11 · Outputs: SRT & NDI | RePro Help Center

Every broadcast row can push out up to two independent outputs, labelled by row letter and number (A1 / A2, B1 / B2, and so on). Each output picks its own transport (SRT, NDI, or DeckLink/SDI) and destination, so one row can send SRT to a remote receiver and publish an NDI source on your LAN at the same time.

This page covers picking a transport, filling in its settings, and starting/stopping. Codec and bitrate live behind the encoder badge — see Encoding, bitrate & color.

Where to find outputs

Each enabled output shows a sub-row indented under its row, with a transport pill (SRT / NDI / SDI), the destination, an encoder badge, a START / STOP button, and a status light.

Turn an output on or off with the 1 / 2 buttons in the row header.
Open its settings by clicking the transport pill or the destination chip.

Stop an output before reconfiguring it — its controls lock while it's running, connecting, or in error.

See also Rows and sources and The main window.

Send an output to a remote SRT receiver (Caller)

Use Caller mode when Pulsar should dial out to a remote SRT host — the most common setup.

Turn the output on with its row-header number button.
Click its transport pill or chip to open settings, then choose the SRT tab and Caller.
Paste the receiver's address into SRT URL (must start with srt://).
Adjust SRT latency if needed (default 400 ms), and leave Audio encoding on AUTO.
Click Apply, then START. Watch the light go orange (connecting), then green (connected).

Let a remote caller pull from this machine (Listener)

Use Listener mode when Pulsar should open a local port and wait for someone to call in.

In the output's settings, choose the SRT tab, then Listener.
Confirm the auto-filled IP address and Port (change the port only if you must).
Optionally set a Passphrase, or click New to generate one.
Copy the read-only Full URL (for caller) — or click QR for a scannable code — and send it to whoever will connect.
Click Apply, then START to open the listener.

If two rows try to listen on the same port, Pulsar bumps one automatically, so the saved port may differ from what you typed.

Publish an output as an NDI source on the LAN

In the output's settings, choose the NDI tab.
Set a friendly NDI output name (or leave it blank for the default).
Leave Clock video and Clock audio on unless your workflow needs them off.
Click Apply, then START.

The source appears in NDI viewers as <MACHINE NAME> (<output name>) — the settings window shows a live preview of how it will read.

NDI is 8-bit. 10-bit/HDR video is downconverted and the bitrate setting doesn't apply. For verified 10-bit HDR, use SRT or SDI. See also NDI as a source.

Play out to an SDI card (DeckLink)

Choose the DeckLink (SDI) tab. Pick the Output device and Output mode (e.g. 1080p25), optionally tick Embed audio on card (2 / 8 / 16 channels), and tick HDR (10-bit) with PQ or HLG if you need it. Click Apply, then START.

Requires a Blackmagic card and driver. If two rows target the same card, an amber warning appears — only one can drive it at a time.

Start or stop several outputs at once

Use the footer buttons:

START ALL / STOP ALL RUNNING — every output across all rows.
START SELECTED (n) / STOP SELECTED (n) — only the outputs you've ticked.

To select outputs, tick the checkbox on each sub-row (or a row's header checkbox to grab all of its outputs), then click the matching SELECTED button.

STOP ALL RUNNING is a manual stop — those outputs stay down until you start them again.

Reading the sub-row

Transport pill — SRT, NDI, or SDI. Click to open settings.
Destination chip — SRT shows a masked URL with a CALL / LISTEN badge; NDI shows the name; DeckLink shows DeckLink <n> · <mode>.
SRT health icon (chain link) — click when idle to probe the connection (RTT), or when live for stats (Mbps / fps / dropped / uptime).
Encoder badge — codec and bitrate, e.g. H264|Auto. Click to open Encoding.
Status light — grey = stopped, orange = connecting, green = connected, red = error/reconnecting.

For watching outputs once they're live, see Monitoring and preview.

Tips & gotchas

SRT caller URLs must start with srt:// — otherwise Apply shows "Enter a valid SRT URL".
STOP works even in the error state, so you can always clear a stuck output.
Same SRT endpoint: if two rows use the same caller URL, an amber dot appears on the health icon. It's allowed, but only one can stream to that endpoint at a time.
Output 2 starts at 20 ms latency while Output 1 defaults to 400 ms — bump Output 2 if you need more buffer.
Rows lock while their outputs run — stop them before reordering rows or changing a row's input.
Streaming needs GStreamer. If outputs won't start, open About → System Dependencies & Firewall. See Installation and setup and Troubleshooting.

Encoding, bitrate & colour — codec, bitrate and colour behind the encoder badge.
NDI as a source — bringing NDI in, plus more on NDI limits.
SRT as a source — receiving SRT in.
Monitoring and preview — watching outputs once they're live.
Troubleshooting and the Glossary.