exch-bms2
Proposal for an algorithm that allows "split difficulty" for BATTLE mode.
I have a theoretical solution to split difficulty in BMS.
Right now split difficulty battle in BMS is not possible because there is no way to tell the BMS player that two different BMS files belong to the same song. We also can not assume that two charts in the same song folder are for the same song. E.g. in "mnemogeny" (from BOFU2015) each difficulty is a different part of the song. (NORMAL sounds different to HYPER, and HYPER sounds different to ANOTHER).
This is why I have thought about a solution to this problem.
The BMS player needs to find out if two BMS files sound identical. This can be done by moving ALL playable notes to channel 01 (bgm) Do this on both BMS files. Then compare the two files to see if all the BGM events align. If all the BGM events are identical, then this means the two BMS files sound identical. That means split difficulty is possible, as both players will play the same music.
I hope this feature will be considered, as having split difficulty in a BMS player would be rather groundbreaking and attractive. (It also allows people to play BMS together with friends who aren't as skilled in the game.)
