Use video encoding parameters with the Transcoder in Wowza Streaming Engine

This article describes how to adjust the video in transcoded output from Wowza Streaming Engine™ media server software through video encoding parameters. Users with advanced encoding knowledge can log all of the video encoding parameters that are available, and their current values, and use this information to adjust the transcoding parameters for transcoded output renditions.

Contents


Logging available video encoding parameters
Configuring video encoding parameters
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Logging available video encoding parameters


When using Transcoder, you can log all available video encoding parameters with their current values for a given <Encode> block to the wowzastreamingengine_access.log file. To do this, open the Transcoder template in a text editor and add the following property to the <Properties> container in each <Encode> block in the template.

<Property>
    <Name>logVideoEncodingParameters</Name>
    <Value>true</Value>
    <Type>Boolean</Type>
</Property>

A section of the data logged in the wowzastreamingengine_access.log file might look like this:

# long: coding mode: 0: H264_CAVLC or 1: H264_CABAC
mainconcept.entropy_coding_mode: 1

You can then use this information as a basis for adjusting the transcoded video output using the available video encoding parameters that are logged.
 
Note: The data logged will vary depending on the hardware in use and the codec applied to each transcoded output rendition.

Configuring video encoding parameters


You must use a text editor to configure video parameters in the Transcoder templates ([install-dir]/transcoder/templates) in your Wowza Streaming Engine installation. They can't be configured using Wowza Streaming Engine Manager.

Open the Transcoder template in a text editor and add a <Parameter> section to the <Video>/<Parameters> container in each <Encode> block that you want to modify, as shown in the example below. A single template can have multiple <Encode> blocks (one for each encoded bitrate in the output stream). Then restart Wowza Streaming Engine.

Note: Older versions of the example templates may not have a <Parameters> container for the <Video> encoding section. Add the container if it's missing from the template.

Example configuration

As an example, for this entropy method video parameter defined as available and in use in the wowzastreamingengine_access.log file:

# long: coding mode: 0: H264_CAVLC or 1: H264_CABAC
mainconcept.entropy_coding_mode: 1

You can use this information to change the entropy method being used by adding the following <Parameter> section to the <Video>/<Parameters> container in an <Encode> block in your template:

<Parameter>
    <!-- 0: H264_CAVLC or 1: H264_CABAC -->
    <Name>mainconcept.entropy_coding_mode</Name>
    <Value>0</Value>
    <Type>Long</Type>
</Parameter>

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