Streaming from macOS with VDO Streamer

Step 2 — Get a signal into the Mac

There are two supported production paths:

Path A — Blackmagic SDI in

Works with any DeckLink or UltraStudio input. The two most common setups:

• External camera or playout → UltraStudio Recorder 3G / Monitor 3G / 4K Mini into the Mac over Thunderbolt. Connect SDI (or HDMI on models that have it) from the source to the Blackmagic device's SDI In.
• UltraStudio 4K Mini / Extreme 3 loopback. These have both SDI In and SDI Out. You can loop a local reference monitor off the SDI Out while simultaneously capturing the input — useful for on-set confidence monitoring without touching the camera.

Once the cable is live and Desktop Video Setup sees the signal, VDO Streamer will list the device under Source → Blackmagic.

Path B — NDI, no capture hardware

If you do not have an SDI card, NDI is the cleanest zero-hardware path. Common ways to generate NDI for VDO Streamer to receive:

• DaVinci Resolve with the VDO NDI Output OFX plugin. Drop the plugin on an adjustment layer and Resolve publishes the timeline over NDI. See Using NDI on macOS with the VDO NDI Output Plugin for installation.
• Any NDI source on the network — an NDI-capable camera (BirdDog, PTZOptics, Sony, Panasonic), OBS with the NDI plugin, or another software encoder.

Both machines must be on the same subnet (or a routed network with an NDI Discovery Server). The Streamer will list all visible sources under Source → NDI.

Other source types are available for quick tests and remote desktop workflows:

• Screen Capture — picks any display or window using macOS's ScreenCaptureKit. Optional system audio capture.
• File — plays back a local video file as if it were a live source.
• Test Signal — SMPTE bars and a handful of synthetic patterns. Useful for validating a room end-to-end before you plug anything in.

Step 3 — Create a Streamer Key

The Streamer Key is how the app proves it is allowed to publish to your account's rooms. It is a long-lived token, one per user, that you paste into the Streamer once.

1. Sign in to vdostream.io.
2. Go to Dashboard → Settings → Streamer Keys.
3. Click Generate New Key.
4. Give it a name (e.g. "Studio Mac" or "Set Cart") so you can revoke it later if the machine is lost.
5. Copy the key. It is only shown once — if you lose it, generate a new one.

Treat it like a password. Anyone with the key can publish to any of your rooms.

Step 4 — Authenticate the Streamer

1. Launch VDO Streamer (it runs in the menu bar and has a main window).
2. In the main window or menu bar, open the Account section.
3. Paste the Streamer Key into the Streamer Key field.
4. Click Connect.

The Streamer calls the VDO API, verifies the key, and pulls down the list of rooms your account can publish to. The list refreshes automatically when you reconnect or hit Refresh Rooms.

If the key is rejected, you will see Invalid streamer key. Double-check the value (no stray whitespace, copied in full) or regenerate it from the dashboard.

Step 5 — Pick a room

Rooms are where viewers watch the stream. The Streamer supports two room types and selects the right defaults for each:

• Colour (P2P) — low-latency, direct peer-to-peer paths. Best for grading review, QC, and any workflow where latency matters more than broadcast reach. Typical audience: 1 – 10 viewers on the same project.
• Editorial — broadcast-style fan-out via VDO's SFU. Higher viewer counts, slightly more latency than Colour. Best for client review sessions, editorial handoffs, and any audience larger than a handful of seats.

Pick a room from the dropdown. The Streamer applies the correct preset defaults (codec, bitrate, chroma, HDR capabilities) for that room type. You can override them in Settings.

Step 6 — Configure the stream

Source

• Select Source: Blackmagic, NDI, File, Screen Capture, or Test Signal.
• For Blackmagic: pick the device from the dropdown. The format (resolution, frame rate, chroma) is detected from the incoming SDI signal automatically.
• For NDI: pick a source from the list of discovered NDI streams on the network.
• For Screen Capture: pick a display or window and optional audio.

Audio

• Audio Source: choose between Embedded (audio carried in the SDI / NDI signal), a specific Core Audio input (any macOS input device — built-in mic, USB interface, Blackmagic ATEM Mini audio, Loopback, BlackHole, etc.), System Audio (macOS's default output, captured via ScreenCaptureKit), or None.
• Audio Codec: Opus (default) or AAC. Opus is lower latency and better quality at the bitrates used for live; AAC is there for compatibility and multichannel.

For a deeper walk-through see Audio settings in VDO Streamer.

Video codec and quality

• Codec: HEVC (default) or H.264. HEVC is mandatory for HDR and for chroma above 4:2:0. Stick with HEVC unless a receiver in your audience cannot decode it.
• Chroma: 4:2:0, 4:2:2, or 4:4:4 (HEVC only). 4:2:2 is the grading-workflow default; 4:4:4 for VFX review or text-heavy screen share.
• Bit depth: 8-bit or 10-bit. 10-bit is required for HDR. For grading review, 10-bit even on SDR is worth the extra bits.
• Bitrate: the room's default is a sensible starting point. The scale goes from ~6 Mbps (1080p SDR 4:2:0 at broadcast quality) up to ~80 Mbps (4K HDR 4:2:2 10-bit reference grade).

HDR

• HDR Mode: Auto, SDR, PQ, or HLG. Auto reads the incoming signal's metadata — if the source is an HDR-tagged NDI stream or an HDR SDI signal with HDR InfoFrame metadata, it picks PQ or HLG automatically. Override to SDR if you want to send an HDR source as tone-mapped SDR.
• Confirm the Detected transfer panel matches what you expect. If it says SRGB but you are grading PQ in Resolve, the colour management chain is wrong — see DaVinci Resolve colour management for NDI output.

Resolution and frame rate

Use the source's native resolution and frame rate whenever possible — the Streamer does not re-scale or frame-convert by default, and any change means a CPU / GPU hit. If you do need to downscale for bandwidth (e.g. a 4K source to a 1080p stream), set it explicitly in Settings.

Step 7 — Stream

1. Confirm the preview in the main window shows your source correctly.
2. Confirm audio is showing activity on the VU meter.
3. Click Start Streaming.
4. The Streamer negotiates transport with the room — QUIC direct first, WebRTC P2P next, QUIC relay, SFU as final fallback — and begins publishing within one or two seconds.
5. Viewers who open the room in their browser or VDO Player will see the stream start as soon as they join.

The status indicator in the menu bar turns green when the publish is live. Click it any time to see a compact summary: transport tier in use, measured bitrate, round-trip time, and frames dropped.

Verifying the stream at the receiver

1. Open the room URL from your dashboard in a browser tab, or launch VDO Player and join the room.
2. Check that video and audio are playing.
3. For HDR: confirm the receiver reports HDR mode in its diagnostics panel. See HDR preview with VDO Player.

Troubleshooting

Blackmagic device does not appear in the Source dropdown Open Blackmagic Desktop Video Setup and confirm it sees the device. If it does, restart VDO Streamer — the device list is polled on launch.

NDI sources list is empty NDI discovery is mDNS / Bonjour. If the source machine is on a different subnet from the Mac running Streamer, configure an NDI Discovery Server or move both to the same LAN. Also confirm the source machine is actually publishing — open another receiver (a second Streamer, OBS, or another NDI-aware tool) on the same subnet and verify it sees the source.

"Invalid streamer key" Regenerate the key from the dashboard. Make sure you copy the full value — they are long, and browsers sometimes silently truncate on copy.

No rooms appear after authenticating Your account has no rooms created yet, or the account you authenticated belongs to a tenant that has none. Create a room from the dashboard and refresh.

Preview is black on a Blackmagic input The SDI signal is not present, or the format is unsupported (rare — Desktop Video handles all standard SMPTE formats). Confirm the signal on a reference monitor by plugging it in directly.

HDR shows as SDR in the Detected transfer panel The source is not tagged HDR. For SDI: enable HDR InfoFrame output on the sending device. For NDI from Resolve: see the colour management guide linked above.

Stream starts, then drops to a lower transport tier Expected behaviour when P2P cannot be established (symmetric NAT, strict corporate firewall). QUIC Relay and SFU both give reliable delivery; the only cost is a small increase in latency. The status indicator shows which tier is currently in use.

High CPU / GPU usage at 4K HDR HEVC 10-bit 4K encoding is expensive even with VideoToolbox. The Mac needs to be Apple Silicon (any M-series chip) or a Mac Pro with adequate thermal headroom. Intel Macs will struggle at 4K HEVC; run at 1080p or switch to H.264 for those machines.

Further reading

• Using NDI on macOS with the VDO NDI Output Plugin — installing the OFX plugin to send NDI from DaVinci Resolve.
• Audio settings in VDO Streamer — every audio option in detail.
• DaVinci Resolve colour management for NDI output — getting the colour chain right end-to-end.
• HDR preview with VDO Player — receiving HDR streams.

Trademark notice

NDI® is a registered trademark of Vizrt NDI AB. DaVinci Resolve® and UltraStudio® are registered trademarks of Blackmagic Design Pty. Ltd. VDO is not affiliated with, endorsed by, or sponsored by Vizrt, Blackmagic Design, or any of their affiliates.