I am planning to get a 5.1 Music system. My usage will be to play songs from my 3.5mm jack mobile phone and movies from TV/PC. To get a 5.1 surround sound output, what would be required? Also how should be my input file? What modification to be done for input files to get the surround sound? I am from India.
a single 3.5mm jack is only capable of carrying STEREO sound (left+right channel). to get 5.1 on a computer speaker set you would need 3 of those jacks. one for front left/right. one for center/subwoofer. one for rear left/right. if we are talking a home audio system (not pc speakers) then you could use hdmi as well for pc hookup. keep in mind that your phone 3.5mm is incapable of any more than STEREO from its single port.
music files are typically recorded in STEREO so you will only get STEREO sound out of them. It is possible to have your front left and back left act as "left" and the same for the right to better utilize a larger speaker set but we are still talking stereo sound. while no doubt there are programs for conversion, you cannot get true surround sound out of a stereo feed. the only true surround sound music are the very limited number of music files recorded in such a way.
generally the only things (outside of specially recorded music) available in surround sound are movies and games.