Do you ever see one of your news stories or promos go out and realize loudness wasn't checked or corrected properly?Even if you have hardware-based audio compliance sitting on your output, issues with loudness can still arise. Watch this webinar replay Loudness for News and Promos, from Emotion Systems to discover how to implement more reliable and consistent loudness monitoring and correction.
Rich Hajdu:
Welcome to the webinar on loudness for news and promos. It's a big issue because a lot of people do news segments and the audio goes out to the playout server and it's not really loudness controlled.
I'm Rich Hajdu with Media Technology Group. MC Patel, the CEO of Emotion Systems, is going to be doing most of the presentation. We invite you to use the chat to send us questions and we'll answer them.
MC, the issue is that loudness for news and promos is not regulated in many instances because people don't have time to check the loudness when the news clip is edited. So it goes to the playout server and then it goes directly to playout. When it's time goes through a playlist and all that. So there is a loudness corrector at the output of the station. Why isn't that enough?
MC Patel:
The best thing is for me to quickly explain loudness. Now, most people will be familiar with it, but I'll explain it very shortly and succinctly, and that will help you understand why we do the file-based loudness correction. Historically, ever since television has been around, we have used peak-based measurement. What we basically do is say, What is the loudest or the highest peak in television? That's integrated in different countries at different time constants. In the US you guys use VU. In Europe, we use PPMs, but fundamentally what we say is that the sound shall not exceed a certain peak. In the old days, the reason for that was that in NTSC, the audio sat right at the end of the chroma subcarrier, so if the sound got too loud, it interfered in the transmitter and distorted the color.
That's where the peaking came about. As you know, in the seventies, people discovered that whilst you weren't supposed to exceed a peak, if you stayed very close to it, your commercials could be very, very loud, which is how the loud commercials came about. Over the years, people got fed up with it and said, we want some balance in the content, we want dynamics, but we also want to make sure there aren't sustained bursts of loudness. So the new standard called program loudness came about - in America it's called the CALM Act, but the standard is ATSC A/85. It said that the average level of a piece of content may not exceed a certain amount in LUFS. It's minus 24 in the case of the US, and then the second parameter that's important is the true peak. So the true peak may not exceed minus one or minus two, which varies depending on countries and standards.
When people used to mix to peaks, it was easy. They could see a peak on their PPM meters, and they came along and said, Yeah, I've got my audio right. When you have to measure to average level, that's kind of hard because you don't know what the average is till you get to the end. So when all this came about, there were a bunch of hardware correctors that you could put on the output of your master control and say, All the content that I've been producing for all these years is great. And the hardware corrector will take care of the loudness. Now, remembering that the average is what matters, the hardware corrector doesn't know when a program has begun and when a program has ended.
So the hardware corrector is saying, Over the last few seconds, whatever I've seen, I'll keep it very close to minus 24. So if you have a few seconds of silence, it says, Oh, dear, my average is going to fall below minus 24. It will raise the gain of that. And if you have a lot of very loud noises, it lowers it. Now that's modulating the audio, and that can cause problems.
If we go back to the promos and the news, the important thing that Rich said is that in a promo, in a local edit suite, you may not have the loudness measurement capability, or that people still mix with their ears for promos or anything. And one of the nice things is if you mix with your ears and you've been trained, you will naturally mix to 24, or in Europe we think it should be 23, or thereabouts. So the mix will be good.
And that's the other important thing: If you spend time creating a mix, you don't want to destroy it in the correction process. For news, unfortunately, as we know, the news comes in, you've got some background noise. If you're by a freeway, it will be really noisy background. If you have a quiet area, it could be really quiet. Then you have the people talking. And you're not sure what the levels are going to be, when it comes there and it gets edited. And as Rich so rightly said, there isn't time to take care of that. So what you're relying on is the hardware processor to take care of it. Am I'm making sense so far?
Rich Hajdu:
Yeah. So the hardware processor isn't really set up to do that. The question is, I'm editing news and it's fast-paced, I don't have time to manually intervene and check audio levels and all that. What's an elegant solution to do that, that is settable, repeatable, and reliable? What's the solution?
MC Patel:
There are a number of approaches. You can use a plugin in the edit suite, but as we already said, we don't want to do that because the focus should be on getting the right piece of the video there and out. When we approached this problem, our initial focus was commercials. A lot of people came up and said, Hey, we don't want to be fined. And the creative mix was important. A lot of the
