SwarmNSF is a Game Boy Advance NSF player. Instead relying on the DMG/CGB-compatible channels to try to mimic the NES sound processor, this is an all-software implementation running on the ARM CPU.
The player currently supports the 5 built-in sound channels of the NES, and only NSF files with at most 32kB ROM, since none of the ROM banks will move around during playback allows for certain optimizations that otherwise wouldn't have been possible.
The output of the emulation code is a stream of 8-bit unsigned mono PCM data at 32768 Hz, which is played back using one of the GBA's DMA sound channels.
Bandlimited synthesis is used for the two pulse wave channels to try to eliminate the worst aliasing artifacts.
The first 5 bars show the output levels of the NES audio channels, while the purple-ish bar on the right shows how much of the GBA's CPU time that is consumed by the NES CPU+APU emulation.
Up/Down - Previous/Next song
Left/Right - Previous/Next sub-song
SwarmNSF - A Gameboy Advance NSF player (xpmck)
SwarmNSF: An NSF player for the Gameboy Advance (Game Boy Advance Homebrew) (RY0G4 _)