Author Topic: Does 'copy' with mp4 muxer degrade image quality?  (Read 260 times)

BG Davis

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Does 'copy' with mp4 muxer degrade image quality?
« on: July 23, 2019, 10:28:37 PM »
Hello,

I want to make multiple copies of an mp4 video, each one with a different sound track.
Using Avidemux, if I set Video Output to 'Copy' each time, will the quality of the video frames remain unchanged, or will it degrade slightly with each 'copy' operation?

Thanks!

eumagga0x2a

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Re: Does 'copy' with mp4 muxer degrade image quality?
« Reply #1 on: July 23, 2019, 11:06:22 PM »
While the very first stream copy generation may result in so called early (or leading) B-frames not used as reference for later frames being dropped, the content of all other frames should remain unchanged no matter how many generations. Absolutely.