Thank you for one of the few measured responses in this thread. I mistakenly thought that a sub dedicated to the hobby and craft of let's play, filled with gamers, would welcome a guide on how to achieve the best video and audio for their viewers. I was extremely proud when I finally got the MediaInfo output from my vids to match the recommended specs. I was also quite worried when I saw a guide come across with bad info that was going to hurt people's quality without any benefit to them.

I don't know how else to say this, so I'll repeat myself. I am not telling anyone that their way is wrong. I am not qualified to make that call since no one has posted the specs for their upload video for me to see. YouTube is the one telling them they are wrong, not me. I didn't write their spec. You want to keep doing things your way, I fully endorse it. Just don't try to tell me that the best isn't worth the time, because that is scrub mentality.

To answer your question, intraframe codecs, like MJPEG, capture every frame as a separate image. This means that if you cut the video, it does not matter where because each frame is it's own image and is totally separate from all other frames.

Contrasting with this is an interframe codec, like h.264, which uses a GOP (group of pictures) for compression. GOP works by having a keyframe (I) every so often with intermediate (B) frames in between. Example: with a single keyframe and a GOP of 30, there are 29 intermediate frames between each keyframe which only contain the difference from the keyframe. This is much harder on your cpu to edit because when you make a cut, your cpu has to reconstruct that frame on the fly before it can cut it and it also has to shift all of the keyframes downstream to keep the GOP structure in alignment.

All of this extra cpu work is not necessary and your capture file will edit faster and with less cpu if you use and intraframe codec like MJPEG or YV12 (RTV1 is garbage and not recommended). Hope this answers your question.