colony nofi
03-19-2009, 10:46 PM
Right - o.
I swear I'm going to write a book about this one day...part trying to clarify standards, part the journey to find out the information.
So, I'm working on a high profile free to air HD channel launch here in syd at the moment... and coming up against it in regards to standards.
Generally speaking, in Australia we use OP48 for audio levels / in and out times for commercials (and in most cases, promos) - which is (relatively) easy to understand (or at least understand its "spirit" - its also VERY easy to abuse OP48, and I don't think there is a commercial going to air in australia that doesn't. For more info on that one, go grab the OP48 standards pdf over at freetv. Its all in the details regarding compression...hilarious.)
Right, ok. So anyway.
Generally speaking, standard def free to air goes out at -10dB peaks, (sometimes -9....) with +3 peaks on a VU calibrated to -20dBFS (although i'd say 50% of mixes are no longer checked on VU's). I've personally had mixes checked by people looking at meters on digibetas going "yeah, thats about right" - even when they are PINNING the -10dB peak.
Cool. So, you get to a point now where commercials are pretty much peak limited after (heavy) buss compression(often multiband) to end up with levels not unlike a foo-fighters CD, only 10dB down. Almost "mixed" by the buss compression / limiting.
And sometimes that works, and often it doesn't, but its what the producers like. And I guess that is for a separate discussion.
So now (with 12 frames of audio black at top and tail, 6 for payTV) you pretty much have a picture of audio for commercials / promos in australia - for Standard Def.
Along comes High Def - and surround.
And does ANYONE actually know whats going on? :)
So, I've been mixing quite a few surround promos lately - and its actually been great fun. But I still have yet to see a piece of paper with the standard for audio in front of me.
However, the ONLY levels I have ever had to check are thru using the dolby media meters - making sure that the "infinate dialog" level is at -27 for the duration of the promo / ad. (this uses the ITU-R BS.1770-1 algorithm)
I frequently deliver audio with peaks (short) well above -10dB, and its never bothered anyone. And actually sounds great, cause I don't need to use ANY buss compression or limiting. Its all about the mix. Oh yeah. I actually get to mix again rather than just push everything harder into the mix buss until it audibly breaks.
This is going to change. I can hear it happening already - especially in promos with no voice over (and people playing tricks with measured dialog levels by putting NOTHING in the C etc etc.)
So - now to some questions and a few more thoughts.
Has anyone (in australia first, but also I'd love to know what is happening in the rest of the world...nat geo surround mixes have gone to asia from my place and I've never heard much back) - got any other pieces of information on metering for HD surround content for promos and commercials - especially guidelines on maximums etc. Or is it really and truely up to our better judgement and a simple LEQ level?
In the last 3 or so months I have been asked by stations to mix this way.
Dial / Voice over ONLY in the Center. NOTHING ELSE.
L / R / Ls / Rs / Sub for sound effects, atmos and music.
Ensure Ls / Rs is a different signal to L / R for the most part (ie, use delays, verbs etc to ensure this)
Are others seeing this - and WHY?
Well - I can tell you one thing. I just got asked to deliver a mix for this new channel ONLY in surround. NO stereo mix.
What is going on here? And how are they doing it? The HD channel will also be broadcast in SD. So how exactly are they "creating" their stereo mix from my surround mix, and how are the levels of this going to stack up against other OP48 based commercials and promos (which the channel will definately still have!)
I am gob smacked. I am on / off the phone about this with various guys I know in pres and audio here, and I still don't have an answer. I'd love to at least be able to "mimic" what they are doing to fold down my mix so I can check it as it comes.
So bring forth your ideas, discussions etc.
Hopefully at the end of this process there will be a set of clear information, guidelines etc for people both in australia, and perhaps overseas (given the sharing of content that is happening more and more these days) that can be collected here for reference.
And to help some great sounding mixes.
Cheers all. I look forward to gaining more knowledge...
(Any ideas where else I should maybe post this????)
Brendan Woithe.
I swear I'm going to write a book about this one day...part trying to clarify standards, part the journey to find out the information.
So, I'm working on a high profile free to air HD channel launch here in syd at the moment... and coming up against it in regards to standards.
Generally speaking, in Australia we use OP48 for audio levels / in and out times for commercials (and in most cases, promos) - which is (relatively) easy to understand (or at least understand its "spirit" - its also VERY easy to abuse OP48, and I don't think there is a commercial going to air in australia that doesn't. For more info on that one, go grab the OP48 standards pdf over at freetv. Its all in the details regarding compression...hilarious.)
Right, ok. So anyway.
Generally speaking, standard def free to air goes out at -10dB peaks, (sometimes -9....) with +3 peaks on a VU calibrated to -20dBFS (although i'd say 50% of mixes are no longer checked on VU's). I've personally had mixes checked by people looking at meters on digibetas going "yeah, thats about right" - even when they are PINNING the -10dB peak.
Cool. So, you get to a point now where commercials are pretty much peak limited after (heavy) buss compression(often multiband) to end up with levels not unlike a foo-fighters CD, only 10dB down. Almost "mixed" by the buss compression / limiting.
And sometimes that works, and often it doesn't, but its what the producers like. And I guess that is for a separate discussion.
So now (with 12 frames of audio black at top and tail, 6 for payTV) you pretty much have a picture of audio for commercials / promos in australia - for Standard Def.
Along comes High Def - and surround.
And does ANYONE actually know whats going on? :)
So, I've been mixing quite a few surround promos lately - and its actually been great fun. But I still have yet to see a piece of paper with the standard for audio in front of me.
However, the ONLY levels I have ever had to check are thru using the dolby media meters - making sure that the "infinate dialog" level is at -27 for the duration of the promo / ad. (this uses the ITU-R BS.1770-1 algorithm)
I frequently deliver audio with peaks (short) well above -10dB, and its never bothered anyone. And actually sounds great, cause I don't need to use ANY buss compression or limiting. Its all about the mix. Oh yeah. I actually get to mix again rather than just push everything harder into the mix buss until it audibly breaks.
This is going to change. I can hear it happening already - especially in promos with no voice over (and people playing tricks with measured dialog levels by putting NOTHING in the C etc etc.)
So - now to some questions and a few more thoughts.
Has anyone (in australia first, but also I'd love to know what is happening in the rest of the world...nat geo surround mixes have gone to asia from my place and I've never heard much back) - got any other pieces of information on metering for HD surround content for promos and commercials - especially guidelines on maximums etc. Or is it really and truely up to our better judgement and a simple LEQ level?
In the last 3 or so months I have been asked by stations to mix this way.
Dial / Voice over ONLY in the Center. NOTHING ELSE.
L / R / Ls / Rs / Sub for sound effects, atmos and music.
Ensure Ls / Rs is a different signal to L / R for the most part (ie, use delays, verbs etc to ensure this)
Are others seeing this - and WHY?
Well - I can tell you one thing. I just got asked to deliver a mix for this new channel ONLY in surround. NO stereo mix.
What is going on here? And how are they doing it? The HD channel will also be broadcast in SD. So how exactly are they "creating" their stereo mix from my surround mix, and how are the levels of this going to stack up against other OP48 based commercials and promos (which the channel will definately still have!)
I am gob smacked. I am on / off the phone about this with various guys I know in pres and audio here, and I still don't have an answer. I'd love to at least be able to "mimic" what they are doing to fold down my mix so I can check it as it comes.
So bring forth your ideas, discussions etc.
Hopefully at the end of this process there will be a set of clear information, guidelines etc for people both in australia, and perhaps overseas (given the sharing of content that is happening more and more these days) that can be collected here for reference.
And to help some great sounding mixes.
Cheers all. I look forward to gaining more knowledge...
(Any ideas where else I should maybe post this????)
Brendan Woithe.