Hello!


In few words, I will describe my problem.

From time to time, in vMix, I have couple of black frames from my NDI cameras (PTZ OPTICS 12x). They don't have a pattern, they just appear and ruin my recording.


What I discovered since I have this problem and trying different stuff:


Camera web interface settings:

I have black frames when I use Encode Protocol H264.
I have grey frames when I use Encode Protocol H265.
I didn't test the MJPEG very much because of the big lag.

If I rise the bitrate to the maximum - 20480kbps, I have more often those black frames.
If I lower the bitrate to 12000kbps (NDI HIGH PROFILE), I still have those black frames, but less often.

Once, I didn't have any black frames at all on one camera, but I had on the other one. I checked the settings and I discovered that the "good" camera, had 4000kbps bitrate.


I have gigabit network, I don't think that a 40000kbps (from 2 cameras) bitrate should be a problem at all. The cameras are powered through the network cable from a TP LINK POE SWITCH with 5 ports.


I attached a photo with my network monitor. When the black frames appear, I can see a spike on the network like the one in the picture.

Maybe I can tune some settings from the camera menu to get rid of that black frames but I don't know the meaning of them. Maybe you can help me.
Fluctuate Level, Slice Split Enable, Split Mode, Slice size.


I do recordings more often then streaming, so I need the highest bit rate because it matters in my productions. If the cameras are working without black frames at 4000kbps...it's too low for me. I need every bit of quality than I can get.


Based on my informations, maybe someone can see a solution...


Thanks for your help.

I tried the following scenario:

I disconnected the second camera, so now I have only one camera connected and plugged into power source.
My bitrate is the default NDI High Profile, 12288 kbps.

I got rid of the black frames now. On my network monitor, I can see that spike from time to time but this time, on recorded footage, instead of black frames, I see a dropped frame. vMix doesn't report that frame as a dropped one, of course. So, now, that spike is translated in the footage as a dropped frame, not as some black frames.

I've done this test also without power adapter, only with POE power and it's the same thing. The power adapter doesn't change anything :(

I've tested this scenario also with 20000 kbps bitrate, and I got black frames, shorter than when I have also the second camera connected.

What could be the problem?

No, I didn't try that but I will. I don't have another POE switch but I will try with a non POE and I will power the cameras separately.

The funny thing is that in OBS I don't have any problems with black frames at all, no matter what bitrate I use...but vMix rocks in many situations and I don't want to stick with OBS.

First of all, I will try to connect the camera directly to PC. If the problem disappears, I will kill the switch :))

I will be back with an answer ASAP.

Thanks for your reply XAVER

I'm having this problem lately as well. I recently replaced a fixed PTZ Optics Zcam with a 30X NDI PTZ model to match the other two I have. I decided to update the firmware on all three cams so they were matching. Since this I have this problem. Video goes mostly black for a second or two. PTZ Optic support has indicated it may be a firmware problem, which I think it is. I'm going to downgrade the cams to the firmware my original two cams had.

Side note, the RTSP stream doesn't show this for me. Only the NDI. And my switch is a Ubiquiti UniFi Switch 8 60W. I have my cams and VMIX setup on a separate VLAN.

Well, the first firmware downgrade installed successfully but didn't solve the problem for me. I will request an older firmware and try again. My NDI Preset is set to Medium in the camera's web UI, with no changes to the individual settings. So my bitrate is 8192. Here's a video of what I'm seeing. Let me know if this isn't the same thing you're experiencing. I can start my own thread.

Untitled.mov (3,630kb) downloaded 16 time(s).

If it was a network error the rtsp stream would have been interrupted as well. I’ve had the rtsp stream up on one screen while vmix was up on the other on the same computer. It’s only happening via ndi in vmix for me.

PTZO told me today that Newtek supposedly fixed this is the most recent NDI Tools.

I searched for the new NDI tools and the newest version is 4.5 released in March, this year. Most probably I already have this version installed :(
My first thought was that they launched a new version these days.

Tomorrow I will try to update/reinstall NDI tools...maybe something good happens.

I spoke to PTZO today and they assured me the published Newtek NDI Tools had the fix. And this was coming straight from Andrew Cross. Do the existing Tools now should be the solution. Can you try? I am 10 days away from traveling back out to try to resolve.

Hello!

Almost great news. I updated the NDI TOOLS. The black frames are gone. Instead of black frames, now I've found some glitches. I will attach 2 images. I saw these glitches 2 times in a 30min recording.

I need to do more tests. Now, I've set both cameras at 20000kbps. Recording is at 3000kbps because I forgot to change the bitrate. I will test tomorrow more scenarios.

About the glitches, they are better then black frames. If we can get rid of them it would be perfect.