questions about cutting .mkv videos with ffmpeg and mkvtoolnix

[aaajan]

Hi Everyone

I want to cut parts of many 1080p and 4K .mkv videos, I have some questions:


1. Is cutting part of .mkv video with ffmpeg 100% lossless ?


2. Is this command correct for video cutting process ?

ffmpeg -ss 00:05:10 -i "video.mkv" -t 50 -c copy -avoid_negative_ts make_zero "part.mkv"


3. If ffmpeg is 100% lossless when it comes for cutting video part then that's more than enough for me,

but if not, can mkvtoolnix use a lossless method ?


Thank you !

[butterw]

1. Yes. Cuts on keyframes only though.
2. Yes.
3. Yes.

[aaajan]

1. Yes. Cuts on keyframes only though.
2. Yes.
3. Yes.

Perfect ! Thank you !

[aaajan]

Is mkvtoolnix only a ffmpeg GUI or does it have its own extensions ?

[butterw]

mkvtoolnix isn't a ffmpeg GUI, it's based on mkvmerge.

[aaajan]

mkvtoolnix isn't a ffmpeg GUI, it's based on mkvmerge.

OK. Thank you again !