GSM Player

In mid-2004, I ported the GSM RPE-LTP (also called GSM Full Rate) audio codec, which has been used in mobile phones, to the Game Boy Advance. Now you can use your GBA as a portable music player, with up to 150 minutes of Good Sounding Music on a 256 Mbit flash cart.

From mid-2004 to mid-2019, GSM Player for GBA went unmaintained, and changes to popular GBA homebrew toolchains rendered it unbuildable. This repository ports the application to a more recent version of devkitARM.

Building a ROM

1. If building from source:

   make build/allnewgsm-bare_mb.gba
   padbin 256 build/allnewgsm-bare_mb.gba
   

2. Convert audio files to GSM at 18157 Hz (a nonstandard rate; see docs/lying_to_sox.txt for how to force this in SoX and FFmpeg)

3. Pack them into a single GBFS file using gbfs included with devkitARM tools: gbfs gsmsongs.gbfs *.gsm

4. Concatenate the player and the songs.

   • On Windows: copy /b build\allnewgsm-bare_mb.gba+gsmsongs.gbfs allnewgsm.gba
   • On UNIX: cat build/allnewgsm-bare_mb.gba gsmsongs.gbfs > allnewgsm.gba

Controls

To control the player:

• Left: Previous track
• Right: Next track
• L: Seek backward
• R: Seek forward
• Select: Lock other keys
• Start: Pause or resume

Copyright 2004, 2019 Damian Yerrick