Configure FFmpeg Tremolo Filter Frequency and Depth

This guide explains how to configure the modulation frequency and depth parameters using the tremolo audio filter in FFmpeg. You will learn the syntax, parameter values, and practical command-line examples required to apply a tremolo effect to your audio files.

The FFmpeg tremolo filter modulates the amplitude of an audio signal with a low-frequency sinusoidal oscillator. To control this effect, the filter utilizes two primary parameters: frequency and depth.

The Tremolo Parameters

• Frequency (f): This parameter defines the modulation frequency in Hz (cycles per second), which determines how fast the volume fluctuates.
  • Range: 0.1 to 20000.0 Hz
  • Default: 5.0 Hz
• Depth (d): This parameter defines the modulation depth, which determines the intensity of the volume fluctuation (how quiet the audio gets during the modulation dips).
  • Range: 0.0 to 1.0 (where 0.0 is no effect and 1.0 is maximum volume modulation)
  • Default: 0.5

Syntax and Configuration

The basic syntax for applying the tremolo filter is:

-af "tremolo=f=VALUE:d=VALUE"

Alternatively, you can use the short-hand positional syntax:

-af "tremolo=FREQUENCY:DEPTH"

Practical Examples

1. Standard Tremolo (5 Hz Frequency, 0.5 Depth) This uses the default settings, creating a moderate, noticeable pulsing effect:

ffmpeg -i input.wav -af "tremolo=f=5.0:d=0.5" output.wav

2. Fast and Intense Tremolo (12 Hz Frequency, 0.9 Depth) This configuration creates a rapid, dramatic stuttering effect by increasing the speed and making the volume drops much more severe:

ffmpeg -i input.wav -af "tremolo=f=12.0:d=0.9" output.wav

3. Slow and Subtle Tremolo (2 Hz Frequency, 0.3 Depth) This configuration creates a gentle, slow swelling effect suitable for ambient sounds:

ffmpeg -i input.wav -af "tremolo=f=2.0:d=0.3" output.wav