How to Get Help for a Specific FFmpeg Decoder

This article explains how to use the FFmpeg help (-h) parameter to view detailed information, capabilities, and configuration options for any specific decoder. By targeting a single decoder, you can quickly find its supported options and private flags without sifting through the entire FFmpeg manual.

To view help for a specific decoder in FFmpeg, use the -h parameter followed by the decoder= specifier and the exact name of the decoder.

The basic command syntax is:

ffmpeg -h decoder=decoder_name

For example, to view the help documentation and available options for the H.264 video decoder, run the following command:

ffmpeg -h decoder=h264

For an audio decoder like AAC, the command is:

ffmpeg -h decoder=aac

Understanding the Output

When you run this command, FFmpeg outputs a dedicated block of information containing:

• Decoder Metadata: The official name, long name, and the media type (video, audio, or subtitle).
• Capabilities: Information on whether the decoder supports features like frame-level multithreading, slice-level multithreading, or experimental features.
• Private Options: A list of specific parameters you can fine-tune for this decoder, including their command-line flags, descriptions, default values, and valid ranges.

If you do not know the exact name of the decoder you want to query, you can find a list of all decoders compiled into your FFmpeg installation by running:

ffmpeg -decoders

Once you locate the required decoder name from that list, plug it into the -h decoder=name command to view its specific documentation.