Free Online MKV to WV Converter

MKV is an open source container that can contain media data compressed with a use of different codecs. It has a lot of advantages over the legacy AVI container: it can contain audio tracks and subtitles in different languages, that can be switched without stopping the playback, file seek and rewind are very fast. Also the format is easy to edit, that is why audio and video data can be extracted effortlessly.

WavPack lossless audio compression. Note that, when converting .wav to this format and back again, the RIFF header is not necessarily preserved losslessly (though the audio is).