Boost High Frequencies with FFmpeg Treble Filter

This article provides a straightforward guide on how to use the treble filter in FFmpeg to boost high-frequency audio. You will learn the basic command syntax, key parameters like gain and frequency, and practical examples to enhance the clarity and brightness of your audio files.

The treble filter in FFmpeg is a shelving filter, meaning it boosts or attenuates frequencies above a specified cutoff point.

Basic Syntax

To apply the treble filter, use the audio filter flag (-af) followed by the filter name and its parameters:

ffmpeg -i input.mp3 -af "treble=g=GAIN" output.mp3

Key Parameters

The treble filter accepts several parameters to customize how the high frequencies are altered:

• g (gain): The amount of boost or attenuation in dB. To boost the treble, use a positive value (e.g., g=6 for a 6 dB boost). To reduce treble, use a negative value (e.g., g=-6). The default is 0.
• f (frequency): The center frequency in Hz where the filter begins to apply. The default frequency is 3000 Hz.
• w (width): The bandwidth of the filter, which determines how steep the transition is. It can be specified in octaves, Q-factor, or Hz. The default is 0.5.

Practical Examples

1. Basic Treble Boost

To apply a standard 6 dB boost to frequencies above the default 3000 Hz, use the following command:

ffmpeg -i input.wav -af "treble=g=6" output.wav

2. Boosting Specific High Frequencies

If you want to target higher frequencies, such as 8000 Hz (8 kHz), and boost them by 8 dB, define both the gain (g) and frequency (f) parameters:

ffmpeg -i input.wav -af "treble=g=8:f=8000" output.wav

3. Adjusting Filter Width

To make the transition into the treble boost gentler or sharper, you can adjust the width (w) parameter. A wider shelf (higher value) creates a smoother transition:

ffmpeg -i input.wav -af "treble=g=5:f=5000:w=0.7" output.wav