Export WebM: Different frame sizes but same file size

[christina_7265]

Export WebM: Why does the file size remain the same with different frame sizes?

Hi,
I export the same video in the frame size 1280 x 720 and then again in 1920 x 1080. The file size (2MB) remains the same for all frame sizes. Shouldn't the file size decrease with smaller resolution?

[daapap · Accepted solution]

no, it shouldn't.

Bitrate is it: The lower the bitrate, the higher the compression. You can export 8k 4 MBit/s videos, but they will look like crap, while the same bitrate might be sufficient for 1280x720. The file size will not differ, 4MBit/s roughly equals .5 MB per second.

Compare it with mp3-files for example: 320 kBit is a larger file than 128 kBit but better quality, you would never ask why the track is still the same length 🙂

That is why so often people do not understand why their videos shot with their mobile phones look awkward although they are 4k: Simply because they might be compressed too much (and/or by a bad codec) to reduce file size.