Poor picture quality after upgrading to NoMachine 8

[nxmac]

I frequently connect to my M1 Mac Mini from an x64 PC running Windows 10.  I recently upgraded both devices to NoMachine 8 and my picture quality has been bad ever since.  When I say bad, I mean I often can’t read the text or numbers in various applications.  Every now and then, the picture clears up to be as sharp as it can be, but more often that not, it practically looks more like a mosaic representation than it does like text and numbers.

The client and host are both connected to the Internet through synchronous fiber connections (client is 250 Mbps & host is 1 Gbps), so bandwidth shouldn’t be an issue.

Prior to updating, I had version 7.6.2_4 on the Windows client and the Mac host.  Since updating, I have been running 8.2.3_4 (x64) on the Windows client and 8.2.3_12 on the Mac host.  I don’t remember for sure, but it is possible that the v7 mac binary was for Intel while the v8 binary is for ARM, but even if that is true, I would expect such a change to lead to improvement vs detriment, and the picture was fine more often than not prior to the upgrade.  I have looked, but not found anything obvious in the settings that I could change in order to prioritize picture quality vs performance (that is to say I didn’t see any video quality settings and it isn’t obvious that I should manually choose any particular video encoding).  Picture/video quality searches tend to turn up results from 2014-2016 for me, so I haven’t had much luck searching.  Is there a document with configuration recommendations that might help here?

[Britgirl]

Hi, in version 8 support for hardware encoding on macOS was released (for both Intel and M1). Let’s check if it is related to that, so on the Mac server please disable HW encoding: server settings -> server performance -> uncheck “Use hardware encoding”.

[nxmac]

I tried to post a reply and got “Error: Are you sure you wanted to do that?” so I’m trying again…

When I disabled “Use hardware encoding” and reconnected after restarting the server via the GUI, I only got a blank white screen.  Additional restarts via terminal lead to the same behavior.  Re-checking the box and restarting the service through the GUI brought the display back.  I also tried unchecking “Use acceleration for display processing” since I wasn’t sure if it could also be new or different between versions.  With that unchecked, I still get a blank white screen while “Use hardware encoding” is unchecked, but may have a slightly better experience while “Use hardware encoding” is checked.  Specifically, the garbled picture may clear up slightly more often and/or to a better degree with that particular configuration, but I don’t think it is performing as well as it was pre-upgrade.

Is there any information I should provide to help diagnose the blank white screen with hardware acceleration disabled and/or is it possible that I need to take additional steps such as a full machine reboot for that setting change to work correctly?

[nxmac]

Are there any instructions available for downgrading?  I assume just re-installing the older version over the top of the newer version wouldn’t be a great idea, but I’m not sure if uninstalling and re-installing with a full configuration is necessary or if there are other options.  I believe the issue is with newer versions, but a proper downgrade could disprove that if I’m having ISP issues…

[Britgirl]

We are not aware of white screen issues when HW encoding is disabled on a NoMachine for Mac server, nor garbled screen. We would require:

1. logs of the server side when you encounter the blank screen issue. To extract logs of the affected server, please follow the instructions here: https://kb.nomachine.com/DT07S00244

2. screenshot or video of the garbled display issue

Please contact us via the website if you require a link to download an earlier version (footer of website -> contact us -> general enquiries).

[nxmac]

Because it is simpler, I have reproduced the white screen first, with logs from those instructions.  I will make a separate post for the garbled display issue.

Attachments:

1. NoMachine-log.tar.gz
2. nxdir.tar.gz
3. NoMachine-remote-log.tar.gz

[nxmac]

Now I am attaching the logs fort he garbled text.  The screenshot is included with the remote logs.  Based on the experiences I had while preparing to and trying to capture these logs, the “Use acceleration for display processing” checkbox likely has no effect (where the difference I thought I noticed before was likely just timing with network connectivity or something).  It often recovers from that garbled state very quickly and sometimes doesn’t recover from it at all until I switch windows.

Attachments:

1. NoMachine-log.tar-1.gz
2. nxdir.tar-1.gz

[Bilbotine]

Hi nxmac,

Unfortunately one of your attachments couldn’t be uploaded (error message: the file exceeds the allowed size).

Can you please send it by email to forum[at]nomachine[dot]com, making sure to reference the topic as the subject of the email?

Thank you in advance !

[nxmac]

That e-mail is sent.  Should I follow the log collection procedure to send logs for CapsLock won’t turn off as well?

[katpan]

Hi nxmac,

We received your email. The logs would be helpful.

Can you please send them by email to forum[at]nomachine[dot]com, making sure to reference the topic as the subject of the email?

Thank you!

[nxmac]

I’m confused.  Are you asking for logs for the other issue, or are you asking for the remaining logs for this issue?  If the latter, it looks to me like 5 files uploaded successfully here and only one didn’t, so I only e-mailed the 1 that didn’t…

[Britgirl]

nxmac, we got your email with the set of missing logs and will update this topic soon. Thanks for your patience 🙂

p.s we don’t need logs for the other topic, please check that topic to see a possible workaround that worked for us.

[fra81]

Hi nxmac, sorry for the delay. We identified 3 issues in your logs, not all dependent on NoMachine, that explain your observations. The first one is that the library used for software H.264 encoding is missing in your NoMachine installation, probably due to a problem occurred during the upgrade. We suggest to uninstall NoMachine completely on the Mac and reinstall it from scratch. The second issue is that the hardware H.264 encoder on the Mac lacks the capabilities needed for encoding by NoMachine. This doesn’t depend on NoMachine but it would be interesting to know the exact model of your Mac and the macOS version. These 2 issues prevented H.264 from being used at all and the VP8 encoder was used as a fallback, resulting in lower quality images. The third issue is a bug in the code responsible for falling back from H.264 encoding failures and it was causing the blanked screen issue. This will be fixed in the next NoMachine update.  

[nxmac]

The Mac is an M1 Mini running MacOS Monterrey (12.6.3).  Based on this unrelated github issue, it seems like my hardware and OS should support hardware H264.

The OS version was 12.6.1 when I started this thread and could feasibly have been 12.6.1 or 12.6.2 when the logs were collected.  Even with “Use hardware encoding” and “Use acceleration for display processing” checked the really bad video issues seemed to go away when I updated NoMachine to 8.4.2 (again, not sure what version I was running when I collected the logs), so I wonder if an upgrade could have replaced the missing library.  To be clear, when  say really bad, I mean text that was illegible (often worse than the screenshots I submitted, either permanently or for a countable number of seconds).

That having been said, certain things are still very poorly rendered, which may or may not imply the same issue persists on some level.  Specific examples include the login fields for this forum (like the background, form, and border colors are so close together, they don’t necessarily get rendered at all) and the reactions in the Messages app (Heart, ThumbUp, ThumbDown, HAHA, !!, ?) in dark mode are basically just blobs (I can see there are 6 distinct blobs, but I can’t identify which is which).

Given that the issue is actually much improved, would a complete re-install still be recommended, or should I just wait for the next update?  Separately, is it possible that new logs should be collected in case I’m now seeing a different issue?

[fra81]

The Mac is an M1 Mini

What model year?

it seems like my hardware and OS should support hardware H264

Yes, it does. The problem is that the hardware encoder doesn’t provide all the capabilities NoMachine relies upon.

That having been said, certain things are still very poorly rendered

Have you tried to increase the display quality in the Display settings panel of the session menu? You can also try to click on the ‘Disable client side post-processing’, in the advanced options.

would a complete re-install still be recommended

Yes, I would do that, just to be sure.

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