HandBrake

If I were to encode a video at QP 15, and then encode it again at the same value, would the quality of the video degrade each time it's encoded or will it maintain said quality no matter how many encodes are performed? Thank you!

Yes, lossy encoding will degrade with every subsequent encode. Each encode is trying to imperfectly reproduce the input, they have no idea what existed in prior generations.

Thank you. I've tried encoding a video multiple times, and it seems to stop compressing the size at a certain point depending on the video. That's why I enquired about it having some kind of image grading algorithm.