Configure Tilt Factor in FFmpeg tiltsdr Filter

This article provides a straightforward guide on how to configure the tilt factor in the FFmpeg tiltsdr filter. You will learn the correct command-line syntax, the primary parameters used to adjust the tilt slope, and practical examples to help you apply these settings directly to your video processing workflows.

The tiltsdr filter in FFmpeg is designed to adjust the spectral tilt or color slope of Standard Dynamic Range (SDR) video signals. Configuring the tilt factor allows you to correct luminance or chrominance distribution imbalances across the frame, shifting the intensity towards the highlights or shadows.

The Tilt Parameter Syntax

The primary option used to control the tilt factor in the tiltsdr filter is tilt (which can also be abbreviated as t).

The basic filter syntax is defined as follows:

-vf "tiltsdr=tilt=<value>"

Parameter Values and Behavior

The tilt factor accepts a floating-point number, typically ranging from -1.0 to 1.0:

0.0 (Default): No tilt is applied. The signal levels remain neutral and unchanged.
Positive Values (0.1 to 1.0): Shifts the slope positively, increasing the intensity of the upper-range signals (brightening highlights).
Negative Values (-0.1 to -1.0): Shifts the slope negatively, emphasizing the lower-range signals (deepening shadows).

Practical Command Examples

Below are practical FFmpeg commands demonstrating how to apply and adjust the tilt factor.

1. Applying a Positive Tilt

To apply a moderate positive tilt of 0.3 to enhance the brighter regions of your SDR video, use the following command:

ffmpeg -i input.mp4 -vf "tiltsdr=tilt=0.3" output.mp4

2. Applying a Negative Tilt

To apply a negative tilt of -0.5 to darken the image slope and favor the shadow ranges, run:

ffmpeg -i input.mp4 -vf "tiltsdr=tilt=-0.5" output.mp4

3. Combining Tilt with Additional Parameters

If you need to configure the tilt factor alongside other filter options such as the processing channel or slope limiters, separate the key-value pairs with a colon (:):

ffmpeg -i input.mp4 -vf "tiltsdr=tilt=0.2:slope=1.5" output.mp4