• How to turn on an RTP jitter buffer and packet loss logging (RTP and MPEG-TS)

    A jitter buffer is an area where packets are collected and stored before being sent to the depacketizer at regularly spaced intervals to enable more even playback. This article explains how to configure an RTP jitter buffer in Wowza™ media server software. It also explains how to log packet loss in your live RTP and MPEG-TS/UDP streams.

    You can configure application properties in Wowza Streaming Engine™ Manager or by editing [install-dir]/conf/[application]/Application.xml. If you make changes to Application.xml and you're using Wowza Streaming Engine media server software, any supported settings are displayed in the manager the next time it's started. Wowza Media Server™ software doesn't support Wowza Streaming Engine Manager, so you must edit Application.xml in a text editor if you're running Media Server software.

    Contents


    Configure an RTP jitter buffer
    Configure packet loss logging

    Configure an RTP jitter buffer


    A jitter buffer is an area where packets can be collected and stored before being sent to the depacketizer at regularly spaced intervals to enable more even playback.

    Wowza Streaming Engine Manager configuration

    To configure an RTP jitter buffer in Wowza Streaming Engine Manager:

    1. In the manager Welcome page, 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 RTP Jitter Buffer 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 RTP Jitter Buffer properties area and make the following changes:

      • Select the Enabled check box next to rtpDePacketizerWrapper and enter the value com.wowza.wms.rtp.depacketizer.RTPDePacketizerWrapperPacketSorter.

      • Select the Enabled check box next to rtpDePacketizerPacketSorterBufferTime and change the size (in milliseconds) of the jitter buffer from the default value if desired. This time adds to the overall latency of the live stream.

      • Select the Enabled check box next to rtpDePacketizerPacketSorterFlushTime and change the time (in milliseconds) from the default value if desired. This is the time when the buffer will be flushed.

    5. Click Save, and then restart the application when prompted to apply the changes.

    XML configuration

    To configure an RTP jitter buffer in Application.xml:

    1. Use a text editor to open the [install-dir]/conf/[application]/Application.xml file for your live application and add the following properties to the RTP/Properties container. Be sure to add the properties to the correct <Properties> container in Application.xml as there are several such containers in the file.
      <Property>
      	<Name>rtpDePacketizerWrapper</Name>
      	<Value>com.wowza.wms.rtp.depacketizer.RTPDePacketizerWrapperPacketSorter</Value>
      </Property>
      <Property>
      	<Name>rtpDePacketizerPacketSorterBufferTime</Name>
      	<Value>500</Value>
      	<Type>Integer</Type>
      </Property>
      <Property>
      	<Name>rtpDePacketizerPacketSorterFlushTime</Name>
      	<Value>10</Value>
      	<Type>Integer</Type>
      </Property>
    2. Restart the Wowza media server software to apply the changes.

    Configure packet loss logging


    Use the following procedures to log information about lost packets in live RTP and MPEG-TS streams to the access log file in [install-dir]/logs.

    Wowza Streaming Engine Manager configuration

    To configure packet loss logging in Wowza Streaming Engine Manager:

    1. In the manager Welcome page, 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 RTP Jitter Buffer 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 RTP Jitter Buffer properties area and make the following changes depending on stream type:

      • To enable logging of lost packets in RTP live streams, select the Enabled check box next to rtpDePacketizerPacketSorterLogPacketLoss and set the value to True.

      • If the stream is MPEG-TS over UDP (no RTP involved), select the Enabled check box next to logIncompleteMPEGTSVideoFrames and set the value to True.

    5. Click Save, and then restart the application when prompted to apply the changes.

    XML configuration

    To configure packet loss logging in Application.xml:

    1. Use a text editor to open the [install-dir]/conf/[application]/Application.xml file for your live application and add the following properties to the RTP/Properties container. Be sure to add the properties to the correct <Properties> container in Application.xml as there are several such containers in the file.
      <Property>
      	<Name>rtpDePacketizerPacketSorterLogPacketLoss</Name>
      	<Value>true</Value>
      	<Type>Boolean</Type>
      </Property>
      <Property>
      	<Name>logIncompleteMPEGTSVideoFrames</Name>
      	<Value>true</Value>
      	<Type>Boolean</Type>
      </Property>
    2. Restart the Wowza media server software to apply the changes.


    Updated: For Wowza Streaming Engine on 12-04-2014.

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