The original author, Hungarian Árpád Gereöffy, started the project because he was unable to find any satisfactory video players for Linux after XAnim stopped development in 1999.

After mpg12play v0.95pre5, the code was merged with an AVI player based on avifile's Win32 DLL loader to form MPlayer v0.3 in November 2000.

Two studies in 2007 and 2010 implemented hardware decoding for MPlayer,[9] including for specific mobile device architectures.

A variety of command-line parameters allows changing the appearance of the player, including -speed [number], -af scaletempo for changing audio speed while maintaining the pitch, -ss (start at ___ seconds), -sb (start at ___ bytes), -endpos (stop playing at ___ seconds), -novideo for only playing the audio track of a video, and -loop [number] for looping.

[12] MPlayer can play many formats, including:[13] MPlayer can also use a variety of output driver protocols to display video, including VDPAU, the X video extension, OpenGL, DirectX, Direct3D, Quartz Compositor, VESA, Framebuffer, SDL and rarer ones such as ASCII art (using AAlib and libcaca) and Blinkenlights.

[17] The main changes from MPlayer were improved pause handling, Matroska support, seeking, and support for Nvidia VDPAU; enabling multithreading by default; and the removal of MEncoder, the GUI interface, and various video drivers and bundled libraries, such as ffmpeg, relying instead on shared libraries.

[23][24][25] In January 2004, the MPlayer website was updated with an allegation that the Danish DVD player manufacturer, Kiss Technology, were marketing DVD players with firmware that included parts of MPlayer's GPL-licensed code.