How to output from OBS to multicast/unicast:
Settings -> Output -> Output Mode -> Advanced
Recording -> Type -> Custom Output (FFmpeg)
FFmpeg Output Type -> Output to URL
File path or URL -> udp://224.0.0.1:1234?pkt_size=1316&buffer_size=65535 (working example, tweak it)
Alternatively you can directly send to just one PC in your system by using his IP, for example: udp://192.168.0.5:9999?pkt_size=1000
You can use any port that is free and accessible on the PC’s you want to use.
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Container Format -> Depends on the protocol, for udp it would be mpegts
Video Bitrate -> 2500 or higher (depends on your encoder)
Audio Bitrate -> 128 or higher (depends on your encoder)
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Activate the checkbox «Show all codecs»
Be aware, some combinations and codecs will not work for streaming! You will have to test to find your best combination.
Video Encoder -> libx264 / h264_nvenc (if you have an nvidia gpu) or other codecs can be used
Audio Encoder -> AAC, AC3 or even OPUS can be selected.
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Start a Recording, not a Stream.
You can now watch the stream in VLC (for example) on another PC in your local network. Open a network stream in VLC and enter the following address: udp://@224.0.0.1:1234(if you used this address as the «File Path» earlier, in the case of streaming to one pc you can enter udp://@:9999 on the receiving PC)
via https://obsproject.com/forum/resources/obs-studio-send-an-udp-stream-to-a-second-pc-using-obs.455/
ffmpeg UDP in/out syntax https://www.ffmpeg.org/ffmpeg-protocols.html#udp
more relay and ffmpeg examples https://obsproject.com/wiki/Streaming-With-SRT-Protocol
OBS scene scheduling/time-based switching https://obsproject.com/forum/threads/scene-change-and-stream-scheduler-based-on-date-time.95375/
If you need to send multicast to specific windows interface:
route add 224.10.20.30/32 inter.fa.ce.ip