Official documentation
FFmpeg Filters Documentation
FFmpeg project, 2026
Read the originalRead on October 17, 2026
- What it is
- The reference manual for the filters in the FFmpeg command-line tool, including the loudnorm filter that adjusts the loudness of an audio file to a target level.
- How much weight it carries
- The project's own manual for its released software. It states what each filter does and its options; it does not say how well any filter improves speech recognition on a given recording.
Facts taken from this source
- The loudnorm filter in ffmpeg performs EBU R128 loudness normalization, with both dynamic and linear normalization modes.
“EBU R128 loudness normalization. Includes both dynamic and linear normalization modes.” (loudnorm filter section)
- FFmpeg's subtitles filter draws subtitles onto the frames of a video.
“Draw subtitles on top of input video using the libass library” (11.248 subtitles)