Video blinking and pixelated...not sure if there's a network problem

We met a blinking problem during our testing with CloudXR, after a long time running, maybe like 5 min ~ 10 min, video stream will randomly start blink, sometime is totally black, sometime is random color, after blinking for a couple of seconds it can goes back to normal, but then it blink again.
We also met an issue about video streaming, sometimes video becomes pixelated, but we found that maybe because the network traffic is not stable, could anyone also help to confirm this? This is just from my guess.


For the random blinking, are there specific titles do you see it in? Are you running CloudXR 2.0?

For the second part, you can check out section “5.3.4 Additional Logging Features” of the SDK Overview guide for instructions on how to enable the QoS logging feature, then use this to determine if there are hiccups in your network traffic.


Thanks for your reply, here’s my envrionment:
CloudXR2.0 for both client and server side
Oculus Quest 2 and Quest 1
windows running on VM, host uses Tesla V100 as graphic card.

I will open Qos log to see what happens.

Here’s a QoS log, you can see from 14:07:47, there a jitter and video rate drops

CloudXR Client QoS Log 2021-03-16 14.06.16.csv (369.2 KB)

We did another round of testing on this issue, seems as though the handshaking from the CloudXR to the quest attach to the TCP downlink speed and from there determine the pipe speed for the image streaming, during testing we fount that if TCP downlink speed is limited, video streaming will be pixelated and blinking, we don’t know if the relationship is exist but we can see from test results.

Please help me on this issue, thanks!!


I’m not sure I understand. Are you saying that:

Case 1

  1. Start streaming with no limitations on network speed
  2. Lower network speed
  3. Video becomes pixelated

Case 2

  1. Start streaming with lowered network speed
  2. Video is not pixelated

Basically if you lower network speed while streaming video becomes pixelated, but if start with that lowered speed the video is fine?


especially running in the cloud, try using ‘-f 50’ launch option. that should significantly reduce the bandwidth required, hopefully will increase quality, and as a side effect may stabilize part of the decode engine on android that is susceptible to significant network dropouts.

qos log certainly shows a number of points of sub-20mbps, and one or two drops sub-5mbps. Those are running bw averages, so it’s possible there was complete drops for a brief period. In a bit over 4 minutes, you also had 64 packets dropped, and show a very high jitter, which could all further contribute to lowered quality.

During testing right now we don’t think the blinking and pixelation problem is caused by bandwidth, but thanks for your reply.

-f 50 works!
Can I know what’s the default value of this parameter?
I guess that default value is not 50, so quest have very heavy workload on video decoding, then over heating or something, then blinking and pixelation appears.

Very apperciate for your help!

Take a look at section 3.3 in the 2.0 CloudXR Users Guide. This section describes the foveated scaling function

I’ve got it, thanks!