Export is double the size using the same input settings

Hi guys, so I’ve been using shotcut for over a year and have learned loads using this awesome sofware, however rendering is definely where I get caught up, I;ve watched so many gobaldy gook tutorials on Youtube from folks supposed to be explaining how to export/ render which always end up to be crap and uninformative. So here is my question, I’ve taken a mp4 video into shotcut (2 hours long) 1.64 GB in size, all I have done is edit the length of it, nothing more. to 40 minutes, when I go and export with the same settings, on the Codec tab where it normally defaults to Quality 55%, I change that to 85% to maintain the quality and then export the file, it ends up at 3.64 GB. Can any body kindly enlighten me as to what I am doing wrong Thanks in advance. Regards David Ryan

Instead of export, you can try Properties > menu > Extract Sub-clip… (after settings your in and out points).

“Percent quality” is not an intuitive metric, hence the common confusion regarding it. 100% means lossless, which sounds like a good thing. However, the human eye can only detect variances up to around the 68% mark. Above 68% will burn disk space for quality improvements that the eye can’t even detect or appreciate (wasted space). The default of 55% is good enough for most projects. A common technique is to export a small portion of the project at 55% quality and only raise it if it isn’t good enough.