ripping results in ~17GiB dropped from original file?

[bredboi]

when ripping a particular 4K disc i noticed that the output file is significantly smaller than what makemkv states (51.9 GiB vs 68.9). i verified the original file size by backing up the disc and checking the source m2ts file, and i also checked if this was a makemkv only thing by ripping with mkvtoolnix and got the same result. nothing mentioned in the output apart from empty forced subs

everything seems to be in order (it all plays fine all the way to the end, all audio/subs seem to be there) so im just wondering if theres some explaination as to the disparity? 17GiB seems a bit much to be container overhead or something like that.

[dcoke22]

Did you uncheck some audio languages? They can be fairly big, especially the lossless formats.