I'm confused? I've not had any issues trimming files regardless of whether they are MKV files with no additional re-encoding or MP4 files that have been re-encoded using H.264. In both cases, the files are trimmed with no additional encoding. Maybe it's the differences in the software. What issues did you get when I assume you try to trim H.264 encoded content?I’m not compressing my rips any further beyond what’s on the disc, so that does make it more possible to trim the files at a later time if I ever have the tools. I wouldn’t have to start at square one and rip the disc again.