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SK321
Inspiring
May 25, 2021
Question

Question About Previews

  • May 25, 2021
  • 2 replies
  • 796 views

I've been using Premiere Pro for over 15 years at this point, but I've never had great success with Preview files actually speeding up rendering. A couple years ago someone told me to switch my Previews codec to GoPro CineForm (YUV 10-bit) and then the final render would go faster if I used previews. That did seem to sometimes make a difference when exporting h.264 files.

 

Right now, I have a long video (2.5 hrs) that has lots of clips with Neat Video's Reduce Noise v5.1.0 plugin applied. These are 10-bit 4K clips from a Panasonic Lumix GH5 and Reduce Noise typically takes a while to render, so I rendered the entire timeline overnight to save myself time in the long run since I have to render it out for web, Blu-ray, and DVD. When I go to render out the timeline that now is showing all green across the whole thing, I choose "Use Previews" and I don't select "Use Maximum Render Quality", I notice that when it gets to the clips with the Reduce Noise effect, it's taking just as long to render those clips as it did to render the preview files. So, basically, it's re-rendering all of the clips with Reduce Noise on them that I've already rendered as previews. 

 

What am I doing wrong?

 

System Specs:

Windows 10 64-bit

64GB Ram

AMD Ryzen 3900X 12-core

RTX 2060

NVME 2TB system drive

NVME 1TB project drive 

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2 replies

R Neil Haugen
Legend
May 25, 2021

There's two ways to approach this.

 

The first is to do a render & replace to a good intermediate codec like Cineform, ProRes, or DNx when you've got something heavy like Warp or Neat Noise Reduction involved with a clip. That will "bake in" the processing to the clip, so that there's nothing about it to re-compute on exit. I do that quite a bit.

 

The other is to do their "smart previews" process, which works by using the same preview codec as your export will be. So within that, tell it to create previews (again, to the same-as-export codec) and then do check the "use previews" box on export. This may work much better with an intraframe like the three above mentioned codecs than with H.264/long-GOP codecs.

 

But often, the export is so much faster that you can export to the say Cineform that you used with your previews with "re-import" checked, then use that master file to make your H.264 deliverables, and still save time.

 

Neil

Everyone's mileage always varies ...
SK321
SK321Author
Inspiring
May 26, 2021
quote

There's two ways to approach this.

 

The first is to do a render & replace to a good intermediate codec like Cineform, ProRes, or DNx when you've got something heavy like Warp or Neat Noise Reduction involved with a clip. That will "bake in" the processing to the clip, so that there's nothing about it to re-compute on exit. I do that quite a bit.

Sounds like a better solution that what I've been trying, but of course the other benefit of doing a preview render is that I can play back those now rendered sections smoothly and also continue to edit and not have to re-render the whole timeline. Of course that's IF the rendered previews actually benefited me in reduced export time, which currently they are not.

quote

The other is to do their "smart previews" process, which works by using the same preview codec as your export will be. So within that, tell it to create previews (again, to the same-as-export codec) and then do check the "use previews" box on export. This may work much better with an intraframe like the three above mentioned codecs than with H.264/long-GOP codecs.

 

But often, the export is so much faster that you can export to the say Cineform that you used with your previews with "re-import" checked, then use that master file to make your H.264 deliverables, and still save time.

So, my issue with this method is that I have several different formats I have to export, so using the same codec for renders as my final export wouldn't apply.

I ended up doing your last suggestion and rendering out the entire video as a CineForm 10-bit file. It's fine, I just wish the previews worked because now if I end up wanting to make any changes, it's kind of a pain to not have to re-render the whole thing again.

 

Thanks for the suggestions.

Christian.Z
Community Expert
Community Expert
May 25, 2021

@Kevin-Monahan would be able to give the best insight on this.