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More => Old Versions => JRiver Media Center 26 for Windows => Topic started by: rxp on August 02, 2020, 06:01:59 am

Title: Help with Expression Column
Post by: rxp on August 02, 2020, 06:01:59 am

Hey,

Just found out jriver can use r128 to calculate loudness. Saved me a ton of time trying to use ffmpeg-normalize to do so.

I'd like to read the figures as LUFS. All that involves is taking the Volume Level minus 23 (the target volume). I've been playing with the expression but can't get it to work.

Could someone please help me?

Or is there another way to specify a loudness target? I'd like to have a couple - one for big action blockbusters and one for quieter films. Rather than just a flat 83db.

I'd also be cool if you could calculate the dbA - this will tell you the potential hearing damage impact. In my own manual calcs using Audacity with an A weighted Graphic EQ curve loaded - a very loud movie like Skyfall which 8.5 LU was only 83dbA. So safe to listen with 0 on your AVR. Despite the LUFS being 93db K weighted

Thanks

Title: Re: Help with Expression Column
Post by: lepa on August 02, 2020, 12:57:41 pm

You mean like this?

Code: [Select]

Math(Number(Replace([Volume Level (R128)],/,,.)) - 23) LUFS

Title: Re: Help with Expression Column
Post by: rxp on August 02, 2020, 02:52:33 pm

Hey, thanks for responding.

Kind of - but I need to flip the R128 Volume Level to be a plus number. I can do that via

Code: [Select]

FormatNumber(Math([Volume Level (R128),0]-2*[Volume Level (R128),0]), 1,,/ LU,)
But then how do 23 minus the output of the above?

Title: Re: Help with Expression Column
Post by: lepa on August 02, 2020, 03:20:49 pm

One way to do above:

Code: [Select]

Math(Replace(Mid([Volume Level (R128),0],1,-1),/,,.) - 23) LU
or with formatnumber (didn't check formatting parameters, just copied from your example)

Code: [Select]

FormatNumber(Math(Replace([Volume Level (R128),0],/,,.) * -1 - 23), 1,,/ LU,)
Used Replace() function so it will work also in countries where decimal point is comma

Title: Re: Help with Expression Column
Post by: rxp on August 02, 2020, 09:35:57 pm

Thanks lepa, that last one worked perfect!

I only discovered recently that european countries use commas instead of periods for decimals!