Normalization is a color correction filter that standardizes the RGB values in each frame of a video. With the use of histogram and contrast stretching, FFmpeg can quickly fix issues like rapid brightness changes and flickering. Below is an example of normalization at the highest strength:
$ ffmpeg -i input.mp4 -vf "normalize=strength=1" output.mp4
Tip: If this filter is applied to an MP4, you may need to add a pixel format, -pix_fmt yuv420p, for the previewer to work on macOS.
normalize
Indicates the normalization filter name
strength
Indicates the strength of the normalization, large the value higher the strength (1.0 to 0.0 with default 1.0)
smoothing
Indicates setting a temporal smoothing based on the previous frame (1 or 0 with a default 0 - no smoothing)
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