Virtual Headphone Surround from Stereo with Mplayer

Fun things to do with mplayer include upmixing stereo to 5.1 surround -- with the help of surround, sub, center filters -- to play it on your surround system and also downmixing 5.1 surround to play it on your headphones -- with the hrtf filter. Now another fun thing you can do is combine the two and upmix Stereo to Surround and then back down to Stereo to have some additional atmosphere for your headphone music: mplayer -channels 6 -af resample=48000,surround,center,hrtf

Enjoy