OBS and MediaMTX

1. Configure MediaMTX

Install MediaMTX using the official guide, create a configuration file, and replace its contents with the following. Make sure /recordings exists and MediaMTX can write to it.

logLevel: info
logDestinations: [stdout]

# This guide intentionally uses no authentication. Keep this server local.
authMethod: internal
authInternalUsers:
  - user: any
    pass:
    ips: []
    permissions:
      - action: publish
        path: bb/cam-multi
      - action: read
        path: bb/cam-multi
      - action: playback
        path: bb/cam-multi

api: false
playback: true
playbackAddress: :9996
rtsp: false
rtmp: false
srt: false
moq: false
hls: false
webrtc: true
webrtcAddress: :8889
webrtcLocalUDPAddress: :8189

pathDefaults:
  source: publisher
  overridePublisher: true
  record: true
  recordPath: /recordings/%path/%Y-%m-%d_%H-%M-%S-%f
  recordFormat: fmp4
  recordPartDuration: 1s
  recordSegmentDuration: 1h
  recordDeleteAfter: 0s

paths:
  "bb/cam-multi": {}

Start or restart MediaMTX with this file. It accepts OBS over WHIP on port 8889, serves the live WebRTC view on that port, and serves recorded playback on port 9996.

2. Configure OBS

Download OBS Studio if it is not already installed.

1. Add the source or sources you want to record. The capture area is up to you.
2. Set the OBS canvas and output to a 16:9 aspect ratio, such as 1920x1080. BBBB requires a 16:9 media source.
3. Open OBS streaming settings, choose the WHIP service, and use http://127.0.0.1:8889/bb/cam-multi/whip as the endpoint.
4. Leave authentication empty, start streaming, and confirm that OBS reports a live connection.

3. Enter BBBB settings

When BBBB and MediaMTX are on the same machine, use http://127.0.0.1:8889 for Live media address and http://127.0.0.1:9996 for Recorded media address. Leave both authorization fields empty. This configuration uses the path bb/cam-multi.

Keep clocks synchronized

BBBB uses the MediaMTX computer's clock to line up recordings with transcripts. Turn on automatic date and time synchronization for that computer.