When I drag files from my Sony camera's card, they are .MTS files, with simple numbering from 00 up.
When I use the Sony software to Import from the camera, they become .m2ts files, with different, much longer filenames (based on date and time), and there are accompanying .cmuprops files. The .m2ts files lose their original creation date and time.
The .MTS and .m2ts files have exactly the same file size.
The .m2ts files seem to play a little smoother in my timeline. (Maybe because of the .cmuprops files, which aren't imported into Premiere, but maybe Premiere sees them anyway?) The .MTS clips choke / stutter at dissolves, not all the time, but fairly often.
I do A LOT of file backup, so I pack-rat save both versions, .MTS and .m2ts (and the .cmuprops)
Is this crazy? Should I only deal with and save the .m2ts versions?
Can I freely change the file extensions if I want to, because it's the same exact thing? (Not that I'd want to, but maybe.)
I tried changing .MTS files to .m2ts, and changing .m2ts files to .MTS
Both played OK in the timelines after the file extension renaming. I could not recreate the stuttering at dissolves with either format in the simple comps I created.