More and more people are beginning to use MKV files nowadays. However, most media players, such as iPods, iPhones, and PSPs, cannot play MKV videos, which causes a lot of frustration for many users. Therefore, this tutorial aims to explain what MKV is and how to convert MKV files into MP4 or MOV formats so they can be played on devices like iPods, iPhones, and other incompatible players.
iPods and iPhones do not support playing MKV files directly, but they do support MP4 and MOV video formats. So, we can first convert MKV videos to MP4 or MOV format. This process should be fairly quick.
http://www.convert-video-dvd.com/guide/how-to-convert-video-to-avi-mp4-flv-m2ts-3gp.html