App Profile: Larix Broadcaster: Live Stream

Larix Broadcaster is a professional streaming camera app for video and audio contribution using SRT, RTMP, Zixi, NDI, WebRTC, RTSP, and RIST protocols. It is built for mobile journalism, IRL streaming, remote production, and other live broadcasting workflows.

The app supports live streaming from iOS devices with high performance and flexibility. It offers H.264 and HEVC (H.265) video encoding, and AAC or Opus audio depending on protocol. It supports SRT in Caller, Listener, and Rendezvous modes (libsrt v1.5.3), with multipoint listener functionality. RTMP and RTSP are available with SSL (RTMPS/RTSPS). WebRTC is supported through WHIP signaling. Zixi integration provides AVC/HEVC support, SEI metadata, and Grove compatibility. NDI HX2 offers preview, Discovery Server support, and metadata setup. RIST streaming is supported in Push mode with Main and Simple profiles via librist v0.2.7.

You can configure multiple connection profiles and stream to several destinations simultaneously. The app includes a stand-by stream mode to launch in a paused state with different overlay settings. Pause is also supported to send muted sound and replace camera with alternate content.

Talkback is available via SRT, RTMP, Icecast, and SLDP, enabling audio return.

Larix supports UltraHD resolution and Dolby Vision HDR (via the HDR video menu). Both front and back cameras are supported, with live flipping, rotation between portrait and landscape, and hot switching. Multi-camera capture with picture-in-picture and side-by-side modes is available on iPhone XR, XS, and newer devices. It supports dual/triple camera setups including wide and telephoto lenses. Center Stage for iPads is also supported.

Camera controls include auto-exposure lock, white balance lock, manual color temperature, and pinch-to-zoom.


Adaptive bitrate streaming (ABR) is supported for SRT, with options for logarithmic descent, ladder ascent, and hybrid adjustment. Variable frame rate is also supported. ABR is disabled by default and can be enabled in the Video settings.

Bluetooth audio input and audio-only streaming are supported.

USB camera input is available on iPadOS 17 and later.

You can record streams as MP4 files, take screenshots, and save to iCloud. Recording customization allows higher resolution, alternate compatibility settings, and input gain control.

SEI metadata can be inserted into SRT, WebRTC, and RTMP streams for NTP sync using the Advanced menu.

Overlay features include GPS-based HTML overlays (requires Larix Premium), image, text, HTML layers, date/time overlays using Unicode LDML, and web widgets. You can assign specific overlays to live, paused, or stand-by states, and enable or disable layers while streaming.


Larix Grove enables easy sharing via deep links or QR codes. Visit https://softvelum.com/larix/grove/ for details.

Larix Broadcaster supports streaming to any media destinations including Nimble Streamer, Wowza, Red5, Flussonic, vMix, OBS Studio, and others. It works with major platforms like YouTube Live, Facebook Live, Twitch, Kick, Restream.io, Dacast, Cloudflare Stream, and more.

Larix Tuner cloud service support adds remote control, configuration backup, and session statistics. Visit the Larix Tuner website for more information.

Many features require a Larix Premium subscription. Premium removes the default overlay. It also unlocks multiple simultaneous outputs, Talkback, advanced overlays, ABR streaming, WHIP publishing, stream auto-start, USB/UVC camera support, and other. Learn more at https://softvelum.com/larix/premium/

Tutorials and documentation:
~ https://softvelum.com/larix/docs/
~ https://www.youtube.com/watch?v=Dhj0_QbtfTw
~ https://www.youtube.com/watch?v=4jOJm0XNxZc

Join our public beta testing at:
https://testflight.apple.com/join/mdxzNOxZ

Larix Broadcaster uses Apple’s Standard License Agreement:
https://www.apple.com/legal/internet-services/itunes/dev/stdeula/