FFAStrans forum

Hi

What is the best command to use if I want to input a .MXF file and want it to check if it EBU R128 and make sure its -23 LUFS?

Thanks.

Is this a FFAStrans or ffmpeg question? FFAStrans has inbuilt loudness detection node but it does not do automatic correction without also reencoding the video.

-steinar

@JohnB1... just add the analyze node and set loudness to -23 by flagging "conform volume to" in your processing node.
This will result in a loudness that should be -23dB and in the specs of EBU R128 for broadcast and I recommend you to do it this way.
There's actual a way to do that yourself via Avisynth, but I DO NOT recommend it 'cause Avisynth normalizes audio by peak and it's very likely that it will screw things up or bring unexpected results. I'm talking about AmplifyDB and Normalize.

Avisynth (not the best way to do it):

Normalize performs peak normalization, so you have to set the amplitude of the loudest audio. For a particular peak decibel level, you gotta use the equation volume = 10^dB/20. For instance, to set a -3dB peak with volume = 10^-3/20 or 0.7079.
In this case you wanna set it to -23 LUFS it's gonna be about 0.10, but 0.11 should be fine as well.

In other words, if you wanna use Avisynth, put this in your custom avisynth script node:

ResampleAudio(48000)
Normalize(volume=0.10, show=false)