bitrate, export

[Ferhan31950344bnz2]

Hello. In the export settings, I see the bitrate properties at their highest settings. 
The export video is shown as 16 gb, but the export results later make the video 8 gb. 
Why could this be?

[Averdahl]

16BG is just an estimation, that´s why you can get another file size when you export.

[Mike Dziennik]

Your H.264 encoder is set to VBR with a target of 50Mbps. That is very high for HD video, you've basically given it more data than it needs to achieve a high quality result. If this is a 'master' file then you shouldn't be using H.264 because it's lossy...use something like ProRes or DNXHR instead.

If you're just exporting a high quality viewing copy then you can use a much lower bitrate. Premiere's 'High bitrate' setting is around 15Mbps by default.

[Ferhan31950344bnz2]

I appreciate your interest and response. But I know this information. I am making a documentary. There are people who watch my work on Android TVs. That is why I am getting H.264 export. However, in my last few works, the exports I have received are much smaller in size than shown. On another computer, the same file is in the same size as shown. I wanted to know the reason for this.

[Mike Dziennik]

It's the nature of VBR: the encoder changes the bitrate based on the content.

If your documentary was just a single still frame for 1hr...you cold crank your target bitrate right up but you'd still end up with a small file because there is nothing changing frame to frame and so very little data is needed to encode it.

A 1hr video of waves crashing on a beach (using the exact same encoder settings) will give you a much bigger file  because more data is required to reproduce the complex images.

Premiere doesn't know what the content of your video is until you actually encode it, so it makes a guess based on 'average' content. But if your doc has say lots of stills, or lots of interviews with a locked off camera, then less data is required to reproduce that...so your filesize will be smaller than the estimate.

[Ferhan31950344bnz2]

Thank you again for your interest. I understand what you are saying.
 There is something I do not understand.
 When I export my same project from another computer, 
I get an export file much closer to the Premiere estimate. What could be the reason for this?

[Mike Dziennik]

Are you 100% using the same settings on the other computer?

The other one could be using software encoding which might yield a different result. Post screengrabs of all the encoder settings on each computer (and the resulting file sizes) and maybe we can pin it down.