Loudness correction to EBU r128

Questions and answers on how to get the most out of FFAStrans
admin
Site Admin
Posts: 1458
Joined: Sat Feb 08, 2014 10:39 pm

Re: Loudness correction to EBU r128

Post by admin » Tue Nov 19, 2019 1:34 pm

Are you sure eFF checks the audio as stereo-pair and not as two separate mono?

-steinar

abul
Posts: 54
Joined: Wed Sep 11, 2019 12:45 pm

Re: Loudness correction to EBU r128

Post by abul » Tue Nov 19, 2019 2:08 pm

I just noticed something.

I did, loudness analyse to 2 (stereo) and XDCAM to -20
eFF says the file is -23 which passed????

MXF did same but -23 for XDCAM
output came as -23 for first audio but for 2nd audio, it was -23.1

any suggestion/help with this??
admin wrote:
Tue Nov 19, 2019 1:34 pm
Are you sure eFF checks the audio as stereo-pair and not as two separate mono?

I doubled checked, it 2 stereo

admin
Site Admin
Posts: 1458
Joined: Sat Feb 08, 2014 10:39 pm

Re: Loudness correction to EBU r128

Post by admin » Tue Nov 19, 2019 5:41 pm

Ok, this does not make much sense but what DOES make sense is the difference in 3 dB, which is what you would expect if you correct loudness for stereo but analyze, or run QC on eFF as two mono. I don't know eFF but the output log (?) from it SHOULD contain ONE result and mention something about stereo, dual channel, 1+2 or something in that reign. If it says anything about mono... AND you have two results, then I think it's mis-configured for the purpose of analyzing two audio channels as stereo. So please export and post your current workflow along with complete output from eFF.

-steinar

emcodem
Posts: 656
Joined: Wed Sep 19, 2018 8:11 am

Re: Loudness correction to EBU r128

Post by emcodem » Wed Nov 20, 2019 9:15 am

@abul
Up in front, it is very important that you share your workflow xml and the resulting pdf or xml from your Eff analyzer just as admin says.

Furthermore, please check the results using these files:
https://drive.google.com/open?id=1JpVOu ... yo-3bH7jfw

What you find on the drive is a .wav file that you can use for loudness testing, it has a stereo pair with the maximum possible volume. You can throw it at your ffastrans workflow and check the corrected result.
Also you find an already corrected .mxf file which actually is just the output of my example loudness workflow and the wav file as input. This MXF MUST show -23db in your analyzer, if not, the analyzer does not measure in stereo pairs.

Just to be sure i threw the corrected mxf output to an Eff installation here, the result should look like this for you:
eff.png
eff.png (61.54 KiB) Viewed 2154 times

abul
Posts: 54
Joined: Wed Sep 11, 2019 12:45 pm

Re: Loudness correction to EBU r128

Post by abul » Wed Nov 20, 2019 10:01 am

Hi,

Thanks, guys, this is the output
Attachments
stereo_not.png
stereo_not.png (67.26 KiB) Viewed 2146 times
stereo.png
stereo.png (47.13 KiB) Viewed 2146 times
Loudness_Transcode.xml
(17.34 KiB) Downloaded 57 times

emcodem
Posts: 656
Joined: Wed Sep 19, 2018 8:11 am

Re: Loudness correction to EBU r128

Post by emcodem » Wed Nov 20, 2019 10:24 am

Hey,
so just as steinar said, you are checking for mono track configuration. In your Report, you see that the loudness check is done using mono configuration:
Channel Group Layout: Mono_Mono

So you need to decide if you set ffastrans loudness node to do mono channel analyzing OR you need to set your Eff to Stereo config.
What is the actual content of your files when you listen to it, is it stereo or mono?

abul
Posts: 54
Joined: Wed Sep 11, 2019 12:45 pm

Re: Loudness correction to EBU r128

Post by abul » Wed Nov 20, 2019 12:06 pm

This is my config for eFF
Attachments
eff4.png
eff4.png (2.1 KiB) Viewed 2135 times
eff2.png
eff2.png (14.52 KiB) Viewed 2135 times
eff1.png
eff1.png (17.01 KiB) Viewed 2135 times

emcodem
Posts: 656
Joined: Wed Sep 19, 2018 8:11 am

Re: Loudness correction to EBU r128

Post by emcodem » Wed Nov 20, 2019 12:20 pm

So what you want is to check a stereo configuration, is that correct?

In the end all you need to do is to play with Eff settings up to the point where it writes in the test result (as in my screenshot):
Channel Group Layout:Stereo

Sorry but i cannot help you with settings for this software, but it should be easy for you to get support from the vendor to help you set things correctly.

abul
Posts: 54
Joined: Wed Sep 11, 2019 12:45 pm

Re: Loudness correction to EBU r128

Post by abul » Mon Nov 25, 2019 5:14 pm

Thanks for the help guys,

I found my issue.

Right now, I am doing this.

Watch folder --> loudness --> XDCAM --> Custom ffmpeg node --> delivery

the custom FFmpeg node is mapping the video and audio channel.

Passing that through eff works.

The loudness is set to 2 stereo without loop analysis.

admin
Site Admin
Posts: 1458
Joined: Sat Feb 08, 2014 10:39 pm

Re: Loudness correction to EBU r128

Post by admin » Mon Nov 25, 2019 7:01 pm

Great that you got it working but I can't help thinking that the custom ffmpeg nodes should be totally unnecessary. Could you share your workflow? I'm curious on what good your custom node actually does.

-steinar

Post Reply