High Quality Content by WIKIPEDIA articles! DivX Plus HD was launched in 2009 and is the brand name for the file type that DivX, Inc. has chosen for their high definition video format. DivX Plus HD files consist of high definition H.264/MPEG-4 AVC video with surround sound Advanced Audio Coding (AAC) audio, wrapped up in the open-standard Matroska container, identified by the .mkv file extension. DivX Plus HD files leverage and extend on Matroska`s ability to support multiple language tracks, subtitles, chapters, and additional bonus content.