SRT Middleware

SRT Middleware is a proxy and scene switcher for SRT and OBS.

What it's not:

• Using encrypted streams.

It

• switches to BRB if no signal,
• switches to LBR if bitrate is below 300kbps
• switches to Live otherwise.
• can optionally listen to Twitch chat via Twitch EventSub WebSockets and switch scenes on authorized !commands.

Starting and stopping the stream is done with other tools (OBS Blade etc.)

Installing

go install github.com/dlukt/srtmiddleware@latest
mv ~/go/bin/srtmiddleware /usr/local/bin/

or

git clone https://github.com/dlukt/srtmiddleware.git
cd srtmiddleware
go build
mv srtmiddleware /usr/local/bin/

or

Download pre-built binaries for your OS/arch from the GitHub releases page

Running

The proxy MUST be running before starting the monitor.

Monitor config

monitor now supports a YAML config file. The default path is ~/.srtmiddleware.yaml.

Example:

monitor:
  grpc_addr: 127.0.0.1:50051
  obs:
    ws_addr: localhost:4455
    ws_pass: ""
  auto_scenes:
    live: Live
    lbr: LBR
    brb: BRB
  twitch:
    enabled: true
    client_id: your-client-id
    client_secret: your-client-secret
    redirect_url: http://127.0.0.1:8099/callback
    listen_addr: 127.0.0.1:8099
    access_token: ""
    refresh_token: ""
    expires_at: ""
    scene_commands:
      "!live": Live
      "!lbr": LBR
      "!brb": BRB
      "!intro": Starting Soon

systemd

• copy the service files from the contrib directory
• adjust the command line arguments

Proxy Arguments

--from="" and --to="" must be a SRT URL.

Examples

srtmiddleware --from="srt://0.0.0.0:12345?mode=listener" --to="srt://0.0.0.0:23456?mode=listener"
srtmiddleware --from="srt://remote.ip.addr:12345?mode=caller" --to="srt://127.0.0.1:23456?mode=listener"
srtmiddleware --from="srt://0.0.0.0:12345?mode=listener" --to="srt://127.0.0.1:10080?mode=caller"

You can also set a passphrase parameter if you're using listener mode.

srtmiddleware --from="srt://0.0.0.0:5555?mode=listener&passphrase=my_secret" --to="srt://127.0.0.1:10080"

See also further SRT options Or the Haivision document

--grpcaddr="" default localhost:50051 is the address the proxy provides stats at.

Monitor Arguments

--config="" defaults to ~/.srtmiddleware.yaml and is the primary monitor configuration file.

--grpcaddr="" default 127.0.0.1:50051 is the address the monitor connects to for getting the stats from the proxy.

--wsaddr="" default localhost:4455 is the OBS websocket instance the monitor connects to, to manage scenes.

--wspass="" is the password to use to connect to obs websocket. Read how to secure obs websocket. It's advised to either use a VPN is connecting from the outside or put it behind nginx for TLS termination, for privacy and security reasons.

--sceneLive="Live" --sceneLBR="LBR" --sceneBRB="BRB" are the scene names in OBS, they are case sensitive.

The monitor flags still work and override values from the config file.

Twitch Chat Control

This uses Twitch chat APIs and EventSub WebSockets, not IRC.

1. Create a Twitch application with a redirect URL that matches your local callback, for example http://127.0.0.1:8099/callback.
2. Fill in monitor.twitch.client_id, monitor.twitch.client_secret, monitor.twitch.redirect_url, monitor.twitch.listen_addr, and monitor.twitch.scene_commands in the config file.
3. Run srtmiddleware monitor login --config ~/.srtmiddleware.yaml.
4. Complete the browser login as the broadcaster account.
5. Start the monitor with srtmiddleware monitor --config ~/.srtmiddleware.yaml.

Authorized Twitch users:

• the broadcaster
• moderators in that channel

Behavior:

• a configured !command switches to the mapped OBS scene and enables manual mode
• while manual mode is active, bitrate-based switching is paused
• !auto resumes bitrate-based switching
• the monitor replies in chat after successful or failed actions

Relevant flags:

• --twitch-enabled
• --twitch-client-id
• --twitch-client-secret
• --twitch-redirect-url
• --twitch-listen-addr
• --scene-command !intro=Starting Soon

Thank you

To datarhei, who wrote this fantastic go native SRT package. To Marlow on Discord for the 300kbps Information.