mkvtoolnix

Hi, Im wondering if you have remuxed a file, then later on want to edit the chapter or header in anyway, will the audio or video be affected? I have mkvtoolnix version.14.00 now, remuxed file is from version.13.00

My question is if you use mkvtoolnix and do not check of the option "no compression" and let it stay on the option "determine automatically"- for audio, video and subtitle (pgs) will the quality lessen / be lowered? Which means that it will not be a remux but become an encode. In makemkv there...