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DVD Dialnorm / EBU R128


TheBlimp

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I can't help but scratch my head on this one... I'm occassionally doing post for Indie/student shorts which go on DVD (no theatrical), and upon reading up a bit I hopefully understand correct now that the Dial track should be around -27db Leq (A), and if then I set Dialnorm to -27dB FS when encoding AC3, all should be (almost) good?

A few months ago I calibrated my monitors and now I'm doing post on another short, where I occasionally switch from 76dB (editing) to 83dB (mixing), which I figured should bring me in the ballpark without slavishly watching each meter movement... but please correct me if I'm wrong.

Now, when doing stuff for small TV stations, which still have the easy -9dBFS standard around here, all I do is to take my mix and normalize it to -9dB FS. I know, lazy, but they have been perfectly happy with it until now. Then comes EBU R128... I looked at my mixes with the free Orban EBU R128 meter, and they don't even look as bad as I thought they would. Maybe that's because I don't usually compress like a madman and keep around 10 dB of headroom. Am I correct in assuming that if I get my mixes to settle in at around -23 dB max on the EBU R128 meter, I'm in the recommended ballpark?

Sorry for the likely noobish questions, but the information I find everywhere is a bit too diverse and overly scientific to me, and I will definitely do further reading, but for now I just wanted to check if I have my basic concepts halfway right. What do you think? Fire away!

Cheers,

Mike

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Yes, some DVDs go beyond OdBFS (clipped)

As for the new reg.s (CALM act) and such, see:

"ATSC Recommended Practice:Techniques for Establishing and Maintaining Audio Loudness for Digital Television"

Sorry I don't have an exact URL.

Addendum: I find the ATSC levels quite adequate for DVD.

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Link: http://www.atsc.org/.../a_85-2011a.pdf

The Gearslutz Forum has had many discussions about dealing with the ITU (and now ATSC) Loudness Standard, particularly in regards to momentary vs. average vs. peak loudness levels. Some studio home video departments are very critical about these levels, particularly for average dialog levels and maximum peaks.

Both Waves and Nugen have decent, affordable plug-ins that will give you all the numbers required to check compatibility of mixes with the new standard:

http://www.nugenaudi...VST_AU_RTAS.php

http://www.waves.com...t.aspx?id=11884

One issue with the process is that some channels, companies, and game providers will arbitrarily reject anything that goes even one number beyond the spec -- without necessarily regarding the quality of the mix. A horrible-sounding mix could still pass these specs, provided the numbers were good. And conversely, a great mix might fail to hit the right numbers, but will still get rejected by QC.

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Both Waves and Nugen have decent, affordable plug-ins that will give you all the numbers required to check compatibility of mixes with the new standard:

http://www.nugenaudi...VST_AU_RTAS.php

http://www.waves.com...t.aspx?id=11884

Ozone 5 from Izotope now does this too.

http://izotope.com/products/audio/ozone/features/meterbridge.asp

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Marc, I've dug through the ATSC paper a bit... I found the following pieces really helpful:

"... representative sample of the anchor should be measured using a BS.1770 measurement [3]. If the Anchor Element cannot be identified and measured on its own, then the long term loudness of all elements of the soundtrack, over the entire duration, should be measured and reported as the Dialog Level"

"A representative section of the content that is dominated by typical dialog (i.e., not shouting or whispering) should be isolated and measured. In the absence of dialog, the loudness of the element of the content that a reasonable viewer would focus on when setting the volume control, should be measured. If neither technique is possible or practical, the loudness of the entire duration of the content should be measured."

"When generating content and the program delivery level requirement is unknown or has not been specified, mix Dialog Level to -24 LKFS with true peaks below -2 dB TP."

________________________________________

So to sum it up, insert an ITU BS1770 meter on the dialogue channel, normal speaking passage, and mix to -24 LKFS. Later on in the paper, section "comfort zone", it says that a drop of about -5dB and a rise of about 2.5 dB are "considered acceptable". Also helpful.

From what I hopefully have understood correctly: Normal speech passages at -24LKFS, true peaks -2dB max, louder passages around -21.5 dB LKFS and quiet ones at around -31dB, and I'm in the "comfort zone" ( ;D ). Then just set Dialnorm to -24. Should do for my purposes.

Thanks a ton, and everyone please feel free to correct me if I'm wrong and/or oversimplifying things.

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You may also want to check delivery documents on specific technical requirements. For example, NBC's broadcast and cable channels use this document:

https://na5.salesfor...ZRyClMCNKMULiE=

I think everybody is pretty much moving towards the ATSC recommended levels, but there are always exceptions. And I still hear dialogue levels, mix levels, and overall program levels bounce all over the place from week to week and channel to channel on cable or satellite. You still have to monitor and check levels on all audio channels, not just dialogue per se. I have had mixes kicked back on home video projects due totally to effects tracks (particularly explosions), even when it was far from clipping. They're often pretty insistent on nothing going over -10dBfs, no matter what.

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Thanks for the linky, Marc! It doesn't look half as confusing as I thought it would. I will definitely check dedicated station's broadcast delivery specs on time when needed - so far, it's only been local TV stations who still work with the "max -9dB FS" spec. At the moment, I'm trying to become better prepared in general - the 5.1 mix i just finished was just a student short, done in my what pros would consider a hilariously low end home studio and soundtrack pro (haha) with a lot of mouse clicking automation - my general setup is pretty lo fi, but I'm constantly trying to achieve the best I can with what I already have (though constantly upgrading here and there), and to me the concept of "getting better" also implies some general understanding of what problems I'll be facing in the future ...

Again, thanks a lot for the input and have a good one! -Mike

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In January 2011 I attended a joint meeting of the New York chapters of the AES, SMPTE, SBE, and IEEE BTS New York Chapter, at NBC Universal’s 30 Rock facility with regard to the at the time just signed into law CALM(Commercial Advertisement Loudness Mitigation) Act, which was passed by a unanimous Congressional vote. In February 2012 I attended another joint meeting, also at 30 Rock, where the progress made over the previous year was discussed. AES member Robert Auld gives a synopsis here:

http://www.aes.org/sections/ny/news12/news02_2012.pdf

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No problem, below are some more interesting links. BTW Jim Starzynski of NBC Universal, one of the heavies with regard to A/85's creation was one of my instructors back in my early days in pro audio...

FCC page on “Loud Commercials”:

http://www.fcc.gov/e...oud-commercials

NBC Universal/Comcast standards(also via Marc's link):

http://nbcuni.force.com/commops

Thread on Digidesign User Conference from top Audio guy at Discovery Channel:

http://duc.avid.com/...ad.php?t=157057

The Dolby Media Meter:

http://www.dolby.com...dia-meter2.html

The Dolby LM100 Broadcast Loudness Meter:

http://www.dolby.com...ment/lm100.html

Nugen Audio Vis-LM(I am demoing this using it for live-to-tape or live broadcast production, also linked by Marc):

http://www.nugenaudi...VST_AU_RTAS.php

Nugen Audio LM-Correct:

http://www.nugenaudi...ure_correct.php

Nugen Audio LMB(Batch File Processor):

http://www.nugenaudi...h_processor.php

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