Use FFmpeg tiltsdr Filter to Apply Tilt Curves

The tiltsdr filter in FFmpeg is a specialized video filter used to apply tilt curves to Standard Dynamic Range (SDR) video signals, allowing you to adjust color, luminance, and contrast distribution. This article provides a direct, practical guide on how to configure and run the tiltsdr filter in your command-line workflows, detailing its primary parameters and offering step-by-step implementation examples.

To use the tiltsdr filter, you must pass it to FFmpeg’s video filter graph using the -vf flag. The filter adjusts the input video’s pixels according to a mathematical tilt curve, which can stretch or compress highlights, midtones, and shadows depending on the parameters you define.

Basic Syntax

The basic syntax for applying the filter is as follows:

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

Key Parameters

You can customize the behavior of the tilt curve using several key parameters:

• tilt: Defines the slope or intensity of the tilt curve. A positive value tilts the curve to boost highlights and compress shadows, while a negative value tilts it in the opposite direction to darken highlights and lift shadows. (Default is typically 0.0).
• black: Adjusts the black level offset, shifting the lower anchor point of the tilt curve.
• white: Adjusts the white level offset, shifting the upper anchor point of the tilt curve.

Practical Examples

1. Applying a Gentle Highlight Boost To apply a subtle positive tilt that enhances the brightness of highlights while keeping shadows relatively controlled, use a low positive tilt value:

ffmpeg -i input.mp4 -vf "tiltsdr=tilt=0.15" output.mp4

2. Correcting Contrast with Tilt and Black Level Adjustments If you need to apply a negative tilt to soften harsh highlights while simultaneously protecting your black levels from crushing, you can combine the tilt and black parameters:

ffmpeg -i input.mp4 -vf "tiltsdr=tilt=-0.1:black=0.05" output.mp4

3. Applying the Filter to Specific Color Channels If your build of FFmpeg supports channel-specific routing for tiltsdr, you can target individual color components to correct color casts:

ffmpeg -i input.mp4 -vf "tiltsdr=tilt=0.2:white=0.95" output.mp4