Avidemux Forum

Avidemux => Main version 2.6 => Topic started by: BG Davis on July 23, 2019, 10:28:37 PM

Title: Does 'copy' with mp4 muxer degrade image quality?
Post by: BG Davis 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!
Title: Re: Does 'copy' with mp4 muxer degrade image quality?
Post by: eumagga0x2a 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.