Changing offset (global or local) causes sudden 'timing snap' at the beginning of a map

percyqaz commented 5 years ago

To replicate:

Take a beatmap (most clearly visible on mania) where the first note begins very close to 0ms into the audio file
Change the game offset either locally or globally by about 100ms to make the effect visible
The hit objects will appear with no offset applied during the lead-in time before the audio
When the audio starts playing, the sync is applied causing mania notes to jump massively up/down (may affect osu!standard approach circles and such but I don't have any experience with this happening)

If you can't replicate this or need an example I can make a video clip illustrating this

The fix should just be to also apply the offset to the lead-in timer before audio starts playing (I experienced and patched this bug working on my own rhythm game project, and it was because I used a Timer to pad the time before the first note appeared to give at least 2 seconds of time after pressing "play". I'm assuming a similar strategy is used here, and the Timer is not having the offset applied correctly.)

Hopefully this summary makes it possible to track this down. I must stress that this bug is REALLY annoying on affected osu!mania maps as it makes it nearly impossible to time the first notes.

percyqaz commented 5 years ago

Update: here is a good example map https://osu.ppy.sh/beatmapsets/672291#mania/1421154

peppy commented 5 years ago

Can you confirm what your Universal Offset is set to?

percyqaz commented 5 years ago

Currently 0 but I have changed it to both positive and negative values to confirm it has the same effect as, and stacks with, local offset. I used to play with +20ms for a while and had this issue. On the chart provided I have -10ms set as my local offset which causes a minor but distracting bump at scroll speed 27

peppy commented 5 years ago

This is caused by the switch between virtual and audio-driver based time. It's already resolved in lazer via some more complex logic. I'll take a 5 minute look into this one, but I'm not sure it's an easily solvable one.

SupertCZ commented 5 years ago

This is a problem even on osu!standard, because it makes some maps hard to predict. For example this https://osu.ppy.sh/beatmapsets/746506#osu/1573321 with offset -15ms and the first note is hardly predictable.

cakiya commented 1 year ago

i too have this issue! it makes the first second of some maps really darn hard (especially DT/high AR maps)

annother example: https://osu.ppy.sh/beatmapsets/881764#osu/1844417 (snow halation reform's extra)

play the first second on DT (no hidden) without offset, then with -300ms offset. notice how it's kinda impossible to SS the first second of the map unless you retry 15 times or are good at jumpscare approach circles!!

realistically I don't think anyone is going to use -300ms offset but I use -180ms (no hitsounds; airpods pro) and it's still noticeable. peppy pls fix!

ppy / osu-stable-issues

Changing offset (global or local) causes sudden 'timing snap' at the beginning of a map #3