VSE prefetch not showing clip's keyframe changes #82861

New Issue

Eric Jiang · 2020-11-20T01:43:25+01:00

Eric Jiang commented

2020-11-20 01:43:25 +01:00

System Information
Operating system: Ubuntu Linux 18.04.5 amd64
Graphics card: Nvidia GTX 1070

Blender Version
Broken: blender-2.90.1, blender-2.92.0-9d6d5b9bebd1-linux64
Worked: unknown

When VSE "Prefetch Frames" is turned on and you edit a clip's keyframes, the prefetch will continue rendering frames into the cache without your changes.

Launch Blender
Choose "Video Editing" under New File
Drag a still image (any PNG should do) into the timeline.
Drag clip extents so that it starts from frame 0 and goes to frame 2000.
In video preview, enable "Prefetch Frames"
Go to frame 20 in the timeline and select the clip.
Create an Opacity keyframe by clicking the dot next to Opacity.
Go to frame 80 in the timeline.
Change the clip Opacity to 0.4 and click the dot to create a new keyframe.
Start playback and see that the clip shows 100% opacity, even though the timeline shows that it should be 40%. Changing the proxy render size will clear the cache and show correct results.

If you clear the cache and do steps 8-10 quickly enough (i.e. before the prefetch finishes), you will also see that even though you modify the clip while prefetch is not done, the prefetching will continue to render incorrect frames. E.g. if you create the opacity keyframe while the prefetching is at frame 500, prefetched frames after 500 will still show as 100% opaque.

**System Information** Operating system: Ubuntu Linux 18.04.5 amd64 Graphics card: Nvidia GTX 1070 **Blender Version** Broken: blender-2.90.1, blender-2.92.0-9d6d5b9bebd1-linux64 Worked: unknown When VSE "Prefetch Frames" is turned on and you edit a clip's keyframes, the prefetch will continue rendering frames into the cache without your changes. 1. Launch Blender 2. Choose "Video Editing" under New File 3. Drag a still image (any PNG should do) into the timeline. 4. Drag clip extents so that it starts from frame 0 and goes to frame 2000. 5. In video preview, enable "Prefetch Frames" 6. Go to frame 20 in the timeline and select the clip. 7. Create an Opacity keyframe by clicking the dot next to Opacity. 8. Go to frame 80 in the timeline. 9. Change the clip Opacity to 0.4 and click the dot to create a new keyframe. 10. Start playback and see that the clip shows 100% opacity, even though the timeline shows that it should be 40%. Changing the proxy render size will clear the cache and show correct results. If you clear the cache and do steps 8-10 quickly enough (i.e. before the prefetch finishes), you will also see that even though you modify the clip while prefetch is not done, the prefetching will continue to render incorrect frames. E.g. if you create the opacity keyframe while the prefetching is at frame 500, prefetched frames after 500 will still show as 100% opaque.

Eric Jiang commented

2020-11-20 01:43:25 +01:00

Added subscriber: @erjiang-3

Philipp Oeser commented

2020-11-20 09:26:42 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2020-11-20 09:26:42 +01:00

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

Philipp Oeser commented

2020-11-20 09:26:42 +01:00

I can confirm there is something wrong with prefetching and animation.
#82776 (Sequencer: Driver on any strip property does not invalidate its cache [prefetch frames]) might be related.

So when following the steps I get the described behavior [prefetched frames not respecting the anim data].
However when the file is saved and reloaded, the cache gets recreated correctly.
Thus not sure if posting a file helps, but here it is:
#82861.blend

I can confirm there is something wrong with prefetching and animation. #82776 (Sequencer: Driver on any strip property does not invalidate its cache [prefetch frames]) might be related. So when following the steps I get the described behavior [prefetched frames not respecting the anim data]. However when the file is saved and reloaded, the cache gets recreated correctly. Thus not sure if posting a file helps, but here it is: [#82861.blend](https://archive.blender.org/developer/F9334174/T82861.blend)

Philipp Oeser removed the

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VSE prefetch not showing clip's keyframe changes #82861