Originally posted by RPG Hacker
The SPC plugin for Winamp, for example, had some special SPC settings where you could define the length of SPC files.
Foobar2000's Game Emu Player plugin defaults to 3:00 as well. I actually would heavily consider using GEP over VLC for .wav converting, as it's very simple and you can disable channels for things like oscilloscope visualizations, such as this.
Having the spc player check for loop information within the file is rather useless, as the sound drivers are unique (save for some games, for example SMW and Tetris Attack/Panel de Pon).
Another, more extreme way of .wav converting is to record the output from an actual SNES and edit the file to the desired output in Audacity. I haven't seen anyone do this with an SNES, but I do know of a few who do this with C64, VCS, and NES songs.