To play MKV files, you'll need a media player that supports the format. Some popular options include:

ffmpeg -i input.mp4 -c copy output.mkv

Unlike other formats that compress and lose detail, MKV can store "remuxed" files—direct copies from Blu-ray discs that preserve every pixel of the original cinematic quality. The "All-in-One" Container: A single MKV file can include: