How to enable AVERAGE-BANDWIDTH attribute in Apple HLS master playlists (cupertinoEnableAverageBandwidth)

Newer versions of the Apple HLS specification include support for two bitrate attributes to be specified in Apple HLS master playlists, the BITRATE (peak bitrate) and AVERAGE-BITRATE (average bitrate). By default, Wowza Streaming Engine media server adds only the BITRATE attribute to Apple HLS master playlists. This article describes how to configure the cupertinoEnableAverageBandwidth property in Wowza Streaming Engine to enable the AVERAGE-BITRATE attribute in the master playlist.

Note: Wowza Streaming Engine™ 4.6.0 or later is required.
  1. In Wowza Streaming Engine Manager, click the Applications tab and select your application in the contents panel.
  2. In the details page, click the Properties tab, and then click Custom in the Quick Links bar.
  3. In the Custom section, click Add Custom Property, specify the following settings in the Add Custom Property dialog box, and then click Add:
    • Path - Select /Root/Application/HTTPStreamer
    • Name - Enter cupertinoEnableAverageBandwidth.
    • Type - Select Boolean.
    • Value - Enter true.
  4. Click Save, and then restart the application when prompted to apply the changes.

For adaptive bitrate streams, you must specify the average bitrate in your SMIL file in the <param> for each bitrate rendition:

<param name="cupertinoTag.AVERAGE-BANDWIDTH" value="[value-in-bits-per-second]" valuetype="data"/>

The average segment bitrate for each live stream rendition MUST be less than 110 percent of the AVERAGE-BANDWIDTH attribute.

The average segment bitrate for each VOD stream rendition MUST be within 10 percent of the AVERAGE-BANDWIDTH attribute.


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