Caution

This sound driver is still heavily WIP and is not quite ready for use yet! You can expect I will begin adding API and usage documentation once things get more in a state where others could start using it. Please reach out if you're interested in testing :)

Kitty Advance

MIDI-based GBA sound driver supporting samples + PSG channels

Demos:

• Demo song: (Video) (GSF) (GBA)
• Hare Hare Yukai: (Video) (GSF) (GBA)

Features

• Reads directly from MIDI file
• Uses ipatix's HQ-Mixer https://github.com/ipatix/gba-hq-mixer to mix up to 32* sample voices
• Soundbank format similar to the one used in MP2k/Sappy. Currently supported:
  • Single sample instruments
  • Multi sample instruments with keymap
  • Drum kit
• Samples can be converted using wav2agb.
• Loop points using "[" and "]" markers
• Vibrato/LFO via CC 1 (Mod wheel). Uses triangle wave. Speed/depth not yet configurable. For DirectSound and GBC
• Velocity, volume (CC 7), and expression (CC 11) for DirectSound and GBC(except mid note)
  • Volume levels are based off of sqrt, so are more aligned with standard MIDI files and DAWs.
• Pan (CC 10) for DirectSound and GBC
• Sustain (CC 64) for DirectSound and GBC
• Set voice stealing priority (CC 33). Higher number means higher priority. If not set, or tracks are equal priority, then favour is ordered by descending track number (e.g, Track 1 has first priority).
• Pitch bend and pitch bend range via CC 20 or the standard RPN 0,0
• GBC channel support
  • Supports the 2 GBC Pulse wave channels, only by switching channel output via CC 4 (1 = Channel 1, 2 = Channel 2)
  • GBC Duty cycle change via CC 2 (0 = 12.5%, 32 = 25%, 64 = 50%, 96 = 75%)
  • GBC hardware envelope set via CC 3 (64 = center, lowest speed (0). 0 = downwards at fastest speed, 127 = upwards at fastest speed)
• Live MIDI input support by reading a buffer of MIDI commands in memory

(* practical maximum depends on mixing sample rate. e.g., this can go up to 48 in frequency mode 3, but only up to 16 in frequency mode 8, so TBD/needs more testing)

TODO

• TBD
• GBC Wave setting
• GBC Noise channel support
• Complete soundbank implementation:
  • GBC with ADSR envelopes
  • HQ Mixer synth instruments
• GBC software envelopes for duty and pitch
• Tooling soundbank creation
• Additional mixer features:
  • Lowpass filters per voice
• Support multiple players. (In theory it probably already works,