Hi there, I'm new to these forums, looking for folks who might know about GBA homebrew toolchains from 2003.
I came because I'm working on trying to reverse engineer the ROM-building process for MusicPlayer Advance, Neimod's 2003 WinAMP-inspired homebrew for GBA. I know there are better-maintained music player solutions like GSMPlayer, but I find MPA to be charming and the Windows software for converting audio and packing it into the ROM still works!
The (somewhat tedious) process goes like this:
1. Convert audio files to PCM (WAV) with specific bitrate and sample rate
2. Use MPAWRITE.exe to convert PCM to "MPA" format (mystery compression), one file at a time.
3. Use MPAWRITE.exe to insert a playlist of MPA format tracks into the music player ROM.
I'm a web dev and I want to build a web app that automates this whole process, so you upload a list of songs and it spits out a MusicPlayer Advance ROM with your music included.
I already successfully spec'd the format used for packing MPA into the ROM, but I haven't figured out what compression is used to convert PCM to the MPA format. I figured folks familiar with early GBA homebrew toolchains might be able to provide insights. Were there common types of file compression, or common audio file types, used for homebrew games at the time?
I have attached a folder with all the MusicPlayer Advance files, plus a text file where I describe the spec of the MPA audio storage in the GBA ROM, and also a before/after sample of PCM converted to MPA.
I came because I'm working on trying to reverse engineer the ROM-building process for MusicPlayer Advance, Neimod's 2003 WinAMP-inspired homebrew for GBA. I know there are better-maintained music player solutions like GSMPlayer, but I find MPA to be charming and the Windows software for converting audio and packing it into the ROM still works!
The (somewhat tedious) process goes like this:
1. Convert audio files to PCM (WAV) with specific bitrate and sample rate
2. Use MPAWRITE.exe to convert PCM to "MPA" format (mystery compression), one file at a time.
3. Use MPAWRITE.exe to insert a playlist of MPA format tracks into the music player ROM.
I'm a web dev and I want to build a web app that automates this whole process, so you upload a list of songs and it spits out a MusicPlayer Advance ROM with your music included.
I already successfully spec'd the format used for packing MPA into the ROM, but I haven't figured out what compression is used to convert PCM to the MPA format. I figured folks familiar with early GBA homebrew toolchains might be able to provide insights. Were there common types of file compression, or common audio file types, used for homebrew games at the time?
I have attached a folder with all the MusicPlayer Advance files, plus a text file where I describe the spec of the MPA audio storage in the GBA ROM, and also a before/after sample of PCM converted to MPA.
