By default, live Microsoft Smooth Streaming (smoothstreaming) audio and video fragment durations aren't aligned, whereas video-on-demand fragments are aligned. Data packets received by Wowza Streaming Engine™ media server software are sent to the smoothstreamingpacketizer where the H.264 video and AAC/MP3 audio stream are broken into chunks.
To turn on alignment for live Smooth Streaming, add the following properties to the LiveStreamPacketizer/Properties container in [install-dir]/conf/[application]/Application.xml:
<Properties> <Property> <Name>smoothPacketSortTime</Name> <Value>500</Value> <Type>Integer</Type> </Property> <Property> <Name>smoothAlignAudioWithVideo</Name> <Value>true</Value> <Type>Boolean</Type> </Property> </Properties>
You should use these two properties together because the alignment will be better if the packets are sorted. This mechanism is based on keyframe interval, so adding these properties won't increase latency.
This also requires that smoothstreamingpacketizer be set in Streams/LiveStreamPacketizers in [install-dir]/conf/[application]/Application.xml:
<LiveStreamPacketizers>cupertinostreamingpacketizer, smoothstreamingpacketizer,cupertinostreamingrepeater, smoothstreamingrepeater</LiveStreamPacketizers>