Web Distribution- Do We Need Measurement Tools Any Longer?

by Jun 6, 2017CMMA Blog0 comments

I began my career in TV and special effects. Everything we did was measured both visually and aurally. I prided myself on surviving the transition from analog to digital, knowing color space, black levels, and the transition from 0VU to -20db in audio levels as reference points for any content sent out for air. My first foray into Internet delivery started with building one of the first Microsoft encoding platforms for MSN. I noticed very quickly that all of my history and pride went out the door when I looked at the results of this content on the web. If you could get past the variable frame rate and low sample rate of the audio, I noticed that the content looked washed out when set up to color bars. It took an intern to show me that his video looked a little richer by adding contrast and increased color values outside of legal limits to make video look good on the web. The interesting thing is the intern had no training in color space, broadcast levels, or any understanding of the use of color bars and reference tone, he just knew it looked better. After a few heated discussions and feedback from our Internet customers, we adopted profiles that were not compliant for broadcast. Recently we have experienced the same transition in audio.

The web, in many ways, is the Wild West. I’ve personally measured hours of various audio content played from the web and the levels are all over the place. With much self-generated content making its way to the web in such places as YouTube, people can output at whatever level and quality they like. This can become a problem for professionals as broadcast levels are typically much lower and delivering a separate, louder mix may not be a possibility.

Recent developments in the audio industry have brought us tools for measuring loudness in a much more accurate way. These tools demonstrate audio loudness in LKFS or LUFS. By and large these terms are interchangeable with LUFS being a more current rendition. Starting in Europe and now being adopted in America, LUFS metering has become what could almost be described as the first universal standard for audio loudness metering with it becoming the law in many regions across the world. In America, we have the CALM Act to keep commercial loudness at bay.

Here at MPS, our audio team has been investigating this situation for the better part of five years. As a result, we have arrived at what we believe is a great solution for delivering content to broadcast legal audio levels while having a louder, more competitive spec for online. Compliance with the CALM Act requires a program loudness of -24LUFS and a peak level of -2dbtp. That’s an additional 8db of headroom or dynamic range compared to previous program levels which peaked at -10dbfs. Some material may benefit from this additional dynamic range such as movies or dramatic TV shows, but by and large, news, reality TV, and music may still choose to peak limit lower than -2 for a less dynamic audio experience. At MPS our audio team has chosen to work at a level spec that is louder to the CALM Acts requirements since the bulk of our deliveries are for web. Our online spec is -2dbtp and -16LUFS. What’s great about this is that content does not require re-mixing if used for broadcast. Simply normalizing the program audio -8db or to -10dbtp and -24LUFS would make the content broadcast legal. You could say that the same mix creates two deliveries. Pretty cool.

From a management perspective I have good and bad news. Bad news is I rarely see the use of scopes or measurement tools. The good news is how much money we saved by not having a suite of measurement tools in every production room.

Article Contributed by Brian Honey, CMMA Board of Directors