Poor performance (freezing, dropped frames) of NDI feeds from 1 source

The last few weeks we have been having issues with NDI feeds out of our presentation software ProPresenter, fed into MimoLive as NDI sources. The pre-recorded videos played back this past Sunday over these feeds were glitchy and kept freezing. A secondary NDI output from the same source was being fed to a BirdDog Mini for NDI decode to a projector, and did not show any freezing or glitchiness. Reviewing after our service, the source performance monitor was showing continuous dropped frames just from that one source. We also have 3 BirdDog P200 NDI PTZ cameras, and those were not dropping frames like the presentation source.

Yesterday, I created a blank MimoLive file, and added the 3 NDI feeds out from the presentation source to it (1 feed is for projection to our in-person audience, one is for incorporation into a livestream / overflow / lobby mix, produced in MimoLive and output as NDI and to BoxCast, and one is for a stage display showing lyrics prompts and notes, etc. for our musicians / singers / speakers). I then watched source monitor. Initially the playback was smooth with just a few dropped frames upon connection, but over time the dropped frame rate was ticking up. Previewing of these same NDI feeds within Newtek NDI Monitor and Sienna NDI Monitor show acceptable playback. Decode to our projector also showed acceptable playback. Presentation software developers omitted 1080p30, so currently had everything (Mimo show, cameras, presentation feed) set to 1080p29.97, but I also experimented with other lower resolutions / frame rates… none were free of dropped frames.

I am trying to diagnose… does dropped frames in the MimoLive source monitor point toward an issue with the source itself (send-side), or with MiniLive’s ability to process those sources (receive-side)?

Hardware involved is fairly robust… iMac Pro running the presentation software: Xeon processors, Vega, lots of RAM, etc. iMac running MimoLive: i9, Vega, lots of RAM. Ubiquti Unifi Gigabit switch, all NDI gear in VLAN, etc. Running latest stable release… 5.7. Have not tried beta 5.8.x versions.

Any thoughts, suggestions, feedback welcome. Need to try to resolve for this Sunday.

You can see the results of this past Sunday’s live-stream here (the pre-recorded content played back from our presentation software starts around 8:00 in):