NDI 2 NDI - no audio only video

vjmandala

New member
Hi, I tried running NDI and VMix from one PC to another also running either NDI and VMix, or from a Mac running OBS or NDI.

In all the above combinations when I send audio/video (combined source) only video is can be viewed at destination end (no VU meter action). If I select audio only the audio comes through fine.

Whether through WIFI or Ethernet or combo's of either.

If I use SRT works fine.

I am running ESET, have created (allowed) rules for all machines.

I am stumped.

Any pointers as to where this could be breaking down.

Cheers
 
To start, try using NDI Analysis to see if there is audio contained in the NDI stream. An audio entry only appears if audio has been encoded into the signal. Here is the entry you would be looking for in the Analysis header data. Beyond this entry, if there is audio, you will see Audio size, Audio recv and Audio send data.

1745417595104.png

Does audio work if you use a tool like NDI Test Patterns as the source?
 
G'day Kanep, thanks for that suggestion, I appreciate it, didnt know that tools existed. Handy as cheers!

Note, All PC's (HP z400 & AW m17r3) have 2.5GB and MAC 1GB network cards, PC's run at 1GB as I am using an TPLink AX6000 router w/ 1GBps LAN.

I also run ESET on both PCs, for good measure on PC-BB + PC-OBO I opend ports 5353, 5959-5969 based on these intructions.

Using SRT from aMAC to PC-BB and at same time SRT from PC-BB to PC-OBO all the AV at 4000kbps works perfectly fine.

Connecting either PC-BB or PC-OBO NDI Studio Monitor to aMAC OBS NDI out I either get AV working fine or audio drops out, mainly drops out connecting from PC-OBO.

Odd thing is, on PC-BB running VMix, I also run NDI Studio Monitor and connect to (itself) PC-BB VMix Output, audio comes in then drops out again. If I then connect PC-BB to MAC running OBS with NDI out I get AV no probs.

Even more strange, If on PC-OBO running VMix and NDI Studio Monitor I connect to PC-OBO NDI AV works fine.
Then on PC-BB NDI Studio Monitor I connect to PC-OBO NDI Studio Monitor (the output from OBO Studio Montor) the AV works fine.

Strangest of all. PC-BB NDI Studio Monitor connected to PC-OBO Vmix output (AV fine). The on PC-OBO NDI Studio Monitor connected to PC-BB NDI Studio Monitor AV works fine. But PC-OBO NDI Studio Monitor connecting to PC-BB Vmix output Audio drops out.

It seems as though this is a VMix (NDI) problem, rather than an NDI Tools problem!

I hope the above is not as confusing as it was to test and write here.


I ran command:
C:\Program Files\NDI\NDI 6 Analysis\x64>NDIAnalysis.exe /find
NDI Analysis v6.1.1.0
Copyright (C) 2023-2024 Vizrt NDI AB. All rights reserved.

NDI version : 6.1.1.0

Searching for NDI sources ... (5 found)
1: name="AMAC.LOCAL ( MUZZY_BROTHERS comp_STROBE)" aMAC
host="192.168.0.6"
port="5963"
type="NDI"
2: name="AMAC.LOCAL (aMAC - OBS)" aMAC *** Intermittent audio, video is ok.
host="192.168.0.6"
port="5962"
type="NDI"

3: name="AMAC.LOCAL (macOS AV Output)" MAC
host="192.168.0.6"
port="5961"
type="NDI"
4: name="BB-NDI (vMix - Output 1)" PC-BB
host="192.168.0.180"
port="5961"
type="NDI"

5: name="OBO-NDI (Studio Monitor 1)" PC-OBO ***This is NDI Studio monitor I am trying to view AV stream from***
host="192.168.0.140"
port="5961"
type="NDI"

Then ran:
C:\Program Files\NDI\NDI 6 Analysis\x64>NDIAnalysis.exe /source:"AMAC.LOCAL (aMAC - OBS)"
NDI Analysis v6.1.1.0
Copyright (C) 2023-2024 Vizrt NDI AB. All rights reserved.
NDI version : 6.1.1.0
22:58:20.856: Video receiver creation succeeded.
22:58:20.859: Video connection opened.
22:58:20.859: Audio receiver creation succeeded.
22:58:20.862: Audio connection opened.
22:58:20.874: Source is using NDI 5.5.3 on the APPLE platform.
22:58:20.892: Audio format changed. 44100Hz, codec=NewTek Mode 0, 2 channels.
22:58:20.892: Video format changed. 1920x1080, codec=SpeedHQ Mode 2, progressive, aspect ratio=1.78, frame-rate=30.00, no alpha channel.
22:58:21.505: Audio connection closed.
22:58:21.658: Audio connection opened.
22:58:21.775: Video connection closed.
22:58:21.928: Video connection opened.
22:58:21.935: Source is using NDI 5.5.3 on the APPLE platform.
22:58:22.849: Audio connection closed.
22:58:23.003: Audio connection opened.
22:58:23.020: Video connection closed.
22:58:23.173: Video connection opened.
22:58:23.188: Source is using NDI 5.5.3 on the APPLE platform.
*** If I switch to low-bandwidth mode I get audio coming through in VU meters ok, with some drop outs.

Then ran:
C:\Program Files\NDI\NDI 6 Analysis\x64>NDIAnalysis.exe /source:"BB-NDI (vMix - Output 1)"
NDI Analysis v6.1.1.0
Copyright (C) 2023-2024 Vizrt NDI AB. All rights reserved.
NDI version : 6.1.1.0
23:08:41.979: Video receiver creation succeeded.
23:08:41.982: Video connection opened.
23:08:41.983: Audio receiver creation succeeded.
23:08:41.987: Audio connection opened.
23:08:41.993: Source is using NDI 6.1.1.0 on the WIN64 platform.
23:08:41.995: Product, Long name=vMix 4K - 28.0.0.42 x64
23:08:41.996: Product, Short name=vMix
23:08:41.997: Product, Model=4K
23:08:41.999: Product, Manufacturer=vMix
23:08:42.000: Product, Version=28.0.0.42
23:08:42.015: Audio format changed. 44100Hz, codec=NewTek Mode 0, 2 channels.
23:08:42.017: Video format changed. 1920x1080, codec=SpeedHQ Mode 2, progressive, aspect ratio=1.78, frame-rate=30.00, no alpha channel.
23:08:42.387: Audio connection closed.
23:08:42.541: Audio connection opened.
23:08:46.990: Video data rate (Mbps). Avg=10.46
23:08:46.990: Video size (KB). Min=334.33 Avg=334.33 +/- 0.00 Max=334.33
23:08:46.997: Video recv (ms). Min=144.28 Avg=268.43 +/- 106.77 Max=525.34
23:08:46.999: Video send (ms). Min=29.93 Avg=222.49 +/- 155.58 Max=527.50
23:08:52.008: Video data rate (Mbps). Avg=11.19
23:08:52.008: Video size (KB). Min=334.33 Avg=334.33 +/- 0.00 Max=334.33
23:08:52.012: Video recv (ms). Min=181.02 Avg=248.91 +/- 51.22 Max=353.11
23:08:52.014: Video send (ms). Min=166.07 Avg=241.48 +/- 52.80 Max=366.03
23:08:57.025: Video data rate (Mbps). Avg=8.49
*** Whether I switch to low-bandwidth or not I get no audio in VU meters
 
Last edited:
In the first Analysis (AMAC.LOCAL (aMAC - OBS), there appears to be multiple messages of video and audio connections being closed and opened. It sounds like the NDI received is trying to open the data, nothing is received and it tries to restart the connection.
1747327189340.png

Looking at the second Analysis, I see that there is audio reported in the header, but there doesn't appear to be any audio appearing in what has been received. Only video is coming thru.
1747327270375.png

I'd make sure all firewalls and disabled, if you are using any 3rd party security software (on either side of the connection) disable it. For any Windows systems make sure the network type is set to Private (not Public). If none of that helps, try changing the NDI Access Manager receive types from Auto to Single-TCP and see if that makes any difference.
 
wondering if "Source is using NDI 5.5.3 on the APPLE platform." connected/playing with "Source is using NDI 6.1.1.0 on the WIN64 platform" could be a reason for this within your NDI workflow environment ?
 
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