Manual:

"media_play(STRING* name,BMAP* target, var volume)
media_loop(STRING* name,BMAP* target, var volume)
Plays a movie or audio stream from a file to the screen or to a texture or panel. Media_play plays the stream once, media_loop repeats it until it is explicitly stopped. As many movie, sound or music files as supported by the hardware can be played simultaneously - for instance, to play two midi files at the same time you'd normally need two sound cards. All file formats supported by installed CODECs can be played with this instruction - .avi, .mpg, .divx, .wmv, .wma, .wav, .mid, .mp3, .ogg and so on, even some still image formats like .bmp or .jpg. "