[ This article was first published in the February, 2010, issue of
Larry’s Final Cut Pro Newsletter. Click here to subscribe. ]
I was getting my computer ready to do a presentation recently at the LA Final Cut User Group, when Andrew Balis walked over and asked: “Larry, I see you’re using non-standard audio in your sequence.”
I gave him a blank look and asked: “What?”
Andrew said: “See that green line at the top of your audio clip in the Timeline? It means that the sample rate of your audio clip does not match the sequence settings of your Timeline.”
Well, clearly, I have not been paying attention, because I’ve seen those green lines for years and never, once, figured they meant anything.
But I know that this audio was recorded at 44.1 kHZ, while the Timeline is set for 48 kHz, so I went to Sequence > Settings > General and changed the sample rate in the lower right corner to 44.1 kHz and… POOF! No green lines!
OK. Time for some homework.
Although FCP allows both 44.1 kHz and 48 kHz audio on the timeline at the same time and plays them both in real-time, when it comes time to output or export, any audio that doesn’t match your sequence settings gets rendered to match. This is not necessarily evil, but it can be avoided and takes time to render. And, for sample rates lower than 44.1 kHz, this re-rendering can affect quality.
In general, you want your sequence settings to match the sample rate of the majority of your audio. In this case, my entire sequence had music that was recorded at 44.1 kHz, so it made no sense to have my sequence settings at 48 kHz. Podcasts and pre-recorded music are other examples of 44.1 kHz audio.
Thanks, Andrew, for pointing this out. I’m now paying much closer attention to little green lines.