kaukosohva

Play games remotely with Linux.

Current state

This is proof of concept prototype for technical users.

Architecture

Main problems TODO

• Lower the latency for streaming
  • Minimize streaming buffer(s)
  • Tune h264 parameters for lowest latency
  • Tune RTP parameters for lowest latency
  • Constant or variable bitrate (CBR or VBR)?

FAQ

• Why h264?
  • Because GPU encoding/decoding hardware acceleration
• Why h264 over RTP?
  • Because it's a standard - https://tools.ietf.org/html/rfc6184
• Why multicast?
  • Eliminates need for extra server software as kernel sends host's stream to everyone connected to the VPN automatically
• Why GStreamer?
  • Lots of tuning options
  • Lots of plugins
  • Debugger - https://gstreamer.freedesktop.org/documentation/tutorials/basic/debugging-tools.html
  • View latency issues in the pipeline - https://www.flathub.org/apps/details/org.freedesktop.GstDebugViewer
• Does it matter who hosts VPN (WireGuard)?
  • Who has the most bandwidth and stable connection is recommended

See

• host directory for how to host a game
• remote-player directory for how to connect to a host as a remote player

Research

• Network
  • https://en.wikipedia.org/wiki/Multicast_address
  • https://en.wikipedia.org/wiki/Reserved_IP_addresses
  • https://en.wikipedia.org/wiki/Private_network
• Video/Audio
  • https://en.wikipedia.org/wiki/Real-time_Transport_Protocol
  • https://en.wikipedia.org/wiki/Advanced_Video_Coding
• GStreamer
  • https://gstreamer.freedesktop.org/documentation/plugins_doc.html?gi-language=c
  • https://github.com/GStreamer/gstreamer
  • https://lists.freedesktop.org/archives/gstreamer-devel/
  • https://github.com/GStreamer/gst-rtsp-server

Not tested yet

If h264 over RTP multicast doesn't pan out there's still many things to try with GStreamer:

• Drop multicast and stream to UDP port in a remote player's machine (this limits player count)
• Try h264 inside MPEG-TS container over multicast
• Try GStreamer's RTSP server if the host doesn't have enough upload bandwidth for all players there's RTSP proxies like rtsp-simple-server
• RTMP
• SRT
• and others

Tested, didn't work

• ffmpeg, mpv, vlc
  • too many buffers
  • 1000-4000 ms+ latency even locally