In a broadcast/live event environment, an NDI receiver/converter (for example NDI to HDMI or SDI) will use this flag/tag and produce a 60fps signal (or may not produce anything at all as 60p is not broadcast standard). Depending on your signal chain and hardware (switch, router,etc), this may not be supported. The behavior in live streaming software is similar, vMix and others, for example, will struggle with this 60fps flagged signal as it’s expecting 60fps but not receiving 60fps, this results in frame drops reported and stuttered playback.
Supporting 23.98, 24, 25, 50, 29.97 & 59.94fps correctly tagged/flagged NDI streams would make Arena & Avenue fully compatible with broadcast and live event hardware. And one of the most powerful playback solutions out there (NDI Audio would also be important).
Our use case would be Resolume Avenue or Arena playing out (3) 1920x1080 29.97fps NDI streams, that in turn would be picked up by three NDI to SDI converters going into a switcher driving three screens (or directly to projectors). If we’re also live streaming the event, we would use something like vMix to pickup the NDI streams and incorporate those into the live stream.
The only software we’ve found that does this correctly is PVP (ProVideoPlayer) from Renewed Vision.But much less powerful than Arena, and not updated as often. Then you have the uber expensive playout software for tv stations from softron.tv, where you’re paying $1k per screen or output.
UPDATE: Dynamically changing NDI frame rate isn’t desired, however setting NDI frame rate to the same value as the max composition frame rate (set by user) is highly advantageous. Then it’s up to the user/artist to manage their layers and/or hardware to get consistent/constant frame rate.