How to Use FFmpeg -h for Demuxer Help

This guide explains how to use the -h (help) parameter in FFmpeg to view detailed documentation and available options for a specific demuxer. By targeting a single demuxer, you can quickly find its unique configuration parameters, supported formats, and default settings directly from your command line.

The Command Syntax

To view help for a specific demuxer, use the -h parameter followed by demuxer= and the name of the demuxer you want to query.

ffmpeg -h demuxer=demuxer_name

Step-by-Step Example

If you want to view the help options for the concat demuxer (used for joining media files), run the following command:

ffmpeg -h demuxer=concat

Understanding the Output

When you run the command, FFmpeg will print the specific options available for that demuxer. The output typically includes:

• Demuxer name and long name: Confirms the demuxer you are viewing.
• Options: A list of flags and settings you can apply.
• Type: The data type expected for each option (e.g., boolean, integer, string).
• Default values: The standard setting used if you do not specify the option.
• Description: A brief explanation of what each option does.

For example, querying the concat demuxer will reveal options like -safe (to allow or disallow unsafe file paths) and -auto_convert (to automatically convert packet data).

How to Find Available Demuxer Names

If you do not know the exact name of the demuxer you need help with, you can list all demuxers supported by your FFmpeg installation using the following command:

ffmpeg -demuxers

Once you locate the demuxer name from the list, plug it into the ffmpeg -h demuxer=name command to view its specific help documentation.