Bug 394825

Summary:	Slow render on Khadas Vim2 Max and NanoPC T3+ Octa-core 64-bit ARM
Product:	[Applications] kdenlive	Reporter:	NicoD <dekerfnico>
Component:	Rendering & Export	Assignee:	Jean-Baptiste Mardelle <jb>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	fritzibaby
Priority:	NOR
Version First Reported In:	18.04.1
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description NicoD 2018-05-29 11:13:44 UTC

Hello.
For months I've been searching for a sollution on slow rendering with Kdenlive on 2 octa-core 64-bit ARM cpu's.
Specs:
Khadas Vim2 Max : Amlogic S912 Octa-core big/LITTLE 4 x 1Ghz + 4 x 1.5Ghz. 3GB ram
NanoPC T3+ : Samsung S5P6818 Octa-Core Cortex-A53 8 x 1.4Ghz

For my youtube channel I test all single board computers with the same project.
Some results Kdenlive 1080p 10minutes :
Khadas Vim2: 1h43m46s
NanoPC T3+ : 1h23m51s
Odroid C2 : 1h43m01s (4 cores at 1.75Ghz 64-bit)
Odroid XU4 : 1h12m43s (octa-core 4x1.4Ghz + 4x 2Ghz 32-bit)
Tinkerboard: 1h12m15s (4 cores at 1.8Ghz 32-bit)

As you can see, the Khadas Vim2 Max does it slower than the Odroid C2 wich only has 4 cores. And also all the 32-bit cpu's do a lot better than 64-bit ones.

Compared to my BMW Blender render in 1080p
1h10m27s NanoPC T3+
1h12m43s Odroid XU4
1h18m55s Khadas Vim2
2h00m38s Odroid C2
2h29m42s Tinker Board

The results here are the opposite. 64-bit cpu's do a lot better, and the octa core cpu's realy shine here.
In Blender all cores are always used to there max. In Kdenlive this is not so. Certainly at the end it takes 37 minutes to finish the last 10%

I have tried with lesser threads on the NanoPC T3+, and the result was very strange.
With 8 threads : 1h23m51s
With 6 threads : 1h24m29s
With 4 threads : 1h23m49s
With 2 threads : 1h41m64s
From 8 to 4 threads it all looks the same. It doesn't use the cores to the max, and certainly not when having to render transitions.
At 1 thread it only used 1 core at 100%

I have got a very long thread about this on the Khadas forum with many screenshots of the behaviour and a lot more information.
http://forum.khadas.com/t/underwhelming-performance-khadas-vim2-max-in-video-rendering-kdenlive/1466/71

I hope you can help me fixing this. I use single board computers to do video editing and rendering when traveling around Europe on my bicycle. I've always used the Odroid C2 for this, but only in 720p.
So I want a better performing SBC to be able to render in 1080p.
If you want anything tested are more information, please contact me.
My email adres is dekerfnico@hotmail.com
Thank you in advance. Greetings
NicoD
P.S.: My youtube channel where I test these sbc's.
https://www.youtube.com/channel/UCpv7NFr0-9AB5xoklh3Snhg

Comment 1 NicoD 2018-06-01 20:47:20 UTC

Some extra information. 
I tried to compile version 18.04 with the instructions here:
https://community.kde.org/Kdenlive/Development
I chose refactoring_timeline 
I'll try again with the other. 

For some strange reason I ended up with version 17.11.70.
There it performs even worse. 
Result with the NanoPC T3+ was 2h49m17s.

What I forgot to mention was that the places where it performs very badly are places with a dissolve and 2 x difference transitions. The places where there is no transition or effect it performs good.

I still hope you can help me solve this problem. 
I would expect these boards to do this in under an hour. That's why I bought them, I spend a lot of money on both. I don't want this to be in vain.
Thank you for your attention. I'll keep posting my progress here too. 
Greetings.
NicoD

Comment 2 NicoD 2018-06-02 00:12:55 UTC

I was able to install version 18.04.1
It is completely the same as with version 17.12.3
So between version 17.11.70 and 17.12.3 this has improved quite a bit.

But no difference in 17.12.3 and 18.04.1
The time was 1h24m10s
Again the last part, a difference transition of 1 minute long between 2 1080p video's. This takes more than 35minutes. Only 1 core is maxed, the others do almost nothing.

The rest of the project all the cores are at average at 70%. Sometimes it goes up, sometimes a bit down. But compared to the last bit it goes fast.
Greetings.

Comment 3 emohr 2018-12-14 19:12:41 UTC

Thank you for reporting. We marked this as a dublicate of 401186

*** This bug has been marked as a duplicate of bug 401186 ***