How to control transcoded video with video encoding parameters

This article describes how to adjust the video in the transcoded output from Wowza Transcoder through the use of 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
More resources

Logging available video encoding parameters


When using Wowza 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 file in a text editor and add the following property to the <Properties> container in each <Encode> block in the transcoder 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 template files ([install-dir]/transcoder/templates) in your Wowza Streaming Engine™ installation. They can't be configured using Wowza Streaming Engine Manager.

Open the transcoder template file 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 the Wowza media server for the changes to take effect.
 
Note: Older versions of the example transcoder templates may not have a <Parameters> container for the <Video> encoding section. Add this container if it's missing from your transcoder 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 file:
<Parameter>
	<!-- 0: H264_CAVLC or 1: H264_CABAC -->
	<Name>mainconcept.entropy_coding_mode</Name>
	<Value>0</Value>
	<Type>Long</Type>
</Parameter>

More resources


How to set up and run Wowza Transcoder

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