Modiac free MP4 to MKV Converter is a perfect and free MP4 to MKV video converting software that can convert MP4 video file to MKV format for playing or further applications. Meanwhile, users are able to customized all the audio and video parameters as they need through this MP4 to MKV converter. With advanced codec engine and super accelerating technology, it can provide fastest converting speed to convert MP4 to MKV with high quality. Furthermore, it is capable of converting more than two videos at one time or convert any video segment.