Configure Adobe HDS packetization in Wowza Streaming Engine

This article describes how to configure properties in Wowza Streaming Engine™ media server software to control how the Adobe HDS packetizer (sanjosestreaming) splits streams into segments for playback on Flash clients.

Note: Wowza Streaming Engine 4.0.0 or later is required.

Configure Adobe HDS packetization in Wowza Streaming Engine Manager


Configure for live streams

  1. In Wowza Streaming Engine Manager, click the Applications tab at the top of the page.
     
  2. In the Applications contents panel, click the name of your live application (such as live).
     
  3. On the live application page Properties tab, click San Jose Streaming Packetizer in the Quick Links bar.
     
    Note: Access to the Properties tab is limited to administrators with advanced permissions. For more information, see Manage credentials.

     
  4. Click Edit in the San Jose Streaming Packetizer properties area. To enable a property, select the Enabled check box for the property. You can also change the value for an enabled property from its default setting. All time values are in milliseconds and the values are set on a per-application basis. Refer to the San Jose segmenter property reference below for information about the individual properties you can use to manage the San Jose segmenter for live streams.


     
  5. Click Save, and then restart the application when prompted to apply the changes. 
Note: For more information about how to configure properties, see Configure properties.

San Jose segmenter property reference

  • sanjoseChunkDurationTarget - Sets the duration of each chunk in milliseconds.
     
  • sanjoseMaxChunkCount - Sets the maximum number of chunks stored in the available chunk list.
     
  • sanjosePlaylistChunkCount - Sets the number of items returned in the playlist.
     
  • sanjoseRepeaterChunkCount - Sets the number of chunks that are immediately sent from the origin to the edge after initial connection. This property is only required for Live Edge application types. A live edge application will have a StreamType of liverepeater-edge in the Application.xml file.

Property details

The audio and video packets from the live encoder enter Wowza Streaming Engine and are segmented into chunks based on time. The duration of each chunk is control by the sanjoseChunkDurationTarget setting (in millseconds). As the chunks are completed they are added to the available chunk list. The maximum number of chunks stored in the available chunk list is control by the sanjoseMaxChunkCount setting. When a stream is requested by Flash, a manifest.f4m is returned that contains the [n] most recently added chunks. The number of items returned in the manifest [n] is control by the sanjosePlaylistChunkCount setting.

The live stream repeater system delivers a single live stream in an origin/edge configuration to multiple edge servers. The first time a stream is requested from an edge server, it pulls the already segmented chunks from the origin to the edge for delivery to Flash clients. The sanjoseRepeaterChunkCount setting controls the number of chunks that are immediately sent from the origin to the edge upon initial connection. It's best if this setting is equal to or greater than sanjosePlaylistChunkCount but less then sanjoseMaxChunkCount. With Wowza Streaming Engine 4.5.0.02 and later, if you set the sanjoseRepeaterChunkCount to a value that is equal to or less than 0, the sanjosePlaylistChunkCount value is used.
 
Notes:
  • Chunks must start on a keyframe, so use a keyframe interval that is factor of the sanjoseChunkDurationTarget setting. For instance if sanjoseChunkDurationTarget is set to 10 seconds then use a keyframe interval of either 2, 2.5, 5, or 10 seconds.
     
  • To get a rough idea of the amount of memory used to store the chunks for a single live stream use the following formula:
     
    [total-memory-mb] = ([stream-bitrate-kbps]/([1024-kb-per-mb]*[8-bits-per-byte])) * [sanjoseChunkDurationTarget-seconds] * [sanjoseMaxChunkCount]

    For example a 500Kbps stream will consume the following amount of memory given the default settings above:
     
    (500/(1024*8)) * 10 * 10 = 6 MB of memory
  • You can add the sanjoseCalculateChunkIDBasedOnTimecode property to turn on chunk ID numbering based on incoming packet time. To do this, do the following:
     
    1. On the live application page Properties tab, click Custom in the Quick Links bar.
       
    2. In the Custom section, click Edit.
       
    3. Click Add Custom Property, specify the following settings in the Add Custom Property dialog box, and then click Add:
       
      • Path - Select /Root/LiveStreamPacketizers.
         
      • Name - Enter sanjoseCalculateChunkIDBasedOnTimecode.
         
      • Type - Select Boolean.
         
      • Value - To start Adobe HDS chunk IDs at 0, enter false. To calculate Adobe HDS chunk IDs based on the incoming live stream timecodes, enter true. (Use this mode to synchronize chunk IDs between two servers that packetize the same live stream.)
    4. Click Save, and then restart the application when prompted.

Configure for VOD streams

You can control the video-on-demand (VOD) chunk size by adding the sanjoseChunkDurationTarget property to your VOD application configuration.
 
  1. In Wowza Streaming Engine Manager, click the Applications tab at the top of the page.
     
  2. In the Applications contents panel, click the name of your VOD application (such as vod).
     
  3. On the VOD application page Properties tab, click Custom in the Quick Links bar.
     
    Note: Access to the Properties tab is limited to administrators with advanced permissions. For more information, see Manage credentials.
  4. In the Custom area, click Edit.
     
  5. Click Add Custom Property, specify the following custom property settings in the Add Custom Property dialog box, and then click Add.
     
    1. In Path, select /Root/Application/HTTPStreamer.
       
    2. In Name, enter sanjoseChunkDurationTarget.
       
    3. In Type, select Integer.
       
    4. In Value, enter a value (in milliseconds) to specify the default VOD chunk size.
  6. Click Save, and then restart the application when prompted.

Configure Adobe HDS packetization in XML


If you configured the properties in Wowza Streaming Engine Manager, you can skip this section. If you make changes to [install-dir]/conf/[application]/Application.xml, any supported settings are displayed in Wowza Streaming Engine Manager the next time it's started. You must edit Application.xml in a text editor if you're running Wowza Media Server.

All time values are in milliseconds.

Configure for live streams

  1. Use a text editor to open the Application.xml file for your live application. Then add the properties described in the San Jose segmenter property reference above to the <LiveStreamPacketizer>/<Properties> container. Be sure to add the properties to the correct <Properties> container in Application.xml as there are several in the file.
    <Property>
        <Name>sanjoseChunkDurationTarget</Name>
        <Value>10000</Value>
        <Type>Integer</Type>
    </Property>
    <Property>
        <Name>sanjoseMaxChunkCount</Name>
        <Value>10</Value>
        <Type>Integer</Type>
    </Property>
    <Property>
        <Name>sanjosePlaylistChunkCount</Name>
        <Value>4</Value>
        <Type>Integer</Type>
    </Property>
    <Property>
        <Name>sanjoseRepeaterChunkCount</Name>
        <Value>-1</Value>
        <Type>Integer</Type>
    </Property>
    <Property>
        <Name>sanjoseCalculateChunkIDBasedOnTimecode</Name>
        <Value>false</Value>
        <Type>Boolean</Type>
    </Property>
  2. Restart Wowza Streaming Engine.

Configure for VOD streams

  1. Open the Application.xml file for your VOD application using a text editor and then add the sanjoseChunkDurationTarget property to the <HTTPStreamer>/<Properties> container. Be sure to add the properties to the correct <Properties> container in Application.xml as there are several in the file.
    <Property>
        <Name>sanjoseChunkDurationTarget</Name>
        <Value>10000</Value>
        <Type>Integer</Type>
    </Property>
  2. Restart Wowza Streaming Engine.