Tempo-related YouTube sync issues

A few issues with BPM (tempo / meter) changes as I edit my old analyses to incorporate HP2 features:

  • If a tab contains BPM changes, while playing the YouTube video the player cursor assumes the initial BPM and does not follow any changes.
  • Similarly, the “Set Tempo from YouTube Sync” action assumes the sync region contains no BPM changes, assigns the calculated constant BPM to the start of the tab, and adjusts the other tempo changes proportionately. This causes the tab to desync from the video.
  • All BPM calculations ignore the beat unit of the current meter; anything that uses a beat unit of 3 will report inaccurate BPM values.

Ideally Hookpad should support more than two keyframes so that keyframes can be associated with BPM changes, allowing “Set Tempo from YouTube Sync” to operate on multiple BPMs independently; but even then it would not be a good idea to automatically add a keyframe to every BPM change (e.g. when working with songs in 7/4 or highly additive meters), so there could still be BPM changes between two successive keyframes. Thus these issues need to be fixed if additional keyframes are indeed to be introduced in a future update.

Hey @HertzDevil, thank you for this post.

We will work on this one immediately!

Regarding everything else related to analyzing songs with BPM changes:

We talked about this a lot and built things with this in mind for some future update. As you know, we decided for the first launch of HP2 for analyses, we wouldn’t support it. As you mentioned, it requires an additional keyframe + sync point combo for each change and some extra logic during playback to figure out where the scrubber should be based on the youtube time. All very doable; but there was enough to worry about just getting the normal case to work, we didn’t want this uncommon feature to cloud things for launch.

Fixed in 2.11.9 released moments ago.