Controlling multicast client buffer behavior with URL modifiers

Windows Media Player 9 Series or later contains improvements that add efficiencies to the network connection process and minimize startup latency. This allows you to add a URL modifier that specifies the minimum buffer time to the path of a multicast stream. The URL modifier specifies a value for the Network Buffer Time property. The property value is the amount of time in milliseconds (ms) that the Player will buffer before playing the multicast stream. To specify the minimum buffer time for a multicast, add the following modifier to the multicast information (.nsc) file URL:

?WMBufferTime=Value

For example, the following multicast URL uses a modifier that sets buffer time to 500 ms.

http://WebServer/Channel1.nsc?WMBufferTime=500

Note

• You can also control multicast client buffer behavior by adding a Network Buffer Time property value below the Cache Expiration Time property in the multicast information file. For example, you can open the file in a text editor, such as Notepad, and then type the following:

  Network Buffer Time=0x000001F4
  
  

  In this example, 0x000001F4 is a hexadecimal value that sets the buffer time to 500 ms.

• Multicast stream cannot be accelerated. Therefore, if the WMBufferTime modifier or Network Buffer Time property values are set to a very low value, the buffer time may not be adequate to handle poor network conditions. Clients may have a poor playback experience as a result.

Related topics

• About multicast information files
• Controlling streaming behavior with URL modifiers