Why Render Unnecessary Audio Previews?

[Rowan!]

For years now, I've lived with Premiere Pro rendering "previews" of all the audio files in the entire timeline when I simply want to output just a short work area, but why? I don't get this behavior!

I'm working on a 90 minute film but when I export a short work area I have to either wait a massive amount of time for Rendering Required Audio Files that are not in the work area to finish or create a subsequence of that work area, which renders very fast (but that's a multistep workaround).

Image shows a 1 min 38 sec work area with about 75 audio clips to create previews of 2500 audio clips requiring an hour.

Seems like Rendering Audio Previews could be done in the background rather than waiting until the moment a quick render of a litle work area is needed.

I've lived with this weird, annoying, time-suck for years.

Anyone know why?

[Jeff Bugbee]

I'm trying to replicate this issue but I haven't been able to. What export settings are you using?

I've tried this and it renders only my work bar, and very quickly. 

[Rowan!]

Hi Jeff...

Where this happens is with File -> Export Media. Specifically...

In the Export panel, I select how I want it to render out, then only after I click Start does the modal window display the exceptionally long Rendering Required Audio Previews as shown in my original post. (Your screenshot of Sequence -> Render Entire Work Area is not where the issue is.)

The screenshot I've included with my reply here shows the rendering settings to answer your question about settings but I can tell you from past experience, it doesn't matter what the audio settings are.

I can understand PP needing to render out audio but why does it need to include thousands of audio files that are not part of the work area?? That's what makes no sense.

[Jeff Bugbee]

This is a guess: but are those clips you are rendering out part of much, much larger original files? For example, if you have an hour video, but only need 5 seconds. When you render, perhaps it has to render the entire file due to the source codec, or perhaps the destination one. Or it could simply be a limitation of Premiere. Like I said, I can't replicate this, but I'm not using the same files/codecs as you, which is why I suspect it may be something specific to those files.

[Rowan!]

I can tell you the video files are all image sequences (Blackmagic DNGs) and the editor linked the production audio files to each video file. But, as mentioned, if I make a subsequence of the work area, Premiere renders that out virtually instanteously, no problem. It's when the work area sits in the 90 minute timeline that it needs to spend an hour creating the audio previews, even if I'm rendering out only the video (audio off).

Once all these many previews are created then it does render out just as quickly from the timeline as it does from a subsequence of the same work area...and that's all I know. (I tested custom output vs Match Source and that also didn't matter.)

[Jeff Bugbee]

Can you give any more detail on these audio files? Are these 45+ minute audio files? Or smaller clips? Do they have a lot of audio effects added to them within Premiere?

[Rowan!]

I don't think they have any FX added but most are "merged" and the editor was using the multicam features to select the shot (but that would be for the video tracks, obvs). They're all production audio files, meaning the Sound Recordist recorded each clip for each shot, so they really short; most a few seconds long. None are more than a couple minutes but that's usual. 

Merged is what I see on most of the audio files because the editor linked the audio to the multicam video clips.