Video editing newb here, trying to understand it better.
I downloaded a fireplace-type video from YouTube in mp4 format that is 12 hours in length and 55.2 GB in size.
I loaded it in Shotcut, converted so I can edit it, trimmed it down to 10 hours and exported as mp4. It is now 70 GB in size.
Why?
It is perfectly normal for an exported video to be larger than the source, even after trimming. The file size is primarily determined by bitrate (the amount of data processed per second), not just the video’s duration.
When you export, Shotcut likely uses a higher bitrate than the original YouTube file to ensure no quality is lost during the re-encoding process.
But under exports, advanced, you can set the exact and get smaller export file size.
Thanks for the reply. So I tested the export options under ‘View > Export’ and used the ‘YouTube’ preset to export a 1-hour version. That is 3GB. I exported a second 1-hour version with the default settings which resulted in a 2.5GB file size. Not sure what I learned here lol
The YouTube preset adheres to YouTube’s published guidelines. But most people know YouTube accepts way more than what the guidelines suggest. It seems they published something for people to read because that is better than nothing and wondering why a certain upload is not working. Still, the guidelines are a decent starting point. So, the Shotcut defaults are based on that but relaxed a little (longer GOP) to reduce size because people are also sensitive to upload time.