Why Preview File Format default is I-Frame Only MPGE in Adobe Premiere?

[fernando alves]

I came from Final Cut 7 and I allways transcode my material to ProRes and setup my sequences as Apple ProRes. And I never understand the I-Frame Only MPGE when I migrated from FCP 7 to Premiere. Why Adobe Premiere sequence default codec is MPGE I-Frame? By the way, I have never seen any codec called MPGE I-Frame? 

Usualy I get this sequence setup when it cames from an assistant that don't know my workflow. I hate this setup. Or am I missing something on this? Shoud I give a chance to Preview File Format >I-Frame Only MPGE?

Thanks a lot.

[Meg The Dog]

Premiere treats the preview files that get created by rendering as disposable previews that you use only as temporary stand-ins to let you view your edit in real time. You'll choose the actual output file format when you export.

(If you choose Match Sequence Settings on Export Settings panel, it will choose the settings you have set for the preview).

MPEG I-frame is a very low bandwidth format that retains ease of editing, so for the purpose of providing only temporary files, it is a good choice. The I-frame indicates it is an intra-frame codec (like ProRes) as opposed to MPEG which in inter-frame, using a GOP structure.

If you want to make use of your preview renders as final output files, you can easily set the Sequence Settings to create the preview files in that format:

You can easily change the Preview settings of a sequence at any time. You will, of course have to re-render and previews that were done prior to the change.

You can also set up custom sequence settings presets that include your preferred format for the preview files:

MtD

[fernando alves]

Another doubt. Why when you use I-Frame Only MPGE the timeline bar is allways yelow? And if use the right clip files codec it won't have any color bar in the timeline.

[Meg The Dog]

The red/yellow/green bars are estimates from Premiere as to whether it can play the material back in real time without glitching. What color bar you get depends a lot on the horsepower of your computer, see this blog post:

https://theblog.adobe.com/red-yellow-and-green-render-bars/ 

Personally, I convert everything to ProRes and edit with the preview set to ProRes as well, since I am Mac based. Then when I output, I check the box for use Previews in Export which saves time.

but everybody works in the way that is best for them.

MtD

[ah_photo]

I agree with MtD, whatever works best for you. That said, ProRes (or DNx/Cineform) is superior to MPEG ALL-I for raw editing performance.

Personally don't re-use my previews for export and don't really need the "best of the best" quality when generating previews, so I tend to just use resolution-matching ProRes 422 Proxy as my preview format in most cases. Good for performance, yet still efficient on space compared to the higher end ProRes flavors.

But yeah, don't feel pressured to use MPEG just because it's the default. I honestly have no idea why it is, maybe it's because it's (I'm assuming) a more space efficient option and Adobe didn't want people freaking out as to why their drives were filling up so fast? Beats me!