My music file is about ~300 MB and ~4 hours long. I'd like to add a background image onto it to upload it on Youtube. The problem is, when I try a video rendering program (Kdenlive, Windows Movie Maker etc.) to do that, the output becomes massively big, like ~40 GB. I don't understand, why does merging procession of a 300 MB mp3 file and a 1 MB png file result such a huge file size like that? Does the rendering program render the background image again and again for every frame? Can't the whole video have just a single frame and an audio attached on it?

Is there another way to accomplish it?

1 Answer 1


Simple answer is yes - the Video frame is repeatedly encoded multiple times. There is compression - including frame-to-frame, but the single image frame is effectively duplicated numerous times. Try reducing the resolution for lower file size - if the quality of that image is not so important.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.