VLC HEVC 12 bit performance issues on with AMD Ryzen CPUs (2-3FPS playback)

[Razor512]

Hi, After upgrading to a Ryzen 7 5800X, I noticed that for higher bit depth HEVC content, the performance is really bad with framerates in the 2-3 FPS (lots of frame skipping) range while audio plays normally.
I am still using my old GTX 970 as the last few GPU generations were ruined by miners and scalpers.

I am using VLC 3.0.12


The application will use 100% of 1 core worth of CPU time, while that core will run at 5GHz.
On Intel CPUs, even low end ones, the video plays fine using software rendering since in both cases, I have no hardware acceleration for the HEVC content.



The image shows the codec which causes the most trouble. On my Ryzen system, the CPU needs to run at 5GHz to maintain just 3FPS, while on my windows tablet running a core i5 4300Y, downclocks to 1.4GHz and uses 40% of 1 core, while running smoothly and no dropped frames for the same HEVC 12 bit content.

Wanted to also add that HEVC 10 bit runs with only about 5% of core

For the windows tablet, it is using the low end intel ULT-GT2 (HD 4200) which lacks acceleration for HEVC 12 bit content.

Has anyone else encountered this issue?

[Lotesdelere]

Please open Tools -> Messages (set Verbosity to 2) before you start the playback, and then paste the full resulting log here or on Pastebin.com if it's too long.

Also upload a short sample of your original problematic file to Zippyshare.com or to WeTransfer.com and then post the link to the file here.
https://www.zippyshare.com
https://wetransfer.com

If needed cut it with DGsplit and read here about how to do it:
https://forum.videolan.org/viewtopic.ph ... 35#p193335
100 MB max should be enough.


Then you should create a new ticket on the VLC Trac with your messages log, the link to your sample file and the link to this thread:
https://trac.videolan.org/vlc/

[Razor512]

I used DGsplit to create a smaller chunk of the video. Hopefully it is okay in that it keeps the same length and other metadata from the file, while extracting a smaller portion of the video, thus the actual end of the video content will not match with the end of the timeline.

Beyond that, the performance issue still remains with the resulting file.

https://www28.zippyshare.com/v/yZZLgiME/file.html


In collecting logs for 60 seconds, it shows the performance issue.
https://pastebin.com/x5UkpSv2

I also created a ticket.
https://trac.videolan.org/vlc/ticket/25502

[Razor512]

Just noticed something else the 4.0 branch plays it mostly smoothly with occasional stutters.

The latest nightly of of 3.0.12.1 also plays it much smoother but with occasional stutters. Previously it had more issues though I did a simple upgrade while keeping settings. A fresh install of the nightly without retaining any settings, has worked, though there is still the occasional dropped frame, though CPU usage is lower, with it using 1 core at 4.6GHz with that core being at around 60% usage. (still an overall higher usage than with my windows tablet running Windows 10 Pro and a core i5 4300Y). Before trying the nightly builds, I should have cleared all settings first, since I had a number changed while trying other troubleshooting steps.

Using the "Movies & TV" application that comes with windows 10, as well as the OEM HEVC codec from the microsoft store, results in completely smooth playback with 1 core at around 400-500MHz and around 20% usage on that core though the microsoft player has causes the video to have a green tint.

Overall, with the nightly builds being freshly installed, the video is now watchable, though CPU usage is still quite high.

The latest 3.0 nightly plays the video more smoothly than the latest 4.0 nightly.

[Lotesdelere]

I can't reproduce the issue with VLC 3.0.12 in software mode. Same goes with other HEVC 12-bit samples than yours.
Even on an 'old' i7-4790 I'm getting about 8% average of CPU usage.

Try another video output module:
http://wiki.videolan.org/WindowsFAQ-2.0 ... _output.3F

You can try with and without hardware acceleration.
You can also try to enable or disable some video options such as Overlay and/or Hardware YUV -> RGB conversions.

If it doesn't help then reset the preferences and try again:
https://wiki.videolan.org/VSG:ResetPrefs

[Razor512]

I tried some more testing with a fresh install of the non-nightly build.
The main issue for me is that on Intel, the CPU usage is low, but on Ryzen 5000, the CPU usage is extremely high. Basically on everything but Ryzen 5000, that format plays smoothly and with very low CPU usage.

In testing the different output modules with the non-nightly 3.0.12, it seems that the worst performing one is the Direct3D11 video output but only with this single format, everything else has it working perfectly smooth, with the CPU remaining largely idle power usage going from 25 watts to 29 watts. The best performing output module for the HEVC 12 bit so far is Direct3D9 Video output which manages to get pretty smooth playback but more stutters than than the 4.0 build.

Beyond that, the vlc-3.0.12.1-win64-14192fe3 seems to largely fix the playback issues (better playback than the 4.0 builds), though at a higher CPU usage relative to non Ryzen 5000 CPUs.

I managed to get a friend of mine to try it with his Ryzen build that uses a Ryzen 5, 3600, and it did not have this issue.

I feel I will have to do more testing, currently trying to find someone who has a similar hardware config, at least with a Ryzen 7 5800x, and the X570 chipset.

[Lotesdelere]

There might be an issue with some Ryzen CPUs then.
You should create a new ticket on the VLC Trac with your above report, the link to your screenshots and the link to this thread:
https://trac.videolan.org/vlc/