I found out what I had done wrong. I was previously using this command:
ffmpeg -f dshow -r 10000/1001 -i video="screen-capture-recorder" -vcodec libx264 -tune zerolatency -b 900k -f mpegts rtp://127.0.0.1:1234
Which I changed to this:
ffmpeg -f dshow -r 10000/1001 -i video="screen-capture-recorder" -vcodec libx264 -tune zerolatency -b 900k -f rtp rtp://127.0.0.1:1234
I just changed "mpegts" to "rtp" since that is the protocol I was using.