Beats plays custom ATRAC songs when it should reject them

[NABN00B]

I apologize in advance for the long post, but please stick with me. 😅

As you know, lately I've started going through games that support custom background music to document the feature on the website.

During this process one of the oddities I found is that Beats (or Shouten Beat) not only looks for custom MP3, but also AT3 files. Not only that, but it also plays them (flawlessly) in PPSSPP. At first I happily acknowledged this as an undocumented feature.

When I was doing tests of other games on the PSP, I decided I might as well test Beats too. To my surprise, the game rejected to play the song. It displays the message "There is a problem with the selected track, the game cannot proceed. Please choose another track."

I immediately started doing more tests on PPSSPP, using AT3 songs extracted from various game dumps and 1 that I converted from MP3. All of them worked perfectly. Then I copied the very same files to my PSP, and just like last time, not a single one of them was accepted by the game.

At this point I realized I must have discovered a rabbit hole.

My first instinct was to test how it behaves with the "Use old Atrac implementation" option. The game still played the files. I've tried "Use FFMPEG for all compressed audio" too but that doesn't seem to be in play here. My second stop was testing it on v1.18.1 release... and the game finally rejected the ATRAC songs!

From here it was obvious that something changed during the new Atrac implementation that affects the game this way. I manually tracked it down to v1.18.1-1335-ga0cc07559e #20117. This is the first version where the game plays AT3 songs.

Now the question remains, what do we do knowing this?

On one hand, this a behavior that doesn't happen on the PSP, and we don't know if it was intended for the game to play AT3 music. On the other hand, it is an obvious improvement over the PSP, similar to how you mentioned the idea of resampling MP3 songs to 44.1 kHz. It is also useful to be able to play custom songs this way until #14812 is resolved.

Either way, I thought opening an issue was the best way to let you know about and document this phenomenon.
Feel free to close it with not-an-issue.

[hrydgard]

This is quite interesting, it was never the intention of #20117 to change any behavior! In this case it does seem to be beneficial or at least not a problem, but I guess it's possible that some weird other edge case could be badly affected.

That said, not that likely to be the case, so I'm not sure this is a high priority issue. Still, thank you, this is worth reporting and knowing about.