Scene Strip playback fps regression #70239

New Issue

tintwotin · 2019-09-25T13:09:10+02:00

tintwotin commented

2019-09-25 13:09:10 +02:00

System Information
Operating system: Windows-10-10.0.17763 64 Bits
Graphics card: Intel(R) UHD Graphics 600 Intel 4.5.0 - Build 24.20.100.6137

Blender Version
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: f6cb5f5449
Worked: (2.79)

In 2.79:
Duplicate the scene(with a camera inside).
Select the new scene.
Open the Video Editor workspace.
Add a scene strip from the first scene.
Set the Render Resolution to 100.
Save the file.

Do the same thing in 2.80.

Open both files in two different instances of Blender 2.80 and compare the playback speed, after setting both to Workspace > View Transform > Standard.

The file generated in 2.79 I get a playback rate of 16-20 fps.
SceneStrip_createdIn_279.blend

The file generated in 2.80 I get a playback rate of 9-11 fps.
SceneStrip_createdIn_280.blend

I tried to look through the settings to find any differences, but I couldn't find any, but there must be a difference in the settings causing this regression?

A gif of the playback rates:

**System Information** Operating system: Windows-10-10.0.17763 64 Bits Graphics card: Intel(R) UHD Graphics 600 Intel 4.5.0 - Build 24.20.100.6137 **Blender Version** Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: `f6cb5f5449` Worked: (2.79) In 2.79: Duplicate the scene(with a camera inside). Select the new scene. Open the Video Editor workspace. Add a scene strip from the first scene. Set the Render Resolution to 100. Save the file. Do the same thing in 2.80. Open both files in two different instances of Blender 2.80 and compare the playback speed, after setting both to Workspace > View Transform > Standard. The file generated in 2.79 I get a playback rate of 16-20 fps. [SceneStrip_createdIn_279.blend](https://archive.blender.org/developer/F7774440/SceneStrip_createdIn_279.blend) The file generated in 2.80 I get a playback rate of 9-11 fps. [SceneStrip_createdIn_280.blend](https://archive.blender.org/developer/F7774442/SceneStrip_createdIn_280.blend) I tried to look through the settings to find any differences, but I couldn't find any, but there must be a difference in the settings causing this regression? A gif of the playback rates: ![Scene_strip_regression.gif](https://archive.blender.org/developer/F7774453/Scene_strip_regression.gif)

tintwotin commented

2019-09-25 13:09:10 +02:00

Added subscriber: @tintwotin

Bastien Montagne commented

2019-09-25 13:54:12 +02:00

Added subscriber: @mont29

Bastien Montagne commented

2019-09-25 13:54:12 +02:00

There is one major difference between those two files - the 2.80 one uses nodes for its cube material, while the 2.79 does not. Please check whether removing that difference in one way or the other also fixes the fps differences.

Bastien Montagne commented

2019-09-25 13:54:35 +02:00

Also please Try the latest build from our buildbot.

Also please Try the latest build from [our buildbot](https://builder.blender.org/download).

tintwotin commented

2019-09-25 14:01:30 +02:00

It is actually like 2 fps faster with the node texture on(on a build I did this morning), so that doesn't explain the difference in playback rate.

Bastien Montagne commented

2019-09-25 14:15:23 +02:00

Then that’s likely a driver issue (here on linux, on an Haswell GPU, both files run above 24fps - in a debug build!). Please install the latest official drivers.

Then that’s likely a driver issue (here on linux, on an Haswell GPU, both files run above 24fps - in a **debug** build!). Please install the [latest official drivers](https://downloadcenter.intel.com/product/126787/Intel-UHD-Graphics-600).

tintwotin commented

2019-09-25 19:30:10 +02:00

Thanks for the suggestion, but updating the driver doesn't change anything here.

Maybe you'll see the difference if you set the render fps to something which will put a strain on your system like 100 fps or 4k video, and the see if both files are played back at the same fps. If they are then maybe this is a Windows related problem?

[Edit: Tried on another faster computer and playing the two files(and changing the fps to 60) resulted in 2.79 file was playing 37 fps and 2.80 file 30 fps]

Thanks for the suggestion, but updating the driver doesn't change anything here. Maybe you'll see the difference if you set the render fps to something which will put a strain on your system like 100 fps or 4k video, and the see if both files are played back at the same fps. If they are then maybe this is a Windows related problem? [Edit: Tried on another faster computer and playing the two files(and changing the fps to 60) resulted in 2.79 file was playing 37 fps and 2.80 file 30 fps]

Bastien Montagne commented

2019-10-14 12:02:20 +02:00

Added subscribers: @fclem, @Sergey, @Jeroen-Bakker

Bastien Montagne commented

2019-10-14 12:02:20 +02:00

Not sure whether that difference in speed is expected, maybe @Jeroen-Bakker or @fclem would know more? Or maybe @Sergey, although I would not expect depsgraph to be a bottleneck with such a simple scene…

Sergey Sharybin commented

2019-10-14 12:09:31 +02:00

@mont29, can you reproduce the issue? For me both files are around 75 to 100 fps (jumping between those values).

@tintwotin, if there are two files which has different fps in the same version of Blender there must be a setting which is different across those files. It is not just a color management which affects on this. Try figuring this out. Is easier for someone who can reproduce the issue.

@mont29, can you reproduce the issue? For me both files are around 75 to 100 fps (jumping between those values). @tintwotin, if there are two files which has different fps in the same version of Blender there must be a setting which is different across those files. It is not just a color management which affects on this. Try figuring this out. Is easier for someone who can reproduce the issue.

Bastien Montagne commented

2019-10-14 12:11:14 +02:00

@Sergey nope, for me as well speed are very high and similar.

tintwotin commented

2019-10-14 12:12:46 +02:00

Added subscriber: @LazyDodo

tintwotin commented

2019-10-14 12:12:46 +02:00

Some time ago did @LazyDodo profile the export of the default cube with ffmpeg and in that case it was color management(implemented in april?), which caused slower exports. Maybe scene strip playback is affected by this too, but some non-ui option is set differently between 2.79 and 2.80?

https://blender.chat/channel/vse?msg=k55ZbMCjSHMBavDtK

Some time ago did @LazyDodo profile the export of the default cube with ffmpeg and in that case it was color management(implemented in april?), which caused slower exports. Maybe scene strip playback is affected by this too, but some non-ui option is set differently between 2.79 and 2.80? ![image.png](https://archive.blender.org/developer/F7816106/image.png) https://blender.chat/channel/vse?msg=k55ZbMCjSHMBavDtK

tintwotin commented

2019-10-15 08:23:10 +02:00

In #70239#795372, @Sergey wrote:
@tintwotin, if there are two files which has different fps in the same version of Blender there must be a setting which is different across those files. It is not just a color management which affects on this. Try figuring this out. Is easier for someone who can reproduce the issue.

I have been comparing the UI settings of those two files, and didn't find any difference, but it feels like looking for a needle in a haystack. Are there any ways two .blend files can be compared, or could 2.80 changes to the file format give a clue?

> In #70239#795372, @Sergey wrote: > @tintwotin, if there are two files which has different fps in the same version of Blender there must be a setting which is different across those files. It is not just a color management which affects on this. Try figuring this out. Is easier for someone who can reproduce the issue. I have been comparing the UI settings of those two files, and didn't find any difference, but it feels like looking for a needle in a haystack. Are there any ways two .blend files can be compared, or could 2.80 changes to the file format give a clue?

Richard Antalik commented

2020-01-13 17:06:23 +01:00

Added subscriber: @iss

Richard Antalik commented

2020-01-13 17:06:23 +01:00

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

Richard Antalik commented

2020-01-13 17:06:23 +01:00

Can confirm regression(2.79 vs 2.83) with lots of subdivided cubes or empty scene with camera.

I looked into reason for this quite long time ago and it looks like reading memory from GPU is slow.
I didn't compare this to 2.79 code though, and I don't have good knowledge of openGL workings, so I don't exactly know root cause of regression and if it's easy to optimize the code.

Before I can dive into this and know more, I will treat this as a known issue.

Can confirm regression(2.79 vs 2.83) with lots of subdivided cubes or empty scene with camera. I looked into reason for this quite long time ago and it looks like reading memory from GPU is slow. I didn't compare this to 2.79 code though, and I don't have good knowledge of openGL workings, so I don't exactly know root cause of regression and if it's easy to optimize the code. Before I can dive into this and know more, I will treat this as a known issue.

tintwotin commented

2020-01-18 12:51:11 +01:00

For whatever it is worth, eevee rendered scene strips are playing painfully slow compared to the playback of eevee rendered in the 3d view(gif):

For whatever it is worth, eevee rendered scene strips are playing painfully slow compared to the playback of eevee rendered in the 3d view(gif): ![eevee_scene_strips.gif](https://archive.blender.org/developer/F8285140/eevee_scene_strips.gif)

tintwotin commented

2021-09-03 18:40:29 +02:00

Removed subscriber: @tintwotin

tintwotin commented

2021-10-26 08:57:54 +02:00

Changed status from 'Confirmed' to: 'Archived'

tintwotin closed this issue

2021-10-26 08:57:54 +02:00

tintwotin commented

2021-10-26 08:57:54 +02:00

As I do not have anymore time or motivation for a continued investment in the Blender project, I'm giving up on this report for now.

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Scene Strip playback fps regression #70239