters.

Return Values

This method returns an UCOMIStream object containing the NSC file stream.

Remarks

Players cannot connect directly to a server to render a multicast stream. Therefore, to obtain the information required to receive a multicast broadcast, you must use the AnnounceToNSCStream or AnnounceToNSCFile method to provide players the necessary information. This stream contains a multicast address, a port number, a rollover URL, source content headers, and so on.

Before calling the AnnounceToNSCStream method, you must add the names of all of the media files included in the multicast to the IWMSAnnouncementStreamFormats object collection and call the IWMSBroadcastPublishingPoint.Announce method.

Example Code

Imports Microsoft.WindowsMediaServices.Interop
Imports System.Runtime.InteropServices

Private Sub GetAnnouncementStream()
Imports System.Runtime.InteropServices
Imports System.Text

    ' Declare variables.
    Dim Server As WMSServer
    Dim PubPoints As IWMSPublishingPoints
    Dim PubPoint As IWMSPublishingPoint
    Dim BCPubPoint As IWMSBroadcastPublishingPoint
    Dim Dec As Decoder = Encoding.UTF8.GetDecoder()
    Dim oStream As UCOMIStream
    Dim StreamStats As STATSTG
    Dim Bytes As Byte()
    Dim Chars As Char()
    Dim iChars As Integer
    Dim i As Integer

Try
    ' Create the WMSServer object.
    Server = New WMSServer()

    ' Retrieve the IWMSPublishingPoints object.
    PubPoints = Server.PublishingPoints

    ' Retrieve each publishing point and retrieve the
    ' IWMSBroadcastPublishingPoint object.
    For i = 0 To Server.PublishingPoints.Count – 1

        PubPoint = PubPoints.Item(i)
        If PubPoint.Type = _
        WMS_PUBLISHING_POINT_TYPE.WMS_PUBLISHING_POINT_TYPE_BROADCAST Then
            BCPubPoint = PubPoint
            Exit For
        End If
    Next i

    ' Retrieve the announcement stream that clients can use
    ' to connect to the publishing point.
    BCPubPoint.Announce()

    oStream = BCPubPoint.AnnounceToNSCStream()

    oStream.Stat(StreamStats, 0)

    Bytes = Array.CreateInstance(GetType(Byte), StreamStats.cbSize)
    oStream.Read(Bytes, StreamStats.cbSize, Nothing)
    iChars = Dec.GetCharCount(Bytes, 0, StreamStats.cbSize)
    Chars = Array.CreateInstance(GetType(Char), iChars)
    iChars = Dec.GetChars(Bytes, 0, StreamStats.cbSize, Chars, 0)

    Dim strBuf As String = New String(Chars, 0, StreamStats.cbSize)

Catch excCom As COMException
    ' TODO: Handle COM exceptions.
Catch exc As Exception
    ' TODO: Handle errors.
Finally
    ' TODO: Clean-up code goes here.
End Try

End Sub

Requirements

Reference: Add a reference to Microsoft.WindowsMediaServices.

Namespace: Microsoft.WindowsMediaServices.Interop.

Assembly: Microsoft.WindowsMediaServices.dll.

Library: WMSServerTypeLib.dll.

Platform: Windows Server 2003 family, Windows Server 2008 family.

See Also

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