IWMEncDeviceControlPlugin.StartupLatency

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The StartupLatency property specifies and retrieves the number of frames to play before encoding.

Syntax

IWMEncDeviceControlPlugin.StartupLatency = Long
Long = IWMEncDeviceControlPlugin.StartupLatency

Parameters

This property takes no parameters.

Property Value

A Long that indicates the startup latency value in frames.

Remarks

The StartupLatency property is used to offset the delay between issuing the command to start encoding and when encoding actually begins. You will have to experiment with your system to determine its latency in frames. After you determine the length of that delay in frames, you can start the encoder early, relative to your mark-in point, by that number of frames.

To control digital devices programmatically, you must add the Windows Media Encoder Device Control reference to the project. For more information, see Programming in Visual Basic.

Example Code

' Create a WMEncoder object.
  Dim Encoder As WMEncoder
  Set Encoder = New WMEncoder

' Add the device as the audio source and the video source.
  Dim SrcGrpColl As IWMEncSourceGroupCollection
  Dim SrcGrp As IWMEncSourceGroup2
  Dim SrcAud As IWMEncSource
  Dim SrcVid As IWMEncVideoSource
  Set SrcGrpColl = Encoder.SourceGroupCollection
  Set SrcGrp = SrcGrpColl.Add("SG_1")
  Set SrcAud = SrcGrp.AddSource(WMENC_AUDIO)
  Set SrcVid = SrcGrp.AddSource(WMENC_VIDEO)
  ' Replace the following name with the name of your device.
  SrcAud.SetInput ("Device://Device resource name")
  SrcVid.SetInput ("Device://Device resource name")

' Configure the output and profile.

' Retrieve the device control collection, then add a device to it.
  Dim DCColl As IWMEncDeviceControlCollection
  Set DCColl = SrcGrp.DeviceControlCollection
  Dim DControl As IWMEncDeviceControl
  Set DControl = DCColl.Add
  ' Replace the following name with the name of your device.
  DControl.SetInput ("DeviceControl://Device resource name")

' Initialize the encoding session.
  Encoder.PrepareToEncode True

' Get the plug-in from the device.
  Dim DCPlugin As IWMEncDeviceControlPlugin
  Set DCPlugin = DControl.GetDeviceControlPlugin

' Specify latency settings.
  DCPlugin.StartupLatency = 2
  DCPlugin.StopLatency = 3

Requirements

Reference: Windows Media Encoder Device Control

Library: wmdevctl.dll

See Also