SMPlayer is a free media player that supports various video and audio formats, including AVI, MP4, MPEG, and more. It comes with built-in codecs, which means it can play almost any multimedia file without the need for additional codecs. SMPlayer also offers advanced features like subtitle synchronization, audio and video filters, and playback speed control. Additionally, it allows users to save and restore settings for individual files and remembers the last played position of a file.