Moritz Bunkus - (Free)
MKVToolNix is a handy and powerful set of tools for easily creating and working with Matroska (.MKV) files.
MKVtoolnix is a handy application that helps you to work with Matroska - a multimedia container that allows to unite in a single file video, audio and subtitle tracks, taking the concept of mkvextract GUI but empowered with some additional features. The application lets you extract the audio, video and subtitles of MKV container, mix new audio tracks, videos or subtitles, convert videos and audios to Matroska (MKV) format, offering the possibility to choose the default audio or add more, and the same with subtitle tracks. In addition, you can retouch MKVToolnix quality and appearance of the video. MKVToolnix supports the many formats such as for video: 264, AVC, H.264, AVI, DRC, MP4, MPG, MPEG, M1V, M2V, EVO, MKV, OGG, MOV, RA, RAM, RMVB, VC1; audio: AC3, AAC, M4A, MP4, DTS, FLAC, OGG, MP2, MP3, MKA, TTA, WAV, WV and subtitles: SRT, ASS, SSA, USF, XML, IDX.