I have several video files in .mp4 format. One has the visual, the other has the sound. These files are the exact same length. I looked into combining in VLC through convert/save but I get errors (and I can't select a destination to output to). I can convert the .mp4 audio into audio formats if that helps me. I do have some ways to combine (for example I have Premiere Elements) but I'm worried that will mess with the visual video quality when all I want to do is convert 2 files into 1. Add audio to video. It seems simple but VLC doesn't seem able to do it. All the VLC guides I found basically ended at "Convert/Save" like it would just work... and it doesn't work for me. My output folder is "Multiple Files Selected." and then if I click to convert anyways, I get the error. Anyone got any other ideas that don't take too much effort? I'm not good with code or anything but if command prompt can do it or there is a program you know of... I'd appreciate any suggestions.