Audio Scrubbing bug #84543

System Information
Operating system: Windows 10 64-bit
Graphics card: RTX 2070 Super

Blender Version
Broken: (2.90, 2.91, 2.92 Alpha, 3.0)

Short description of error
Enabling "Audio Scrubbing" with "AV-sync, Frame Dropping, and No Sync" causes an issue with animations in the 3D Viewport and Timeline
Exact steps for others to reproduce the error
(AV-sync issue)

Open a default Blender file.
Create basic animation with any mesh, just something to show keyframe movement. Frames 1 - 250 should be enough for this procedure.
In the timeline window, click "Playback" and switch "Audio" to "AV-sync" and enable "Scrubbing". A sound file is not needed for this step.
Hit spacebar. The timeline cursor and animation should move as intended.
Hit spacebar again to stop the timeline cursor and animation.
Now the tricky part! Move the timeline cursor in any direction on the timeline, then instantly hit spacebar again. It may take a few tries but when it does work, the animation and the timeline cursor will not move. Yet, the "FPS counter" in the top left corner and the "Anim Player" icon will stay visible as if the animation is playing.
Press spacebar to stop the "ghost" animation.

(Frame Dropping and No Sync issue)

Using the same file from above, add a sound clip in the "Video Sequence" editor.
In the timeline window, click "Playback" and switch "Audio" to either "Frame Dropping" or "No Sync" and enable "Scrubbing". A sound file is needed for this step.
Hit spacebar. The timeline cursor, animation, and sound should play as intended.
Hit spacebar again to stop the timeline cursor and animation.
Same as before, move the timeline cursor in any direction on the timeline, then instantly hit spacebar again. It may take a few tries but when it does work, the animation and timeline cursor will move but the sound will not play.
Hit spacebar to stop the animation.

With both examples above, issues only popped up when "Scrubbing" was enabled. Disabling it did not produce the same results.

**System Information** Operating system: Windows 10 64-bit Graphics card: RTX 2070 Super **Blender Version** Broken: (2.90, 2.91, 2.92 Alpha, 3.0) **Short description of error** Enabling "Audio Scrubbing" with "AV-sync, Frame Dropping, and No Sync" causes an issue with animations in the 3D Viewport and Timeline **Exact steps for others to reproduce the error** (AV-sync issue) 1. Open a default Blender file. 2. Create basic animation with any mesh, just something to show keyframe movement. Frames 1 - 250 should be enough for this procedure. 3. In the timeline window, click "Playback" and switch "Audio" to "AV-sync" and enable "Scrubbing". A sound file is **not** needed for this step. 4. Hit spacebar. The timeline cursor and animation should move as intended. 5. Hit spacebar again to stop the timeline cursor and animation. 6. Now the tricky part! Move the timeline cursor in any direction on the timeline, then **instantly** hit spacebar again. It may take a few tries but when it does work, the animation and the timeline cursor will not move. Yet, the "FPS counter" in the top left corner and the "Anim Player" icon will stay visible as if the animation is playing. 7. Press spacebar to stop the "ghost" animation. (Frame Dropping and No Sync issue) 1. Using the same file from above, add a sound clip in the "Video Sequence" editor. 2. In the timeline window, click "Playback" and switch "Audio" to either "Frame Dropping" or "No Sync" and enable "Scrubbing". A sound file **is** needed for this step. 3. Hit spacebar. The timeline cursor, animation, and sound should play as intended. 4. Hit spacebar again to stop the timeline cursor and animation. 5. Same as before, move the timeline cursor in any direction on the timeline, then **instantly** hit spacebar again. It may take a few tries but when it does work, the animation and timeline cursor will move but the sound will not play. 6. Hit spacebar to stop the animation. With both examples above, issues only popped up when "Scrubbing" was enabled. Disabling it did not produce the same results.![Blender Scrubbing Bug.PNG](https://archive.blender.org/developer/F9556771/Blender_Scrubbing_Bug.PNG)

Added subscriber: @Kobazon

#101800 was marked as duplicate of this issue

Added subscriber: @mano-wii

Changed status from 'Needs Triage' to: 'Confirmed'

I'm not sure if the two bugs are really related, but I can confirm the first issue:

Added subscriber: @RaimonGuarroiNogues

Hi,

I can confirm this is also happening on Blender 2.93, and it makes VSE (almost) useless for any video work including sound.

System Information
Operating system: Linux-5.10.0-5-amd64-x86_64-with-glibc2.31 64 Bits
Graphics card: GeForce RTX 2080 SUPER/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 460.73.01

Blender Version
Broken: version: 2.93.0, branch: master, commit date: 2021-06-02 11:21, hash: 84da05a8b8

Thanks for your hard work and attention!
Raimon

Added subscriber: @dr.sybren

I cannot reproduce the issue, neither on the current 3.0 release branch (68e86c4816) nor on 2.93. I tried both cases (with & without sound), on Windows (2.93 only) and Linux (both 2.93 and the 3.0 release branch).

In #84543#1184394, @RaimonGuarroiNogues wrote:
I can confirm this is also happening on Blender 2.93, and it makes VSE (almost) useless for any video work including sound.

@RaimonGuarroiNogues The report describes two separate cases. Are you referring to the first or the second case?

@mano-wii could you do another test to see if you can reproduce, and which one of the two issues (or both?)

Changed status from 'Confirmed' to: 'Needs User Info'

I can no longer reproduce the first problem. But I was never able to replicate the second one so I'm not sure it was solved either.

@Kobazon, can you test with the latest daily build? https://builder.blender.org/download/

@RaimonGuarroiNogues The report describes two separate cases. Are you referring to the first or the second case?

I don't remember it exactly, but I guess I was referring to both cases. I will try to check with recent builds in 2.93 and 3.0 versions to see whether I can still reproduce the issue or not.
Thanks,
Raimon

I just saw the notification in my email. I downloaded 2.93.5 and 3.1 Alpha to see if it was fixed. The bug was still present in both versions; I was still able to replicate it. It hasn't been fixed yet.

Changed status from 'Needs User Info' to: 'Confirmed'

Added subscriber: @AldodeVos

As an extra note on the first bug:
The time you have to wait after moving the timeline cursor to prevent this from happening scales with the size of the scene.

This might or might not be expected from these kind of bugs, but I thought I'd add it just in case it seems more minor than it is in practice.

Added subscriber: @ChrisLend

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Audio Scrubbing bug #84543