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4:2:2, GOP, Broadcast safe audio
Hi all,
I’m creating a TV ad for broadcast in the USA. There are a few things on a spec sheet that I’ve received which I don’t understand – I hope you can clear these up for me.
It says that HD video should be in 4:2:2 which I understand to be a colour space. If footage that I’m using wasn’t shot in 4:2:2, how do I convert it so that it is? Is this something that I can do within After Effects or Premiere Pro?
For SD submissions it mentions having a 9 frame GOP. The HD specs say ‘GOP structure not defined’. This is something I’ve never heard of. From Googling, I get that GOP stands for Group of Pictures, but I don’t know how this is something that I can alter or adjust in After Effects or Premiere Pro?
Lastly, the spec sheet says that average digital audio levels should be between -16dBFS and -20dBFS with high peaks between -10dBFS and -12dBFS and a maximum of three peaks per second. I guess you could call this “broadcast safe audio”. In After Effects or Premiere Pro, is there a technique for monitoring the audio to make sure it sticks within these boundaries? And what techniques do I use to adjust it if it’s off?
Hope that’s not too much of a ramble – any tips appreciated.
Many thanks,
Jonnie. -
2 Replies
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Jonnie –
Here’s a rundown on the 4:2:2 color space conversion – essentially, while you can make a 4:2:0 into a 4:2:2, you’re not going to gain anything in quality, since you’re stuck with the color information the clip was shot with.
https://blogs.adobe.com/VideoRoad/2010/06/color_subsampling_or_what_is_4.html
Quite a bit of the information in the broadcast specs can be ignored, at least from my experience. I’ve called production departments at several stations to which I’ve sent spots, and not one of them even knew what I was talking about, especially the GOP specs.
As far as audio goes, here’s more than you want to know – skip to the digital audio paragraph:
https://broadcastengineering.com/audio/managing-audio-levels
You may want to take a side trip to Audition or Soundbooth with your audio to check the peaks. Here’s a nice video on using Normalization to achieve the specs you’re looking for:
https://www.onlinevideo.net/2011/09/how-to-get-perfect-audio-in-adobe-premiere-and-audition/
Joe Bourke
Owner/Creative Director
Bourke Media
http://www.bourkemedia.com -
Hi Joseph,
Thanks a lot for this information – I’ll give it a good read over and if I have any questions I’ll post back up here.
I’m a little concerned that I’m out of my depth with this project as I’ve never produced a TV spot before (nor been involved in the production of one). Hopefully it’s not as complicated as a few other threads have made it out to be, but it certainly seems like it is…
Much appreciated,
Jonnie.
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