Tone Curve Color Correction with the FFmpeg curves Filter

Left is the original. Right is the same frame with curves=preset=vintage, a single preset.

Source: Tears of Steel (CC) Blender Foundation | mango.blender.org, CC BY 3.0. One frame of the film, processed with the filter shown.

Basic Commands

Boost Contrast with the Master Curve (S-Curve)

ffmpeg -i input.mp4 -vf "curves=master='0/0 0.25/0.15 0.5/0.5 0.75/0.85 1/1'" -pix_fmt yuv420p output.mp4

master is one curve applied to the red, green and blue channels together. Each pair such as 0/0 is a control point written as input value/output value: a point the curve passes through. This example lowers the dark tones and raises the bright ones. That S-shaped curve increases contrast. For a quick brightness or contrast change, the eq filter is simpler. curves works in RGB, so without -pix_fmt yuv420p the H.264 output is 4:4:4, which many players and devices cannot play.

Adjust the Red Channel Only

ffmpeg -i input.mp4 -vf "curves=red='0/0 0.5/0.6 1/1'" -pix_fmt yuv420p output.mp4

red, green and blue set a separate curve for each channel. This example raises only the red midtones.

Use a Built-in Preset

ffmpeg -i input.mp4 -vf "curves=preset=vintage" -pix_fmt yuv420p output.mp4

preset accepts the names in the table below.

List of Built-in Presets

ffmpeg -i input.mp4 -vf "curves=preset=cross_process" -pix_fmt yuv420p output.mp4

How to Write Control Points

Write each control point as input value/output value and separate the points with spaces. Values run from 0.0 (darkest) to 1.0 (brightest).

master='0/0 0.5/0.7 1/1'

• 0/0 — black (input 0 → output 0)
• 0.5/0.7 — raises the midtones
• 1/1 — white (input 1 → output 1)

FFmpeg joins the points with a smooth curve (spline interpolation). More points give you finer control.

Combining Individual RGB Curves

ffmpeg -i input.mp4 \
  -vf "curves=red='0/0 1/0.9':green='0/0 1/0.95':blue='0/0 0.8/1 1/1'" -pix_fmt yuv420p \
  output.mp4

This lowers the red and green highlights slightly and lifts the blue, which gives the whole image a cooler, bluer look. To shift the hue itself, combine it with the hue filter.

Combining a Preset with the Master Curve

ffmpeg -i input.mp4 \
  -vf "curves=preset=vintage:master='0/0 0.5/0.55 1/1'" -pix_fmt yuv420p \
  output.mp4

vintage sets the overall look, and master adjusts the brightness on top of it.

Applying to Still Images

ffmpeg -i input.jpg -vf "curves=preset=increase_contrast" output.jpg

Bad Example

Bad example: control points are not in ascending order
ffmpeg -i input.mp4 -vf "curves=master='0/0 0.8/0.3 0.5/0.7 1/1'" output.mp4

List the points so that the input values (the left-hand numbers) go from small to large. When they are out of order, as here, FFmpeg stops with an error that ends in not strictly increasing on the x-axis.

Caveats

• curves works in RGB. YUV video is converted to RGB automatically.
• You can give a single control point. Below the first point and above the last one, the curve stays flat at that point’s output value, so with one point the whole image becomes a single value. To shape the full range, include the end points 0/… and 1/….
• If you add red, green, blue or master to a preset, your curve replaces the preset’s curve for that channel. Presets made only of a master curve, such as increase_contrast and lighter, have no effect once you add master.

Measured: time and size

This is the command that was measured:

ffmpeg -i input.mp4 -vf curves=preset=increase_contrast -c:v libx264 -crf 23 -preset medium -an output.mp4

Rig: Core i9-14900KF (32 threads), FFmpeg 8.1 (gyan.dev). Source: 1920x1080, 30 fps, 120 s, 351.4 MB (Big Buck Bunny, looped, CC BY 3.0). Measured 2026-09-05, one command at a time. The raw numbers are in the dataset.

Reading the numbers

Re-encoding the same clip with the same x264 settings and no filter takes 27.97 s. The measured command has no -pix_fmt, so it wrote 4:4:4 (yuv444p), while the no-filter re-encode wrote 4:2:0 (yuv420p). 4:4:4 keeps colour at full resolution, so x264 has twice as many values to encode in each frame as with 4:2:0. That larger encode is a large part of the extra 14 seconds. The rest is the conversion to RGB and back, and the curve itself.

The 120-second source finished in 42.01 s, 2.86x faster than real time.

The file grew by 13.4% because of what increase_contrast does. CRF 23 keeps the quality constant and lets the file size change. A steeper tone curve increases the contrast of edges and noise, so x264 needs more bits to keep the same quality.

Other operations timed on the same two-minute clip: a 720p downscale took 18.43 s and the no-filter re-encode 27.97 s, both faster than curves. colorbalance + eq took 53.29 s and boxblur 59.37 s, both slower. A VP9 transcode of the same clip took 729.16 s.

The bigger difference is whether the video is re-encoded at all. Operations that copy the video with -c copy or -c:v copy (no re-encoding) finished in about a second: stream mapping took 0.41 s, moving the moov atom 0.49 s, and an audio fade that re-encodes only the audio 1.03 s. Colour changes can never be that fast, because every frame has to be decoded, filtered and encoded again. When you only want to judge how a curve looks, first cut a few seconds out with -ss/-t and a stream copy, then run curves on that short clip. You can then try many more curves in the same time.

The figure is for preset=increase_contrast only; a hand-written master curve was not timed. -an drops the audio, so the 42.01 s includes no audio processing.

Start with a gentle curve, for example points at 0.25/0.2 and 0.75/0.8. Then check for crushed blacks, clipped highlights and banding in smooth skies or walls. Exporting the same frame as a PNG before and after makes the comparison easier.

Related Filters

• hue — adjusts hue, saturation, and brightness
• eq — adjusts brightness, contrast, and gamma
• colorbalance — color correction for shadows, midtones, and highlights
• lut3d — color grading via a 3D LUT