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 available video encoding parameters and their current values. You can use this information to adjust the transcoding parameters for transcoded output renditions.

Contents

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. You can find Transcoder templates at this location ([install-dir]/transcoder/templates) in your Wowza Streaming Engine installation. 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 may look like this:

# long: entropy_coding_mode: coding mode: 0=H264_CAVLC or 1=H264_CABAC

You can then use this information to adjust the transcoded video output with the available video encoding parameters that are logged.

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

Example configuration

Let's take this entropy coding mode video parameter defined as available and in use in the wowzastreamingengine_access.log file:

# long: entropy_coding_mode: coding mode: 0=H264_CAVLC or 1=H264_CABAC

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

<Parameter>
    <!-- Symbol mode: 0=CAVLC, 1(default)=CABA -->
    <Name>mainconcept.entropy_coding_mode</Name>
    <Value>0</Value>
    <Type>Long</Type>
</Parameter>

Note: Logs do not report a warning or error for invalid parameter values. If you specify an invalid value, the Transcoder uses the default value for the parameter instead, which is reflected in the logs.

More resources

• Use video decoding parameters with the Transcoder in Wowza Streaming Engine
• Use audio encoding parameters with the Transcoder in Wowza Streaming Engine
• Set up and run Transcoder in Wowza Streaming Engine