So, we had some great discussions in #postchat (5/28/2014 Transcript here: https://storify.com/EditorLiam/postchat-all-things-audio-w-michaelaudio) regarding the use of keyframes for volume automation in the NLE and how it is received via OMF/AAF to ProTools (or other DAW using OMF/AAF). Also, when to use fades vs. keyframes and how clip gain plays into that. I’d like to expand on all of that just a bit.
All the major NLEs will translate fade information reliably through OMF or AAF (I’ll explain the difference between these formats in another post). First thing to realize is that each NLE treats gain (volume) differently. I’ll briefly summarize here:
Avid (Media Composer)
MC uses clip gain as well as keyframe automation, which both come through the OMF/AAF non-destructively. The newer versions of ProTools use clip gain as well, which works exactly like it does in Avid. (Older versions of PT used to convert clip gain to volume automation, and it could sometimes drive me crazy! Editor would cut a clip to apply clip gain with a crossfade, and I would get the crossfade AND the keyframed automation – it was bizzarre. Now, I get the clip gain the way it was intended and it’s beautiful!) This is why the workflow of applying clip gain and using crossfades is so solid. It is less “audio guy” like, but it’s a great workflow from Avid to PT, and I’ve found myself using it more and more.
Final Cut Pro 7
FCP versions 6 and 7 use keyframe volume automation, but no clip gain. Very straight forward. If you’re on a version earlier than 6, your options are very limited. FCPX is a different animal, and there are great resources out there to help you.
Adobe Premiere Pro CC
Premiere is more complicated. You can apply gain to a clip, which is destructive. You can use clip gain right on the track to add up to 6dB, and you can also keyframe on the track (same as in Track Mixer). Clip keyframes will translate via OMF, and they can be smoothed with crossfades. Even though the interface may show a sudden jump in gain, the clip gain comes before the crossfade and is actually smoothed out by it. If this sounds confusing, please leave a comment below. Much more information is coming on this topic.
The use of keyframes as fades
It is common practice for editors to use keyframe volume automation to ramp up the audio at the beginning of a clip (music, NATs, etc.) and to ramp it down before the end of the clip. If this is your workflow, I can’t really say that it’s wrong… But, if you send all of your projects to audio post, I can tell you that the person receiving your files would probably prefer to have a cleaner timeline. One reason for this is that ProTools will create volume automation between the clips, essentially keyframing the entire track. So if you’re using keyframe data as fades, then the track will have a zero volume (negative infinity) between clips.
Also, in ProTools we aren’t usually looking at the volume automation, so you may have already pulled the music out with volume automation, but we still see the clip on the timeline for another five seconds. Basically, it gives a better visual representation of what’s really going to when you use fades as fades and volume automation as volume automation.
So far, I’m sure there hasn’t been any compelling reason for some of you to stop using keyframes in place of fades, and that’s okay. It’s not one of my most passionate topics. I personally think it’s easier in the NLE to use fades and if you try to get used to it, you may fall in love with that workflow. If you’re not married to either process, use the fades. There’s a real time and place for keyframed volume automation and getting comfortable with it will greatly improve your mixes. If your comfort with keyframes means that I have to delete a few when it comes to me, then so be it.
Thanks for reading, keep cutting, and please find me on Twitter: https://twitter.com/MichaelAudio