Reducing Switching Latency
The WMS Network Data Source plug-in does not allow the server to cue up a stream from a network source such as an encoder or a distribution server. Therefore, switching latencies occur when the server uses this plug-in and switches between streams in either of the two following cases.
The server switches from an on-demand source to a network source that is directly referenced in the playlist.
<?wsx version="1.0"?> <smil> <media src="c:\wmpub\wmroot\Ad_1.wmv"/> <media src="http://encoder_1:8080"/> </smil>The server switches from one network source to another, and both sources are directly referenced in the playlist.
<?wsx version="1.0"?> <smil> <media src = "http://encoder_1:8080" dur = "5min"/> <media src = "http://encoder_2:8080" dur = "5min"/> </smil>
To reduce switching latency, you can associate each network source with a running broadcast publishing point. For example, if you create a publishing point named LiveSource, set its path to http://encoder_1:8080, and start it, the following playlist will switch seamlessly between the live feed from the publishing point and an on-demand stream.
<?wsx version="1.0"?>
<smil>
<media src="c:\wmpub\wmroot\Ad_1.wmv" dur="5min"/>
<media src="lpp://LiveSource" dur="5min"/>
</smil>
Note
In the preceding example, the lpp scheme type identifies a local publishing point named LiveSource. The encoder that is providing the live feed is not directly referenced. You must start the publishing point before your playlist can switch to it.