3DS PDN

From GameBrew

3ds_pdn
3ds.png
General
Authorhax0kartik
Last Updated2021/06/14
TypeMedia players
Version2021
LicenseMixed
Links
Download
Website
Source

3ds_pdn is an open source implementation of PDN sysmodule which plays a MP3 from the sd card. Up until now, it was unknown whether this was possible, but as it turns out it is possible to do this. As anyone who has developed for 3DS before, should know that 3DS has two ways of playing audios, one through CSND and one through DSP. Apparently, it is possible to use CSND with modules to play music.

This is a functional POC of the music player (3DS PDN module rewrite) intended for developers and is able to play a MP3 off the sd card.

Building

To build you need to have ctrtool in your path, after which do make.

User guide

To use you need to put a MP3 file named as sound.mp3 on the root of your sd card and then enable game patching. The PDN sysmodule will spawn a thread in appcore for MP3 decoding and playing.

The POC works (atleast on N3DS, for O3DS you might need to change appcore to syscore or change the prio) but not smoothly, every time the system/game spawns a new thread there is a small break in audio due to the audio thread freezing and there are constant pop sounds. One possible reason is that the audio decoding and playing code will need soft-tuning.

Notes

  • Please remove patches for any other sysmodule before trying this as they can cause issues.
  • 3DS sleep mode will be broken by this, you'll need to restart your console.
  • On a N3DS, enabling Clock+L2C seems to make the code run a bit more smoother.
  • It might be better if we do not use PDN for our purposes, instead create a new sysmodule to be launched by the homebrew audio player app.

Credits

@luigoalma - Help improving the code.

External links