Tablature - audio synchronization

[remi64000]

There is a synchronization problem between the speed of the audio and the tablature. the tempo is well indicated, here 177.
However, the cursor is good at the beginning but gets out of sync after a while.
The tempo varies a little, like on many "old" recordings, I put the solos at 185 to fill in but in vain.
However, it seems OK with the sync on a YouTube video.

I put a tablature in public for example:
https://tabs.parnaut.fr/tab/34

thank you again,

Rémi.

[t-berst]

tried the audio sync feature and it did not work at all.
maybe related to the comments in Tab.vue

            // Bug? If change to EnabledExternalMedia, and this.api.updateSettings(), this sync point can not be applied correctly.
            // So it must change to EnabledSynthesizer first, then change to EnabledExternalMedia
            this.api.settings.player.playerMode = alphaTab.PlayerMode.EnabledSynthesizer;
            this.api.updateSettings();
....

            this.api.settings.player.playerMode = alphaTab.PlayerMode.EnabledExternalMedia;
            this.api.updateSettings();

it seems that the call to updateSettings() messes up the sync config. I'm working on a fix and sumbit the PR later.

[louislam]

@t-berst

I don't think so, because most of my tabs are using audio files, don't have such issue.

I can't pin point the issue yet, but it could be the tab engine bug, because it went out of sync in the middle. (always same)

[t-berst]

@louislam, here are my repro steps :

• in the 'Hare no Hi ni' tab, 'Edit' then 'Youtube & Audio files'
• switch to Advanced Sync
• the sync points =>

\sync 0 0 0 
\sync 28 0 70000
\sync 93 0 272000

• switch back to the tab, play bar 28
  => the youtube video says 1'21.

if i understand correctly, we should be at 1'10 in the video.

I made a version that work, but i had to frantically re-apply the syncpoints everytime an updateSettings() is involved. I'll share the code in a PR.

[louislam]

Advanced Sync should be another issue?

Because op is not using Advanced Sync.

{"ok":true,"showOpenButtons":false,"tab":{"id":"34","title":"Hound Dog","artist":"Elvis Presley","filename":"tab.gp","originalFilename":"Hound Dog.gp","createdAt":"2026-03-28T16:58:43.591Z","public":true,"fav":false},"youtubeList":[{"videoID":"a63U9k2O4yM","syncMethod":"simple","simpleSync":0,"advancedSync":""}],"audioList":[{"filename":"Elvis Presley - Hound Dog [NO BASS].mp3","syncMethod":"simple","simpleSync":200,"advancedSync":""}],"filePath":""}

[louislam]

I think it is just the bpm issue, they are not perfectly 185. (Maybe 184.95 184.9, I don't know) I guess the song was from 1956, there was no equipment to follow the bpm perfectly like nowaday? I guess.

If you don't want to deal with the bpm, offset 0.35s is good enough to look like it is almost sync-ed. (Your current offset 0.2s is not enough to catch up)

[remi64000]

Yes, indeed, songs from the 50s or 60s often had variable BPM... and out of tune ^^.

[t-berst]

Advanced Sync should be another issue?

Because op is not using Advanced Sync.

you're right, my bad.
created #85