MaxCLLFind

Abstract
Author	Tom Arrow
Version	v0.35
Download	MaxCLLFindAVS.v0.35.zip
Category	Debug filter
License	?
Discussion	Doom9 Thread

Description

PQ HDR Analyzer plugin for AviSynth+, analyzes MaxCLL and MaxFALL and writes that to a text file after closing the application that is calling AviSynth+.

The created textfile's name is "MaxCLLFind_Results0.txt". It will be overwritten if it already exists.

Requirements

• [x64] AviSynth+
• Supported color formats: RGB64

Syntax and Parameters

MaxCLLFind (clip, int "maxFallAlgorithm")

clip   =

Input clip, must be 16-bit RGB (RGB64).

int  maxFallAlgorithm = 0

The default MaxFALL algorithm uses the SMPTE recommendation of averaging max(R,G,B) across all pixels, meaning the brightest channel of each pixel goes into the average.

If you want the average of all channels of all pixels (not the official recommendation) instead, do this:

maxFallAlgorithm=1

This is more for your own curiosity and might lead to playback problems like flickering if used as actual HDR metadata, since it typically leads to typically slightly lower average intensity readings and if the TV bases its own dimming on the official recommendation, it might dim the image when it reaches a higher FALL than your calculated MaxFALL, which will almost certainly happen.

Examples

clip.MaxCLLFind()

Load in VirtualDub and click Play. After video is finished playing, close VirtualDub. The plugin also writes the Average FALL (frame average light level) into the text file. If you want this result to be accurate, make sure to not load any frame more than once.

If your HDR clip isn't RGB64, convert it first. This plugin only accepts RGB64 input.

For example, let's say you are loading a HDR HEVC YUV file, do this:

clip = clip.ConvertToRGB64(matrix="Rec2020")
clip.MaxCLLFind()

External Links

• GitHub - Source code repository.

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