Question Regarding Constant Quality

General questions or discussion about HandBrake, Video and/or audio transcoding, trends etc.
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Snaptrap
Posts: 25
Joined: Sat Dec 05, 2009 4:27 am

Question Regarding Constant Quality

Post by Snaptrap »

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!
mduell
Veteran User
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Joined: Sat Apr 21, 2007 8:54 pm

Re: Question Regarding Constant Quality

Post by mduell »

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.
Snaptrap
Posts: 25
Joined: Sat Dec 05, 2009 4:27 am

Re: Question Regarding Constant Quality

Post by Snaptrap »

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.
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