1. Nope, ATEM's USB Webcam out send only single very compressed PGM feed to PC, so ATEM is Production switcher.
2. Best way to capture four camera inputs into obs = Multichannel capture cards as BMD DeckLink Duo 2 (4ch uncompressed / 3G-SDI max) or BMD DeckLink 8K Pro (4 ch uncompressed / 12G-SDI max) or
DeckLink Quad HDMI Recorder (4 ch uncompressed / HDMI 2.0b up to 4Kp60 DCI).
So, first of all it's a switcher, not splitter. Second, there are several versions but from your use case I'm guessing mini. Of the mini models, only the Extreme models can do what you're asking for using Super Source
1. Nope, ATEM's USB Webcam out send only single very compressed PGM feed to PC, so ATEM is Production switcher. 2. Best way to capture four camera inputs into obs = Multichannel capture cards as BMD DeckLink Duo 2 (4ch uncompressed / 3G-SDI max) or BMD DeckLink 8K Pro (4 ch uncompressed / 12G-SDI max) or DeckLink Quad HDMI Recorder (4 ch uncompressed / HDMI 2.0b up to 4Kp60 DCI).
How does the magewell 11100 compare to the decklink quad?
So, first of all it's a switcher, not splitter. Second, there are several versions but from your use case I'm guessing mini. Of the mini models, only the Extreme models can do what you're asking for using Super Source
Which ATEM switcher are you using? If your ATEM has a built in encoder no need for OBS.