StreamLive Pro

Stream from Larix Broadcaster with RTMP or SRT

Stream from Larix Broadcaster on a phone to StreamLive Pro with RTMP or SRT: how to build the connection URL, which settings to pick, and when you need no app at all.

Updated November 5, 2026 · 4 min read

Larix Broadcaster is a phone encoder app from Softvelum. It can push your phone's camera to StreamLive Pro over RTMP, RTMPS or SRT, and StreamLive Pro sends that one stream on to every channel you ticked. In Larix you add a connection with one URL; for RTMP that URL is the address from the Encoder card with the stream key joined to its end.

Before you set it up, check whether you need an encoder app at all. If the phone is only an extra camera next to your computer, StreamLive Pro's own phone camera link works in the phone's browser with no app (Use your phone as an extra camera), and going live from the phone itself is covered in Go live from your phone. Larix makes sense when you want its manual controls, its SRT support, or a phone that streams on its own away from any computer.

Before you start

• A paid plan. Encoder ingest is on the paid plans. In the 7-day trial the Encoder card shows that RTMP and OBS are on paid plans, and the trial streams from the Browser Studio. See the pricing page.
• Connected channels under Connections.
• Larix Broadcaster on the phone. Softvelum's documentation is at softvelum.com/larix/docs (checked 5 November 2026).

Steps

1. Open the Encoder card on a computer. Click New stream and choose Stream from software like OBS (RTMP / SRT). The address and the key are easier to copy here than to type on a phone.
2. Build the RTMP URL. Larix takes a single connection URL. Softvelum's docs describe it as the server address with the stream name or key added after a slash. The address on the Encoder card already ends with /live/, so paste the key right after it, with no space and no second slash. Use the RTMPS tab if you can; it is encrypted and runs on port 443.
3. Send the URL to the phone privately. For example, a note to yourself in a password manager. Anyone who has the full URL can stream into your broadcast, so do not post it in a group chat.
4. Add the connection in Larix. In Larix's settings open Connections, add a new connection, give it a name, and paste the full URL into the URL field. Make it the active connection.
5. Pick the video settings. Choose H.264 (also called AVC) if Larix offers HEVC as well: our ingest accepts H.264 video and AAC audio only, with a combined bitrate between 2 and 14 Mbps and a keyframe interval between 2 and 10 seconds (Cloudflare Stream: Start a live stream). Set a keyframe interval of 2 seconds and a bitrate your mobile upload holds; 720p is often steadier than 1080p on mobile data.
6. Tick your channels. In StreamLive Pro switch on the destinations in the Channels list and keep the page open on the computer, or open it in the phone's browser.
7. Start streaming in Larix. Within about ten to thirty seconds StreamLive Pro shows that the stream was detected and sends it to the ticked channels.
8. End from StreamLive Pro. Press Stop stream, then stop Larix.

Using SRT from Larix

SRT is the better choice on mobile data, because it recovers lost packets instead of stalling. Copy the SRT address from the Encoder card's SRT tab; the stream ID is already part of that address. If the broadcast shows a passphrase, enter it in Larix's SRT passphrase setting; Softvelum's Larix Grove page lists the passphrase and stream ID among an SRT connection's parameters. Leave Larix in caller mode, since your phone connects to our server. Latency and the passphrase are explained field by field in Stream with SRT from OBS, vMix or a hardware encoder.

WHIP from Larix

Cloudflare, which receives your stream, lists Larix among the apps that can send WHIP (Cloudflare Stream: WebRTC). In StreamLive Pro the WHIP tab is in beta and we have not tested it with an encoder, Larix included. The same Cloudflare page says WHIP inputs do not support restreaming over RTMP or SRT, which is how your broadcast reaches the networks. For multistreaming from Larix, use RTMPS or SRT. More in WHIP from OBS to StreamLive Pro: beta status and setup.

What can go wrong

More checks in My encoder says it is streaming, but there is no picture.

Frequently asked questions

Do I need Larix to use my phone as a camera?

No. StreamLive Pro's phone camera link opens in the phone's browser and adds the phone as a camera in the browser studio. Larix is for streaming from the phone on its own, with manual control or SRT.

What URL do I put in Larix for RTMP?

The address from the Encoder card with the stream key added at the end. The address ends with /live/, so the key goes straight after it.

Can Larix stream to YouTube and Facebook at the same time through StreamLive Pro?

Yes. Larix sends one stream to StreamLive Pro and our servers send it to every channel you ticked, so the phone's upload carries the stream once.

Should I use SRT or RTMP from a phone?

SRT on mobile data or shared Wi-Fi, because it recovers lost packets. RTMPS on a steady connection, because it needs less setup.

Can I use Larix during the trial?

No. Encoders, including phone encoder apps, are on the paid plans. In the trial, use the browser studio and the phone camera link.

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