Synopsis
On the 31st of March, we had a brief discussion with spaceman_atlas in the osu!mania channel in the BN server after the introduction of the new sample rate audio rules. The point of the discussion was that some of the rules found in the Ranking Criteria — including this one — were added to comply with the game's parameters. In turn, this rose one question: couldn't some of these checks be done before the map is able to be ed? Most of these can be automated, as proven by Mapset Verifier and similar tools.

The Idea
This thread aims to be a place to discuss most — if not all — of the current Rules and Guidelines of the Ranking Criteria (or other game-breaking* restrictions outside of it) that could be repurposed as server-sided checks on the BSS pipeline, to avoid s from ing potentially "broken" sets to the platform.

It's important to emphasize this should only be for game-breaking issues. Maps can break the Ranking Criteria and still be playable. These checks should only be for things that, under no circumstances, should make it past the stage.

The Timing section is its own can of worms, as some maps do "break" the game for their gimmicks.

This will also need someone from the Dev team to be on-board. They will know better than we will what are the game's own limitations, and if something else should be added based on said limitations.

Once a list of issues is discussed by the community, and subsequently brought up for internal discussion, a GitHub issue formally and concisely describing the request will be made.

The (Current) List
Went through the current criteria, with some prospective checks to have based on some of the Rules & Guidelines known to have been placed to allow stuff not to break. This will be updated as stuff gets discussed in the thread to keep track of things! Do please discuss if any check should/shouldn't be here.

🛑 = Block .
⚠️ = Warning.

Last updated: 26-04-2025


A list with currently implemented checks can be seen here.

The Goals
By having a somewhat comprehensive list of checks, this should not only allow for new mappers to get used to the Do's and Dont's in a friendlier manner, rather than potentially bricking their s. Moreover, this should alleviate some of the burden that comes with checking these issues. As easy as it is checking MV before nominating the map, God knows how many times have these issues made it through Qualified.

While there should, ideally, be an extra layer of RC specific checks done before even being allowed to Nominate a set, that's somewhat outside the scope of this proposal which is geared towards multi-purpose checks done at an level, rather than at a nomination one.

very good

can we add stacked notes for mania?

audio:

Sample rate - yes, you won't come by these files just by accident
Encoders - yes
Bitrate - hard no. Reason - huge portion of the mappers, especially newer, which are the target audience of lazer editor, may not be familiar with all these rules, and chances they use something higher than 192 are quite large. Dealing with re-encoding the audio, changing offset, dealing with unsnaps is a bit too much for the newer mappers (and not only newer) and they should be spared from doing all this. Unless lazer acquires built-in audio converter which could magically just replace audio without the need to do any of that

bg & video:

min max res - min no, max yes. Reason - people still sometimes use 1x1px bg just for it to stretch to the screen size and fill it with monochrome color
video encoding - yes
video with audio - yes

metadata - yes

I guess so, though I'd say it's important to highlight that the game disposes of a couple guides (this and that) precisely to help out new mappers. Wouldn't throw it out of the window just for that alone, as we can always offset it with documentation on the issues and how to solve them.

Worth stating Bitrate is not a game breaking issue. If this were to be implemented, it would make more sense not at an level, but at a nomination one.

with the current list of audio/video rc proposed, i think one of the main hurdles would be that some mappers don't know how to adjust them to be rankable, so along with blocking them from (or imo making a BIG warning sign before they can click might be a good alternative), maybe link some guides on how to re-encode a video, or adjust audio bitrate/sample rate

KnightC0re wrote: 6cf6r

with the current list of audio/video rc proposed, i think one of the main hurdles would be that some mappers don't know how to adjust them to be rankable, so along with blocking them from (or imo making a BIG warning sign before they can click might be a good alternative), maybe link some guides on how to re-encode a video, or adjust audio bitrate/sample rate

Agree with this. I think technical hard constraints might frustrate (new) mappers and prevent them ftom ing things, but pre- checks that might end up a BIG warning sign is a pretty good idea.

I like it

for too high audio bitrate just convert it to lower on server side and auto adjust offset + shift timing

Spaceman has stated that auto fixes are out of the table for the time being. In any case, we have the guides, and having Warning prompts seems to be the way to go.

Think that for non-game breaking stuff, warnings before would suffice. But for stuff prompt to cause unintended behaviour, best if it does not leave the editor.

do blank .wav files still completely break file s, if so, then that

also consider flagging wrong filenames for the audio in the .osu (i.e. .osu calls for audio.mp3 but the folder only has audio.ogg or something)

agree w all the suggestions, though going back to your comment on timing, i dont think it should be affected. more often than not game breaking timing is caused by people who know what theyre doing, not new mappers. it also restricts apsire style maps from making it onto the website, which i think is an art of its own, and should be allowed to be ed

Randomly thought of this - there should be automatic checks for songs in FA catalogue if the map has all required FA tags, and if the map was submitted to mpg then all of those as well

Those probably would fit more prior to a nomination, at least the FA one. Would never be able to be a blocker given the amount of false positives in regards to the FA tag.

Moreover, I wouldn't necessarily say MPG is a "must do". It is nifty and s omly get benefits from it. But it should be something to opt-in if and only if the wants to, rather than being pestered about it multiple times. Or at least that's how I see it.

Updated the original post. Split the checks in two categories for the proposal. One that would block s from ing the sets whatsoever (done for big nono's) and the other that would offer warnings on , but not be a blocker. These warnings could act as blockers when nominating maps, as well as any other automatic change.

Here's a list of current checks done by the BSS, courtesy of spaceman_atlas:

The final proposal has been moved to GitHub based on the above.