Video Export VBR 60% - not the same quality

Hi everybody,

I have here a video clip, which I placed together with other clips in a 53 seconds long video. I tested the compression settings for days and then applied them to a longer video (about 7 minutes). The longer video also contains the same clip, so I compared the same frames on both videos.
Source material: 3840x2160_25p 16:9 h264
Target material: 1920x1080_25p 16:9 h264
I have chosen my compression settings as follows:

Interpolation: Hyper/Lanczos
Codec libx264
Quality based (VBR) 60%
GOP: 13
B-Frames: 2
CodecThreads: 0

Now to my observation, which I can’t explain:
The frame from the 7 minute video looks worse than the frame from the 53 minute video. At absolutely the same compression settings with the same quality specification. Even when I rise quality to 85% in the 7-minute video the result looks worse than the 53-second video @60% while the filesize rises by factor 35. What am I doing wrong?

Since I am a new user, I can not put 2 Images in a post to show you what I mean…


My mistake - I realized that my project/time line settings in both projects differ. I reduced them to 720p in the 53 minute video in order to work faster (less ressources consumption). I assumed that these are just the preview-settings and the important settings are only the export settings. That was wrong.
After I have changed the project settings (timeline) back to 4k the result looks the same as in the short project video.

So maybe if someone else has the same issue. That cloud help.


Thank you for returning to report your resolution, and I am glad that you could get along!