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I noticed my Samsung TV stutters with every mkv file that has chinese subtitles in it. It doesn't matter if they are displayed or not, they only have to exist in the stream.

Is it possible to hide those subtitles or allow only specific languages so that the tv wouldn't even recognized others in the stream? open source software

Not without requiring transcoding. And even then the captions might still be included. You can use a program like tsMuxeR to remove the caption track completely, but then it's gone for any other device you might want that caption track.