+### begin live streaming ###
+
+# comparing nginx rtmp to icecast
+# `mpv --cache=no` had about 2.5 sec latency vs 4 seconds.
+# Then I discovered this command which had about .5 sec latency:
+#ffplay -f live_flv -fast -x 1280 -y 720 -fflags nobuffer -flags low_delay -strict experimental -vf "setpts=N/60/TB" -af "asetpts=N/60/TB" -noframedrop -i rtmp://url_here
+## a lot of those args arent needed, here is what I ended up with:
+# #ffplay -f live_flv -fflags nobuffer -flags low_delay -i rtmp://localhost/live
+#
+# A problem with rtmp is that it doesn't support vp8/vp9, requiring the partly patent encumbered h264.
+# Looking at alternative protocols: dash & hls are both high latency, I tested dash with the nginx-rtmp
+# module and got about 5 seconds of latency, web results imply that is normal.
+#
+# Webrtc is what jitsi & bbb use, but an annoying thing is that
+# generally requires a web browser with javascript, or some special
+# client, and afaik, it has a smaller limit on number of clients.
+#
+# Another option is to try rtp/rtsp, there are some servers here:
+# https://en.wikipedia.org/wiki/Real-Time_Streaming_Protocol
+
+
+## reference for setting up rtmp
+# pi nginx libnginx-mod-rtmp
+# cat >/etc/nginx/modules-enabled/rtmp.conf <<'EOF'
+## based on https://opensource.com/article/19/1/basic-live-video-streaming-server#comments
+## and https://github.com/arut/nginx-rtmp-module/wiki/Directives
+
+# rtmp {
+# allow publish 127.0.0.1;
+# deny publish all;
+# server {
+# listen 1935;
+# application live {
+# live on;
+# record off;
+# }
+# }
+# }
+# EOF
+
+### end live streaming ###
+