H264 hardware artifacts

[alexdoshard]

Hello,

We’re observing strong artifacts on text with H.264 and hardware encoding.

It seems to be OS and hardware independent on the client side.

Config

• NoMachine server 6.9.2 – CentOS 7.6 = Physical Remote
• NoMachine client 6.9.2 – MacOS 10.14.3
• GPU Nvidia Quadro M4000
• Client settings: quality 100% and post processing image disabled

Observation

• See attached files

Questions

• Is this a common issue with h264 alongside hardware encoding?
• Have you got any tips on this specific issue ?

 

Thanks for your help

Attachments:

1. 

   nomachine-h264-artifact.png
   

2. 

   nomachine-h264-artifact2.png
   

[fra81]

Hi,

indeed we received several reports about artifacts with hardware encoding in the last few days and it looks like a problem in Nvidia drivers. Investigation is ongoing to find out if any tweak is possible to avoid to trigger this issue. In the meanwhile you can disable hardware encoding by adding this line to the ‘/usr/NX/etc/node.cfg’ file:

EnableHardwareEncoding 0

Please also tell us about your drivers version.

[alexdoshard]

Thanks a lot for the quick reply.

Our driver is 430.14.

Do you think it’s related to this post: Nondeterministic artifacts with T4 GPU H264 NVENC encoding https://forums.developer.nvidia.com/t/nondeterministic-artifacts-with-t4-gpu-h264-nvenc-encoding/82774

?

[alexdoshard]

To be sure, according to you is H264 more efficient than VP8 ?

 

Client or Server side

Are we agree this issue is coming from the server side ?

It looks like it dependent from the hardware client.

 

Fix

Would it be better to use quicksync instead in order to bypass Nvidia Driver ?

Have you got any leads on any tweaks, could I help ?

 

Thanks

[fra81]

First of all, thanks for letting us know the version and for the links. More investigations are needed to clarify all aspects.

To be sure, according to you is H264 more efficient than VP8 ?

Yes, H.264 will be more efficient regardless hardware or software encoding is used.

Are we agree this issue is coming from the server side ?

For sure it depends on the hardware encoder being enabled on the server side (it can’t be reproduced with software encoding), but we suspect that also the specific decoder in use could help to trigger the issue. If you have the possibility to test from a Windows client, we would like to send you further instructions. Would you help with that?

[alexdoshard]

Sure! Ready for instructions.

[alexdoshard]

Could I do also the proc from Mac or Linux ? I’ve got currently a Mac OS client.

[fra81]

There are no steps for Mac and Linux at the moment, but I will update you soon 😉

[alexdoshard]

I adapted the instructions described in the post “Screen artifacts/black flickering” for Mac and Linux.

It seems working like a charm ! Good job.

Tests

I’ve tested so far with the following configurations:

Client: Windows 10 GTX 1080 – Server Centos Nvidia Quadro M4000
Client Linux Nvidia Quadro 4000 – Server Centos Nvidia Quadro M4000
Client MacOS Intel Iris – Server Centos Nvidia Quadro M4000

Patch release

Do you know when a patch version would be available ? Would you have an ETA ?

One question on the side: is H265 planned to be integrated ? Is it possible to use as it is with NoMachine?

[fra81]

Hi,

glad to hear 🙂

The patch will be in one of the next releases, not sure if in the next one already. Anyway you can track the issue here:

https://www.nomachine.com/TR04R09608

As for H.265, it is in our plans and you can track it in the following Feature Requests:

https://www.nomachine.com/FR06O03428
https://www.nomachine.com/FR06O03429

 

[Author]

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