What is a good way stream copy lossless mkv or mp4 files?

[GAP]

I am looking for a good way to cut and stream copy lossless .mp4 and .mkv files without re encoding the files. What are some good methods that will allow me to do just that?

[SeeMoreDigital]

Stream to what. Not sure what you mean?

[StainlessS]

Perhaps Direct Stream Copy was intended.

[GAP]

That was what I meant. I guess I should made that clear but I wanted to direct stream copy the video without reencoding.

[stax76]

use mkvtoolnix

[SeeMoreDigital]

......I wanted to direct stream copy the video without reencoding.Into another container or to an elementary stream?

[butterw2]

You'll need to cut on keyframes.

[GAP]

Into another container or to an elementary stream?

The former mostly. I wanted to try to do the latter but I know Virtualdub2 cannot really do that without changing settings. As for the latter, I would like that before I convert it to something else.

You'll need to cut on keyframes.

I will try that. I just need to find a program to do that.