Reverse engineer Makecode arcade song hex buffers

[maxitolplayer]

So I told ChatGPT to generate a Makecode song hex buffer. It didn’t work, so I asked one more time and it generated two (almost) correct tunes that worked. It worked so good that I asked ChatGPT again to make Python code and it worked but the actual song didn’t and it just sucked. I know you’re just going to ask me to use @UnsignedArduino’s Midi song converter for Makecode. But it sounds like crap and I’m not going to use something that only supports a midi file that is like one instrument. Anyone at microsoft or something should know how the Makecode song buffers work (because they’re the ones that coded it) so I want to know how to covert midi files or rttl ringtones to be converted to the Makecode song hex buffer. Thanks!

[richard]

@maxitolplayer the format is documented here:

pxtlib/music.ts

if you’re not used to working with binary encoded files then it can be a little tricky to wrap you’re head around. let me know if you have any questions!

[UnsignedArduino]

New Song format

I just remembered that I promised @UnsignedArduino that I would make a post linking to the new song format! Well, better late than never. The format of the song buffer is documented here: That file also contains all of the code for encoding/decoding the songs from buffers (in this case, uint8Arrays). The default instruments are all defined in the getEmptySong function. This code is mirrored in the arcade game engine here: If I were, hypothetically, making a webapp that converted midi file…

Might also help

@maxitolplayer

But it sounds like crap and I’m not going to use something that only supports a midi file that is like one instrument.

Do you have an example where it sounds very bad?

[maxitolplayer]

It’s due to lag and it sometimes has really high notes and sometimes lags out and plays a bunch of notes at the same time and i’m saying that it only supports a midi file with one track or channel and it lags due to excessive polyphony on different instruments.

[releca52]

Hello I saw this post but I still can’t figure out which parts of the hex mean what and how to generate a hex based off that. I saw the documentation in instrument.ts but I don’t fully know what it means. Is there some sort of in depth documentation or guide that I could use to attempt to reverse engineer this?

[richard]

@releca52 nope, that big comment is the only documentation on the format. if you let me know what you’re stuck on, i can try and point you in the right direction

also, the code for the actual encoding/decoding of songs is in that file i linked above. if the comment is confusing, that code might make it a little easier to understand (or you could always just take it to use for yourself)

[releca52]

Thanks thought that it was same as music.ts in explorer. Mb

[AlexK]

@maxitolplayer

I want to know how to covert … rttl ringtones to be converted to the Makecode song hex buffer

For RTTTL, you could use this.

RTTTL tunes extension

Ring Tone Transfer Language… is a popular format for tunes. With this library, you can play existing RTTL tunes in Arcade. RTTL https://en.wikipedia.org/wiki/Ring_Tone_Transfer_Language