Blackmagic Streaming Encoder SRT setup with Callaba Gateway

May 21, 2026

Written by Iurii Pakholkov

Founder of Callaba. Building cloud video tools for SRT, RTMP, WebRTC, NDI, live routing, monitoring, recording, and production workflows.

Release: Callaba 8.4 · Last updated: May 21, 2026

Blackmagic Streaming Encoder can send a live feed over SRT or RTMP. In a Callaba workflow, the practical SRT path is simple: send the encoder output to a Callaba SRT route, verify the stream in the browser, then use the received feed for recording, restreaming, multiview, playback or API-controlled routing.

This guide is written for Blackmagic Streaming Encoder HD and Blackmagic Streaming Encoder 4K. Use the HD model for HD-first H.264 workflows. Use the 4K model when you need Ultra HD, 2160p workflows or H.265/HEVC tests. For the first test, start with H.264 and a stable HD signal.

Quick answer: how do you send SRT from Blackmagic Streaming Encoder to Callaba?

Create an SRT listener or SRT route in Callaba, open the selected UDP port, then configure Blackmagic Streaming Encoder as the SRT sender. Enter the Callaba server address, UDP port, Key / Stream ID and Passphrase if encryption is used. Start with H.264, confirm incoming bitrate and preview in Callaba, then route the feed to recording, restreaming, multiview, playback or API workflows.

Blackmagic Streaming Encoder handles SDI-to-SRT contribution. Callaba handles cloud ingest, monitoring and workflow routing.

What this setup does

This workflow takes a live SDI signal, encodes it on Blackmagic Streaming Encoder, sends it to Callaba over SRT, and then uses Callaba as the controlled cloud workflow layer.

SRT is the contribution path. The production value appears after Callaba receives the stream and can route it.

The important part is separation of duties. The Blackmagic device creates a clean encoded contribution feed. Callaba gives the operator a place to inspect, route and reuse that feed without changing the encoder every time the downstream workflow changes.

Which Streaming Encoder model?

Blackmagic Streaming Encoder HD and Blackmagic Streaming Encoder 4K are close in workflow, but not identical in practical use.

Choose the model by the workflow. Do not test 4K/HEVC first if you are still proving the route.

Model	Best first test	Use when
Blackmagic Streaming Encoder HD	H.264 HD over SRT	You need a compact HD encoder for SDI live contribution and do not need UHD output.
Blackmagic Streaming Encoder 4K	H.264 HD first, then H.265 / UHD	You need 4K/UHD, HEVC, or higher-end SDI contribution workflows.

Recommended SRT mode

For the first cloud test, use the simplest SRT pattern:

Blackmagic Streaming Encoder as SRT Caller → Callaba as SRT Listener or route receiver

This keeps the public endpoint on the cloud side. The encoder only needs outbound UDP access to Callaba. You do not need to expose the encoder site to inbound traffic.

Example SRT target:
srt://YOUR_CALLABA_IP:5000?streamid=stream1

Blackmagic fields:
Server: YOUR_CALLABA_IP
Port: 5000
Key / Stream ID: stream1
Passphrase: optional, same on both sides

Key rule: treat the Blackmagic Key field as the Stream ID / route key. Keep it simple for the first test, for example stream1. Copy the same value in Callaba, including lowercase letters. Treat it as case-sensitive: if Callaba expects stream1, enter stream1, not Stream1 or STREAM1.

Before you start

Stable SDI signal Confirm the encoder sees the SDI source and correct video standard before debugging SRT.

Video standard Confirm that the SDI signal is stable and uses a supported format such as 1080p, 1080i or 720p. Use 1080p for the first test if your source allows it.

Callaba endpoint Prepare the public IP or DNS name, UDP port and route key in Callaba.

UDP firewall Open the selected UDP port in the cloud security group, host firewall and network policy.

Codec plan Start with H.264 HD. Test H.265 or UHD after the route is stable.

Passphrase If encryption is enabled, use the exact same passphrase on both sides.

Bandwidth Keep bitrate below the real uplink. Leave headroom for retransmissions.

Step 1: create the Callaba SRT route

In Callaba, create an SRT listener or SRT route for the incoming Blackmagic stream. For the first test, keep the route simple:

Name: blackmagic-encoder-main
Mode: Listener / route receiver
Port: one open UDP port, for example 5000
Key / Stream ID: simple value such as stream1
Passphrase: empty for first test, or the same value on both sides if encryption is required

Do not skip the firewall step: SRT uses UDP. If the route port is closed in the cloud security group or host firewall, the Blackmagic encoder will not reach Callaba.

Callaba SRT route setup for Blackmagic Streaming Encoder with UDP port and Stream ID — Local screenshot-style reference: create the Callaba SRT route first, then copy its values into Blackmagic.

Step 2: configure Blackmagic Streaming Encoder

On the Blackmagic side, create or edit a streaming destination profile. Depending on software version and workflow, this may be done in Blackmagic Streaming Setup, a custom streaming XML file, or API-controlled configuration.

Use these values from Callaba: Server, Port, Key, Passphrase, Codec and Quality / bitrate. Use H.264 for the first test.

First test profile:
Protocol: SRT
Server: YOUR_CALLABA_IP
Port: 5000
Key: stream1
Passphrase: empty or same as Callaba
Codec: H.264
Resolution: 1080p or source HD format
Latency: 300–500 ms starting point

Automation note: Blackmagic Streaming Encoder can also be configured through Ethernet Protocol or REST API. This is useful for integrators who need centralized setup, remote control, or automated profile changes. Links to the official Ethernet Protocol and REST API documents are included in the references section.

Local screenshot-style reference: Server, Port, Key, Passphrase and Codec are the fields operators usually need to check first.

Settings table

Connection, route identity, codec and firewall rules must all match.

Setting	Blackmagic	Callaba	Why
Mode	Caller / push	Listener / route	Starts connection from encoder to cloud.
Port	UDP route port	Open UDP port	SRT traffic must reach the server.
Key / Stream ID	stream1	same value	Routes the stream to the right input.
Passphrase	same if used	same if used	Encryption fails if values differ.
Codec	H.264 first	receive / route	Best diagnostic path.
Resolution/FPS	HD first, 1080p if possible	source format should match	Simplifies diagnostics before UHD/HEVC tests.
Latency	300–500 ms start	same recovery policy	Gives recovery time on imperfect networks.

After ingest: what Callaba can do

Browser preview: check whether the feed is arriving with video and audio.
Multiview: place the Blackmagic feed next to other live sources.
Recording: create a cloud-side copy of the received feed.
Restreaming: send the received feed to YouTube, Twitch, Facebook, another SRT target, RTMP, or other outputs.
Playback: generate a web player or HLS path for approved viewers.

Monitoring thresholds

Do not stop at “connected.” Confirm the stream is stable and usable.

Practical thresholds: in good conditions, RTT is often around 20–60 ms. If RTT is consistently above 150 ms or keeps growing, check the network. Packet loss above 1–2% usually means you should increase latency, lower bitrate, or improve the uplink.

Also confirm incoming bitrate, audio presence, codec, resolution, key/Stream ID, passphrase state and downstream route.

Bitrate check: incoming bitrate should be stable and close to the value selected in the Blackmagic profile. If the bitrate drops or swings heavily, check the uplink, mobile network behavior, encoder load and real available bandwidth.

Callaba SRT statistics screen showing connected Blackmagic feed incoming bitrate RTT packet loss codec and preview — Local screenshot-style reference: confirm incoming bitrate and preview before routing the Blackmagic feed downstream.

RTMP option

Blackmagic Streaming Encoder can also be used with RTMP workflows. Use RTMP or RTMPS when the destination platform expects RTMP ingest. Use SRT when you want a stronger contribution path into Callaba first, especially over imperfect networks.

Blackmagic Streaming Encoder → SRT to Callaba → RTMP/RTMPS restream to social platforms

Troubleshooting

Start with the SDI input and basic SRT fields before debugging advanced codec or network behavior.

1. Stream does not appear in Callaba

Confirm the encoder is actively streaming, not only configured.
Check Callaba IP/DNS and UDP port.
Open the selected UDP port in the cloud security group and host firewall.
Confirm the Key / Stream ID exactly matches the Callaba route.

2. SRT connects but no picture appears

Check that the SDI input is stable and recognized by the encoder.
Temporarily switch to H.264 HD and test again.
Check whether the selected resolution or frame rate is supported by the workflow.
Confirm the stream is not routed to the wrong Callaba input.

3. Audio is missing

Confirm audio is embedded in the SDI source.
Check Blackmagic audio settings and source routing.
Check Callaba preview or multiview before debugging downstream playback.

4. Stream is unstable over 4G/5G

Lower bitrate and start with 720p or 1080p H.264.
Increase latency to 500–800 ms for a field test.
Check packet loss and RTT in Callaba.
Test Ethernet separately to isolate mobile network behavior.
For 4G/5G field workflows, prefer a Callaba DNS name over a fixed IP when your mobile path may change carrier or route during reconnects. This makes reconnection and operational changes easier.

FAQ

Can Blackmagic Streaming Encoder send SRT to Callaba?

Yes. Create an SRT listener or SRT route in Callaba, then configure the Blackmagic Streaming Encoder destination with the Callaba server address, UDP port, stream key or Stream ID, and passphrase if encryption is used.

Should I use Blackmagic Streaming Encoder HD or 4K?

Use the HD model when your workflow is HD-first and H.264 is enough. Use the 4K model when you need Ultra HD, 2160p workflows, or H.265/HEVC testing. For first diagnostics, start with H.264 even on the 4K model.

Does Blackmagic Streaming Encoder support RTMP too?

Yes. Blackmagic Streaming Encoder models support RTMP-style publishing workflows as well as SRT. Use SRT when contribution reliability and packet recovery matter, and RTMP or RTMPS when the target platform expects RTMP ingest.

What should I enter in the Blackmagic Key field for SRT?

Use the stream ID or route key expected by Callaba. Keep it simple for the first test, for example stream1, and copy it exactly. Treat the value as case-sensitive.

What SRT mode should I use?

For the first cloud ingest test, use Blackmagic as SRT caller and Callaba as SRT listener or route receiver. This keeps the public endpoint on the cloud side and avoids inbound firewall work at the encoder site.

What codec should I use first?

Use H.264 for the first test. After the SRT path is stable, test H.265 or UHD profiles if your model and workflow require them.

Do I need to open UDP ports?

Yes. SRT uses UDP. Open the selected UDP port in the cloud security group, host firewall, router, or network policy so packets from the encoder can reach Callaba.

Where is the passphrase configured?

The passphrase is part of the SRT streaming profile. If you enable SRT encryption, the same passphrase must be present on both the Blackmagic side and the Callaba side. If you do not use encryption, leave it empty on both sides.

Why does the encoder connect but show no picture in Callaba?

Check the SDI input signal first, then codec, resolution, bitrate, key/stream ID, passphrase, and UDP path. Temporarily use H.264 HD for diagnostics before testing H.265 or UHD.

Can Callaba record the Blackmagic SRT feed?

Yes. After Callaba receives the SRT feed, it can be routed to recording, restreaming, multiview, web playback, or API-controlled workflows depending on your deployment.

Can I use a 4G or 5G phone connection?

Blackmagic lists mobile data via a 4G or 5G phone as a streaming path for the Streaming Encoder line. Test this path under real network conditions and use conservative latency and bitrate for the first field test.

Does Callaba replace Blackmagic Cloud?

No. Callaba is a live video workflow and routing layer. Use it when you need your own SRT ingest, monitoring, recording, restreaming, player delivery, API control, or self-hosted/private cloud deployment.

Is the Blackmagic Key / Stream ID case-sensitive?

Treat the Key / Stream ID as case-sensitive. If Callaba expects stream1, enter stream1 exactly, not Stream1 or STREAM1.

Can I automate Blackmagic Streaming Encoder configuration?

Yes. Blackmagic provides Ethernet Protocol and REST API documentation for Streaming products. This is useful for integrators who need centralized setup, remote control or automated profile changes.

What should incoming bitrate look like in Callaba?

Incoming bitrate should be stable and close to the bitrate selected in the encoder profile. If it drops or swings heavily, check uplink capacity, mobile network behavior, encoder load and available bandwidth.

Next steps

Last updated: May 21, 2026

Try Callaba Gateway with Blackmagic Streaming Encoder

Create an SRT listener in Callaba, send your Blackmagic Streaming Encoder feed to the gateway, and monitor the received stream before routing it to recording, restreaming, multiview, playback, or API workflows.

See SRT server setup Open multiview demo SRT servers API docs