Page MenuHome
Create Task
Maniphest T65333

VSE: Playback speed regression
Closed, ResolvedPublic
Actions

Description

System Information
Operating system: Windows

Blender Version
Broken: 2.80, 451c533e25dde0c574a22fcbbd2624e09c804926

Short description of error
Default Video Editing startup file has slower video playback then old file created with Blender 2.79

fast.blend888 KBDownload

Exact steps for others to reproduce the error
It may be harder to reproduce on high-end machine, but in my case:

  • Factory startup
  • Open Video editing template
  • Add indexed video file
  • Set resolution / proxy size to match input
  • Set frame rate (59.94 was desired in my case)
  • Disable cache to rule out influence
  • Play

Got:

  • 26 FPS with alpha over blend
  • 39 FPS with cross blend (should be same as alpha over when opacity is 1, but that's another bug)

With fast.blend I got:

  • 47 FPS with alpha over blend
  • unstable, but 60 FPS with cross blend
    • 88 FPS maximum, when set scene FPS to 120

fast.blend file was probably created with Blender 2.79
I noticed this issue by coincidence. I will investigate cause of this, but reporting for testing, or if somebody wants to dive into this, I wouldn't mind.

@Brecht Van Lommel (brecht) if this is confirmed, should it be high prio?

Revisions and Commits

rB Blender
D4995rB2175fb021704 Fix T65333: VSE: Playback speed regression

Related Objects

Event Timeline

Richard Antalik (ISS) created this task.May 31 2019, 2:17 AM
Richard Antalik (ISS) edited projects, added Video Sequencer; removed BF Blender.
Brecht Van Lommel (brecht) added a project: BF Blender.May 31 2019, 2:22 AM
Brecht Van Lommel (brecht) added a comment.May 31 2019, 5:38 PM

Could be high priority, depends what the cause is.

Richard Antalik (ISS) claimed this task.Jun 2 2019, 10:42 PM
Richard Antalik (ISS) lowered the priority of this task from 90 to Normal.

Overhead is caused by image scaling in preprocessing stage. Linear interpolation is used, when render anti-aliasing is used in workbench settings, even if render engine is not set to workbench.

This also can affect quality of final render.

Richard Antalik (ISS) added a revision: D4995: Fix T65333: VSE: Playback speed regression.Jun 2 2019, 10:54 PM
Richard Antalik (ISS) changed the task status from Unknown Status to Resolved by committing rB2175fb021704: Fix T65333: VSE: Playback speed regression.Jun 7 2019, 1:25 AM
Richard Antalik (ISS) added a commit: rB2175fb021704: Fix T65333: VSE: Playback speed regression.