DTS (Digital Theater Systems) is a standard home theater audio format developed in 1993 to compete with Dolby Digital. If used in your home theater system, it provides surround sound for 5.1, 6.1, and 7.1 setups. Compared to Dolby Digital, DTS uses higher bitrate, thereby offering superior sound quality.
Apple iTunes VLC Media Player File Viewer Plus Media Player Classic
M4B is an audio filename extension for AAC format, which is developed by Apple Inc. It is mainly used on podcast and audiobook files. Typically, M4B files contain audio and other metadata like images, hyperlinks, and chapter markers. M4B files are DRM copy-protected and can be opened on Apple iTunes and QuickTime Player.