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
Configuring video encoding parameters
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
The video parameters in the transcoder templates cannot currently be configured in WSE Manager. They must be updated in the [install-dir]/transcoder/templates directory of your WSE server.
To edit a transcoder template, open the [install-dir]/transcoder/templates directory and select a transcoder template. A single template may contain one <Encode> block for each encoded bitrate in the output stream. For each <Encode> block, add a <Parameter> section to the <Video>/<Parameters> container. (See the example configuration below.) Then restart WSE.
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.
