Question Is there any way to hack Pokemon Sword/Shield music properly?

His method is correct. However, this does not allow for seamless songs. The songs will retain the original loop data. This is why we must search for the loop data and fix it.

 

As far as I know, the codec which this Wwise engine uses is Opus. With Sound Editor 2018, the song is seemingly encoded with said codec, allowing it to play in-game. However, I could be wrong.

 

Not as far as I know. Only songs with the same length in each part would sound seamless.

 

Yeah. With the stock loop and length data still in the game, any song that has a shorter length than the song you replace will still play at said length (meaning there will be inaudible silence until the length is met), and any song that is longer will be cut off at that point. However, if you manage to cut the song so it loops just like the other song, it should give the same loop effect.

 

yeah I replaced normal pkmn theme with smt nocturne one but it cuts off the song then loops.

 

Just from observations I did with PlatinumMaster, the sound system seems to be cobbled together nonsense, as some of the important data you would expect seemingly isn't there (such as loop data, track length, etc.) despite other games using the same system and not having any of these hurdles. It's not the first time Game Freak has programmed something that is more convoluted than it needs to be. I'm expecting, but certainly not hoping, that properly hacking the game's music will require rebuilding the sound system from the ground up.

 

Aren't songs like the Gym leader theme a bunch of songs that play at different times?

 

It is part of the BGM, if you are referring to the Gym Battle BGM.

 

I believe the dynamic music tracks are separate audio files linked together by a routine. That'd probably be even more of a headache to hack than just normal music.