Larix Broadcaster live translated subtitles
Larix Broadcaster offers custom streaming connections for phone broadcasts. Use a separate RTMP destination for StreamTranslate caption capture, or receive the normal feed in OBS and attach the StreamTranslate audio filter.
Open ControlChoose your IRL setupWhat you need
- Larix Broadcaster on iPhone or Android.
- An active account with streaming hours and your StreamTranslate IRL Mode URL.
- A second active destination for the caption feed, or an existing OBS receiver.
Use the account and URLs for the same environment. A staging caption feed does not appear in the released Twitch Extension unless the test channel is deliberately connected to staging.
Choose your caption output
Twitch Extension: each viewer chooses their language and appearance. Keep your Twitch account linked and the Extension active on your channel.
Browser Source: you choose the language, colors and appearance in Control. The captions are included in your video for everyone.
Do not activate two audio capture routes for the same voice. The Browser Source URL is for display; the RTMP URL or OBS plugin supplies audio.
Setup steps
- Create the caption connection
In Larix connection settings, add your full StreamTranslate RTMP URL. If the app separates server and key, keep /live/ in the server path and put the private key in the key field.
- Keep the normal broadcast destination
Enable the caption connection alongside Twitch or your normal receiver. Check the app’s active-connection limit and current plan options.
- Use compatible test encoding
Start the RTMP test with H.264 video and AAC audio. Avoid changing the working primary destination while checking the extra caption connection.
- Start and verify captions
Choose your spoken language in Control IRL Mode. Start Larix, check the caption connection status and confirm full sentences reach your caption output.
- Test the OBS alternative
If you use an OBS receiver, add our audio filter to the received Larix source instead. Keep only one caption capture route active to avoid duplicate audio.
Audio-only capture needs its own check
Larix documents audio-only capture and simultaneous connections. Before changing that setting, confirm whether it changes all active outputs; your Twitch video must remain enabled.
An audio-only output from a separate receiver can reduce the extra caption upload. A full audio/video RTMP destination still uses extra data even though StreamTranslate extracts only its audio.
For SRT or another transport, use an appropriate OBS or relay receiver. Our public caption URL is not a universal SRT, RIST or RTSP ingest address.
Frequently asked questions
Does Larix support more than one connection?
Larix documents simultaneous destination connections. Check the active-connection limit and the features available in your installed version.
Can I use Larix on either phone operating system?
Larix Broadcaster is available on iOS and Android. Check the actual destination settings on the device you use.
Do I need to leave the Control microphone running?
No. In IRL Mode, audio comes from your RTMP destination or the OBS audio plugin. Use Control to change settings; do not start a second browser microphone session.
Who chooses the subtitle language?
With the Twitch Extension, each viewer chooses their own language and appearance. With a Browser Source, you choose the language and appearance in Control and viewers see those captions in your video.
How should I adjust caption timing?
For Twitch Extension viewers, internal testing found 3–5 seconds is the sweet spot. Adjust to your actual video delay. This setting does not delay a Browser Source composited into your broadcast.
More IRL setup guides
OBS Studio, Streamlabs, Meld and other supported desktop software remain available through the desktop setup guide. For captions on the move, choose your phone or cloud workflow in the IRL Hub.