The basic structure of the SMIL file body consists of <stream> and <playlist> statements.

Stream Element

The <stream> element defines one or more virtual stream names that the playlists will feed into:

<stream name="playlist-high"></stream>
<stream name="playlist-low"></stream>

In this example, I have a high and low bandwidth stream. In your player, you reference the stream name, rather than the streamshedule.smil file, like this:

Flash RTMP:

streamer: rtmp://server.address(:port)/live
file: playlist-high

Flash HTTP:

http://server.address/live/playlist-high/manifest.f4m

HLS:

http://server.address/live/playlist-high/playlist.m3u8

Silverlight

http://server.address/live/playlist-high/Manifest

Playlist element

The <playlist> element defines specific video sequences that go into the virtual stream. There are four key parameters to the playlist element:

  • name : This is a unique name for that particular sequence.
  • playOnStream : This tells the Stream Class module which of the previously defined streams this playlist is associated with.
  • repeat : Valid values are true/false. This defines whether this playlist loops when it gets to the end.
  • scheduled : When this playlist is scheduled, in the format “YYYY-MM-DD HH:MM:SS” (24-hour time)

Within the playlist element are one or more <video> statements that use the following parameters:

  • src: the video to be played. Can either be:
  • a stream within the same live application (use the stream name only)
  • an MP4 video file in the content directory (use mp4:filename.mp4)
  • A stream elsewhere (requires some additional modules)
  • start : The number of seconds into the video to start playing. If this is a live source, use the value -2.
  • length : The number of seconds to play the video. The value -1 indicates to play until it ends.

Using start/length is a useful way to introduce commercial breaks or intermissions into a stream. This example would show BigBuckBunny.mp4 from the start, for 60 seconds, then cut to a commercial for the duration of the advertisement-1.mp4 file. After the commercial, it would resume and play for 2 more minutes, play a 30-second commercial from advertisement-2.mp4 and then plays the rest of theBigBuckBunny.mp4 file. If the playlist set to repeat, this will loop.

<video src="mp4:BigBuckBunny.m4v" start="0" length="60"/>
<video src="mp4:advertisement-1.mp4 start="0" length="-1"/>
<video src="mp4:BigBuckBunny.m4v" start="60" length="120"/>
<video src="mp4:advertisement-2.mp4 start="0" length="30"/>
<video src="mp4:BigBuckBunny.m4v" start="180" length="-1"/>

When a particular playlist has ended, and there are no others currently scheduled, it will default to the last playlist, even if that playlist’s repeat is set to false.

Here’s an example for our weekly service replays, and live sunday events:

<smil>
 <head>
 </head>
 <body>

  <stream name="playlist-high"></stream>
  <stream name="playlist-low"></stream>

  <playlist name="mon-l" playOnStream="playlist-low" repeat="false" scheduled="2011-01-17 07:45:00">
   <video src="mp4:traditions-l.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="mon-h" playOnStream="playlist-high" repeat="false" scheduled="2011-01-17 07:45:00">
   <video src="mp4:traditions-h.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="mon-loop-h" playOnStream="playlist-high" repeat="true" scheduled="2011-01-17 09:30:00">
   <video src="mp4:1-16-Loop-H.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="mon-loop-l" playOnStream="playlist-low" repeat="true" scheduled="2011-01-17 09:30:00">
   <video src="mp4:1-16-Loop-L.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="tue-l" playOnStream="playlist-low" repeat="false" scheduled="2011-01-18 12:45:00">
   <video src="mp4:praise-l.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="tue-h" playOnStream="playlist-high" repeat="false" scheduled="2011-01-18 12:45:00">
   <video src="mp4:praise-h.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="tue-loop-h" playOnStream="playlist-high" repeat="true" scheduled="2011-01-18 14:30:00">
   <video src="mp4:1-16-Loop-H.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="tue-loop-l" playOnStream="playlist-low" repeat="true" scheduled="2011-01-18 14:30:00">
   <video src="mp4:1-16-Loop-L.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="wed-l" playOnStream="playlist-low" repeat="false" scheduled="2011-01-19 21:45:00">
   <video src="mp4:praise-l.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="wed-h" playOnStream="playlist-high" repeat="false" scheduled="2011-01-19 21:45:00">
   <video src="mp4:praise-h.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="wed-loop-h" playOnStream="playlist-high" repeat="true" scheduled="2011-01-19 23:30:00">
   <video src="mp4:1-16-Loop-H.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="wed-loop-l" playOnStream="playlist-low" repeat="true" scheduled="2011-01-19 23:30:00">
   <video src="mp4:1-16-Loop-L.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="thu-l" playOnStream="playlist-low" repeat="false" scheduled="2011-01-20 03:15:00">
   <video src="mp4:traditions-l.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="thu-h" playOnStream="playlist-high" repeat="false" scheduled="2011-01-20 03:15:00">
   <video src="mp4:traditions-h.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="thu-loop-h" playOnStream="playlist-high" repeat="true" scheduled="2011-01-20 05:00:00">
   <video src="mp4:1-16-Loop-H.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="thu-loop-l" playOnStream="playlist-low" repeat="true" scheduled="2011-01-20 05:00:00">
   <video src="mp4:1-16-Loop-L.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="fri-l" playOnStream="playlist-low" repeat="false" scheduled="2011-01-21 07:45:00">
   <video src="mp4:traditions-l.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="fri-h" playOnStream="playlist-high" repeat="false" scheduled="2011-01-21 07:45:00">
   <video src="mp4:traditions-h.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="fri-loop-h" playOnStream="playlist-high" repeat="true" scheduled="2011-01-21 09:30:00">
   <video src="mp4:1-16-Loop-H.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="fri-loop-l" playOnStream="playlist-low" repeat="true" scheduled="2011-01-21 09:30:00">
   <video src="mp4:1-16-Loop-L.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="sat-l" playOnStream="playlist-low" repeat="false" scheduled="2011-01-22 02:45:00">
   <video src="mp4:praise-l.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="sat-h" playOnStream="playlist-high" repeat="false" scheduled="2011-01-22 02:45:00">
   <video src="mp4:praise-h.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="sat-loop-h" playOnStream="playlist-high" repeat="true" scheduled="2011-01-22 04:30:00">
   <video src="mp4:1-16-Loop-H.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="sat-loop-l" playOnStream="playlist-low" repeat="true" scheduled="2011-01-22 04:30:00">
   <video src="mp4:1-16-Loop-L.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="sun-am-high" playOnStream="playlist-high" repeat="false" scheduled="2011-01-23 11:30:00">
   <video src="/streaming-media-hosting-free-webhosting/mobile-2" start="-2" length="6300"/>
  </playlist>

  <playlist name="sun-am-low" playOnStream="playlist-low" repeat="false" scheduled="2011-01-23 11:30:00">
   <video src="/streaming-media-hosting-free-webhosting/mobile-1" start="-2" length="6300"/>
  </playlist>

  <playlist name="sun-am-loop-h" playOnStream="playlist-high" repeat="true" scheduled="2011-01-23 13:15:00">
   <video src="mp4:1-16-Loop-H.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="sun-am-loop-l" playOnStream="playlist-low" repeat="true" scheduled="2011-01-23 13:15:00">
   <video src="mp4:1-16-Loop-L.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="sun-pm-high" playOnStream="playlist-high" repeat="false" scheduled="2011-01-23 17:45:00">
   <video src="/streaming-media-hosting-free-webhosting/mobile-2" start="-2" length="6300"/>
  </playlist>

  <playlist name="sun-pm-low" playOnStream="playlist-low" repeat="false" scheduled="2011-01-23 17:45:00">
   <video src="/streaming-media-hosting-free-webhosting/mobile-1" start="-2" length="6300"/>
  </playlist>

  <playlist name="sun-pm-loop-h" playOnStream="playlist-high" repeat="true" scheduled="2011-01-23 19:30:00">
   <video src="mp4:1-16-Loop-H.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="sun-pm-loop-l" playOnStream="playlist-low" repeat="true" scheduled="2011-01-23 19:30:00">
   <video src="mp4:1-16-Loop-L.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="default-high" playOnStream="playlist-high" repeat="true" scheduled="2011-01-01 00:00:01">
   <video src="mp4:1-16-Loop-H.mp4" start="0" length="-1"/>
  </playlist>

  <playlist name="default-low" playOnStream="playlist-low" repeat="true" scheduled="2011-01-01 00:00:01">
   <video src="mp4:1-16-Loop-L.mp4" start="0" length="-1"/>
  </playlist>

 </body>
</smil>

Once your playlist is built, you’ll need to restart the service for it to read the new playlist in and schedule it internally.