How to View FFmpeg Filter Help with -h Parameter

This article explains how to use the -h parameter in FFmpeg to access detailed documentation and usage instructions for specific audio and video filters. You will learn the exact command syntax and how to interpret the output to streamline your media processing workflows.

To view help for a specific FFmpeg filter, you must use the -h (help) parameter followed by the filter= specifier and the name of the filter you want to investigate. The basic syntax for this command is:

ffmpeg -h filter=filter_name

Video Filter Example

If you want to see the available options, parameter types, and default values for the video resizing filter named scale, run the following command in your terminal:

ffmpeg -h filter=scale

The output will display the filter’s description, its input and output slice capabilities, and a detailed list of supported options (such as width, height, and eval) along with their expected data types and default settings.

Audio Filter Example

Similarly, to view the help documentation for an audio filter like volume, use:

ffmpeg -h filter=volume

This command outputs the specific parameters for adjusting audio levels, showing you how to set the volume using mathematical expressions, decibels, or decimal values.

Using this built-in help command allows you to quickly verify filter syntax and options directly from the command line without needing to search through external online documentation.