Have no idea which format you should pick up when you convert a BDMV folder? Check the comparison here:

Parameters MP4 MKV
Video Quality High Ultimate
File Size (Equal quality & length) Medium Large
Format Category Video Compression Method Video, Audio Container

(No compression, thus, no downgrade and larger file size)

Compatibility Works on almost every computer, phone, tablet, TV, and media player software Most phones cannot play MKV;

Some media player software like Windows Media Player cannot play MKV too

To warp up:

  • If your only desire is to play the video as easily as possible, pick MP4.
  • Try MKV if you’re pretty strict about the quality of the frames.