Share via

IWMSTransportProperties::GetStreamProperties

  • Article

banner art

Previous Next

IWMSTransportProperties::GetStreamProperties

The GetStreamProperties method retrieves properties of a stream.

  • **Note   **This method is available only on Windows Server 2003, Enterprise Edition with Service Pack 1; Windows Server 2003, Datacenter Edition with Service Pack 1; and Windows Server 2008.

Syntax

  HRESULT GetStreamProperties(
  DWORD  dwStreamId,
  DWORD  dwAlternateIndex,
  IWMSContext**  ppProps
);

Parameters

dwStreamId

[in]  DWORD containing the stream ID of the stream.

dwAlternateIndex

[in]  DWORD containing the unique alternate index of the stream.

ppProps

[out]  Pointer to a pointer to an IWMSContext interface containing the properties of the stream.

Return Values

If the method succeeds, it returns S_OK. If it fails, it returns an HRESULT error code.

Remarks

If you are using RTSP to stream content, you can retrieve the UDP port number of a connected client. To retrieve this value, you must create a custom event notification plug-in that accesses the RTSP SETUP request sent by the client during the initial setup process. You can then use GetStreamProperties to retrieve a pointer to an IWMSContext interface that contains the transport settings that were defined in the SETUP request.

Example Code

The following example shows how to retrieve the UDP port number of a connected client through the use of a user-defined method. Add WMS_EVENT_SELECT_STREAMS to the list of handled events for your plug-in and call this user-defined method within the IWMSEventNotificationPlugin::OnEvent method.

HRESULT CCustomEventPlugin::GetPortNumber(
                                         IWMSCommandContext, *pCommandCtx)
{
    // Declare variables.
    DWORD                             cDescCount = 0;
    DWORD                             dwStreamId = -1;
    DWORD                             dwPortNumber;
    HRESULT                           hr = S_OK;
    IWMSContext                       *pCommandRequest = NULL;
    IWMSStreamSwitchDescriptionList   *pStrmSwitchDesc = NULL;
    IWMSTransportProperties           *pTransProp = NULL;

    // Retrieve a pointer to the command request context.
    hr = pCommandCtx->GetCommandRequest(&pCommandRequest);

    // Retrieve a pointer to an IWMSStreamSwitchDescriptionList interface.
    hr = pCommandRequest->GetAndQueryIUnknownValue(
                                     WMS_COMMAND_CONTEXT_STREAM_SWITCH,
                                     WMS_COMMAND_CONTEXT_STREAM_SWITCH_ID,
                                     IID_IWMSStreamSwitchDescriptionList,
                                     (IUnknown **)&pStrmSwitchDesc,
                                     0);
    if (FAILED (hr)) goto EXIT;

    // Retrieve the number of stream descriptions in the stream 
    // descriptions list.
    hr = pStrmSwitchDesc->GetDescriptionCount(&cDescCount);

    // After the correct stream is found, retrieve the new stream number 
    // for that stream.
    for (DWORD i = 0; i < cDescCount; i++)
    {
        CWMSStreamSwitch objStreamSwitch;
        ZeroMemory(&objStreamSwitch, sizeof(CWMSStreamSwitch));

        hr = pStrmSwitchDesc->GetIndexedDescription(i, &objStreamSwitch);

        if (SUCCEEDED (hr))
        {
            if ((objStreamSwitch.ModifierType == WMS_NO_MODIFIER) || 
               ((objStreamSwitch.ModifierType == WMS_THINNING_MODIFIER) &&
               ((objStreamSwitch.dwModifier == WMS_NO_THINNING) || 
               (objStreamSwitch.dwModifier == 
                                       WMS_INTERMEDIATE_FRAME_THINNING))))
            {
                dwStreamId = objStreamSwitch.dwNewStreamNumber;
                break;
            }
        }
    }

    // Retrieve a pointer to an IWMSTransportProperties interface.
    hr = pContext->GetAndQueryIUnknownValue(
                                         WMS_COMMAND_CONTEXT_TRANSPORT,
                                         WMS_COMMAND_CONTEXT_TRANSPORT_ID,
                                         IID_IWMSTransportProperties,
                                         (IUnknown **)&pTransProp, 
                                         0);
    if (FAILED (hr)) goto EXIT;

    // Use the new stream number to retrieve the UDP port number through 
    // the stream properties.
    if (dwStreamId != -1)
    {
        IWMSContext * pTransportCtx = NULL;
        hr = pTransProp->GetStreamProperties(dwStreamId,
                                             0,
                                             &pTransportCtx);

        if (SUCCEEDED (hr) )
        {
            // Retrieve the UDP port number of the client.
            hr = pTransportCtx->GetLongValue(
                                     WMS_TRANSPORT_CONTEXT_CLIENT_PORT,
                                     WMS_TRANSPORT_CONTEXT_CLIENT_PORT_ID,
                                     (LONG *)&dwPortNumber,
                                     0);
        }
        else
        {
            goto EXIT;
        }
    }

    EXIT:
    // TODO: Release temporary COM objects.

    return( hr );
}

Requirements

Library: WMSServerTypeLib.dll.

Platform: Windows Server 2003, Enterprise Edition with Service Pack 1; Windows Server 2003, Datacenter Edition with Service Pack 1; Windows Server 2008..

See Also

Previous Next