Recording Multiple Cameras while Livestreaming?

[aega]

I've been tasked with doing a livestream, but also recording all the camera feeds separately so it's possible to make a post-production video that might not use the same camera angles as the livestream.

My setup:
2-3 HDMI Cameras into capture cards
3 Security Cameras using RTSP
3 Android Cell Phone Cameras using RTSP or MJPEG

I don't expect to be able to record video from the HDMI cameras directly onto the PC while livestreaming, so recording directly to SD Cards on the cameras is my best bet there.

I'm assuming I should just pull the other 6 cameras into some NVR software via RTSP to do the recording that way (so they're all synced) [any recommendations for software to do this?]. But I'm wondering if it's better to try to set up an RTMP server (recording everything) and pull feeds into OBS through that, or just go direct with OBS pulling the RTSP feeds individually? Right now I'm just pulling RTSP feeds directly from the cameras into OBS using gStreamer.

Thoughts? Recommendations?

 

[Geovarney]

For the recording I'd record as much as possible on the individual cameras and assemble it later in editing software

 

[atmosfar]

your problem will be dealing with exlusive access to video sources... ie being unable to have them open in multiple applications. To get around this I used FFMPEG and NDI forwarding, maybe using FfmpegGUI

example command --

start "FFMPEG: Camera 1" /min "C:\Program Files (x86)\FFmpegGUI\ffmpeg64.exe" -format_code Hp29 -f decklink -i "DeckLink Duo (1)" -f matroska -c:v h264_nvenc -b:v 30M -preset:v default -g 30 -pix_fmt yuv420p -c:a aac -b:a 128k -color_primaries bt709 -color_trc bt709 -colorspace bt709 -ss 2 -y %CAMERA_1_FILENAME%.mkv -f libndi_newtek -y Camera_1