how mkv file to mp4?
['Run "VLC media player".', 'From main menu select "Media" > "Convert / Save...".', 'On "File" tab, click "Add..." button.', 'Choose you MKV file. ... ', 'Click "Convert/Save" button.', 'Select Profile: "Video - H. ... ', 'Click on the icon button that has hint: "Edit selected profile".']