fra81

[fra81]

Hi,

colors generally need to be sub-sampled before they are fed to video encoders (typically from RGB to YUV format). This is particularly visible with bright colors (especially red) on dark backgrounds. For this reason, NoMachine performs an additional encoding pass to “fix” the colors (see https://knowledgebase.nomachine.com/FR03M02907). This is done progressively to not saturate the available bandwidth.

To alleviate this effect you can set the Display quality to the maximum level in the session menu panel, so that color refinement will happen faster. To make it even faster, you can check the ‘Disable multi-pass display encoding’ option in the advanced display options.

[fra81]

The screen blanking implementation is indeed about gamma settings. NoMachine encodes a copy of the framebuffer, so changing the framebuffer pixels would also affect what you see remotely.

As a possible alternative, you could turn the physical display off when you want to connect remotely, as explained at point 3 of this article: https://knowledgebase.nomachine.com/AR03P00973. At that point NoMachine will create a virtual (off-screen) framebuffer.

[fra81]

Please send the logs as explained above. Can you show us the ffmpeg command that you used for encoding?

[fra81]

Please check this article. If it doesn’t help, please gather server side logs as explained here. You can send them to forum[at]nomachine[dot]com.

[fra81]

Hi,

does this issue occur only when using fullscreen mode? And does it occur only when the remote screen is scaled (i.e. does it occur also in ‘viewport’ mode)?

Then please try to add the following key in the /Applications/NoMachine.app/Contents/Frameworks/etc/node.cfg file on the server machine:

DisplayServerExtraOptions "-oldeventapi 1"

Restart NoMachine and see if anything changes.

[fra81]

Hi Nyquist,

we can’t reproduce this issue in our labs and we didn’t receive similar reports. Should it happen again, please let us know, possibly with the steps to reproduce.

[fra81]

Hi,

sorry for the delay! We verified that indeed it doesn’t work and this issue is the reason:

https://github.com/raspberrypi/firmware/issues/1274

[fra81]

Hi,

so this seems to be a problem with the specific combination of graphics card and drivers. Even if sending data to the GPU for rendering can be fast, in some exceptional cases pulling data back from the GPU for screen capture can be much slower. When you stop lightdm, NoMachine creates a virtual framebuffer which is independent from the actual graphics card and drivers. Unfortunately that issue can’t be solved in NoMachine, but you may check for a different version of video drivers. For example, you may try to install proprietary Nvidia drivers or, in case you did already, install the open source ones.

[fra81]

Hi mrl,

is the server a headless machine (no monitor attached to it)? In that case, you can try one of the suggestions here: https://knowledgebase.nomachine.com/AR03P00973.

[fra81]

@dark_sylinc

You don’t work for NoMachine, but it seems like you do! 😉

@hellcats

I’d try the suggestions dark_sylinc rightly provided, starting from toggling hardware acceleration. This can also be done from the Server settings GUI, Performance panel.

[fra81]

Hi,

this is strange indeed. Did you have the chance to verify if this behaviour only occurs when connecting from the Mac? Does using the integrated monitor instead of the external one change anything? And would you run a debug package to gather more information?

[fra81]

Hi Tea,

we reproduced this issue in our labs and opened the following Trouble Report:

https://knowledgebase.nomachine.com/TR04S10193

You can select to be notified when it is fixed. Thanks for reporting!

[fra81]

Hi,

we can’t reproduce this problem in our labs. Can you explain exactly what you see in the video when it doesn’t work? You can attach a screenshot, if you want.

When using WRD, do you connect to the same desktop where also NoMachine is connected (that is the physical display)?

Finally, please make another test. While keeping ‘Use acceleration for display processing’ disabled, edit the ‘C:\Program Files (x86)\NoMachine\etc\node.cfg’ and add this line:

DisplayServerExtraOptions "-nodxgigrab"

Restart the NoMachine server and try again.

[fra81]

Hi,

surely the most recent sessions are the relevent ones. You can send only those or all logs, as you prefer.

[fra81]

Hi Remo,

I don’t see anything abnormal here. Tto reduce the GPU usage, you can try to check the ‘Disable client-side image post-processing’ and ‘Disable multi-pass display encoding’ options in the Display setttings in the session menu panel, but this is not necessarily what you want. To stop the NoMachine player from using the GPU completely, you would need to check instead the ‘Disable client side hardware decoding’ option. At this point the software fallback will be used, though fully optimized.

[Author]

Posts