How to Set Up DeckLink (Blackmagic Design) Capture and Output

How to Set Up DeckLink (Blackmagic Design) Capture and Output

Backstage supports Blackmagic Design DeckLink cards for both SDI/HDMI capture (input) and SDI/HDMI playout (output). This guide covers creating a DeckLink capture asset, configuring a DeckLink output adapter, and setting up audio.

Before you start

• A Blackmagic Design DeckLink card installed in your server (PCIe)
• Blackmagic Desktop Video drivers installed and up to date (see Blackmagic Design support site)
• The card appears in Blackmagic Desktop Video Setup utility before launching Backstage
• A Backstage project open with at least one Surface (for capture) or at least one Projector routed to an Output (for output)

Steps

1. Create a DeckLink capture asset

In the Assets window, expand the Capture Input section. Right-click and select Add DeckLink Capture Card. A new capture asset appears in the list.

2. Select the DeckLink device

Select the new capture asset. In the Inspector, the DeckLink Capture Input section appears. Use the Device dropdown to choose which DeckLink card to capture from. Only cards that support capture are listed. If you have multiple DeckLink cards, each appears by its model name.

3. Choose the video input connector

Use the Input dropdown to select the physical input connector: SDI, HDMI, Optical SDI, Component, Composite, or S-Video. The available options depend on your card model. Select Auto to let the driver detect the active input automatically.

4. Configure audio capture

Use the Audio Input dropdown to select the audio source: Embedded (default for SDI/HDMI), AES/EBU, Analog, Analog XLR, Analog RCA, or Microphone. Set Audio Channels to the number of channels you want to capture (0 to 16). Audio is captured at 48 kHz and appears as an audio stream attached to the capture asset. You can route it to an Audio Channel in the Sequencer.

5. Verify signal detection

Once a valid signal arrives on the selected input, the Inspector shows the detected resolution, frame rate, and pixel format. Backstage auto-detects the incoming signal format and adjusts automatically. If no signal is present, the Inspector shows No signal detected.

6. Use the capture asset in your project

The capture asset works like any other asset. Drag it onto a Surface, or place it as an Event on a Video Channel in the Sequencer. The live input feeds through the same rendering pipeline as file-based media.

7. Create a DeckLink output

Open the Outputs window. Expand the DeckLink section and click the + (create) button. A new DeckLink output slot appears in the list.

8. Configure the DeckLink output

Select the DeckLink output. In the Inspector, the DeckLink section appears with these settings:

• Device — choose which DeckLink card to output through (only cards that support playback are listed)

• Display Mode — select the output resolution and frame rate (e.g. 1080p59.94, 4K 2160p30). The dropdown shows all modes supported by the selected card.

• Output connector — if the card has multiple output connectors (SDI + HDMI), select which one to use. Auto lets the driver decide.

9. Route a Projector to the DeckLink output

Open the Video Routing window. The DeckLink output appears as a column. Check the cell at the intersection of your Projector (or Display) row and the DeckLink output column to route the rendered image to the DeckLink card.

Capture settings explained

Output settings explained

Supported pixel formats (capture)

Backstage auto-detects the incoming pixel format. The following formats are handled natively with GPU format conversion:

• 8-bit YUV 4:2:2 (UYVY) — most common SDI format

• 10-bit YUV 4:2:2 (V210) — broadcast-standard 10-bit SDI

• 8-bit BGRA — standard HDMI 8-bit RGB

• 8-bit ARGB

• 10-bit RGBX LE (R10l) — 10-bit RGB little-endian packed

• 12-bit RGB LE — 12-bit RGB little-endian

Big-endian RGB formats (r210, R10b, 12-bit RGB BE) are supported via CPU fallback conversion. These are functional but less efficient.

Use a DeckLink device as a hardware reference clock

A DeckLink output can discipline Backstage's global system clock against the card's hardware reference clock. This gives you a stable, video-sync-derived timebase for the scheduler, media playback, and PTP synchronization across a multi-server cluster.

When to use a DeckLink reference clock

• You need frame-accurate sync between video output and other time-sensitive systems (audio, lighting, show control).

• You run a multi-server PTP cluster and want the grandmaster's clock locked to a hardware video reference rather than a free-running OS clock.

• Your DeckLink card receives an external genlock or blackburst reference and you want Backstage to follow that timing.

1. Create and start a DeckLink output

The DeckLink device must have a running output before it can serve as a clock source. Follow the DeckLink output steps earlier on this page and confirm the output is active (no errors in the Log).

2. Open Settings and go to Clock

Open Settings (via the menu or toolbar) and expand the Clock section.

3. Select the DeckLink device as the local clock source

In the Local clock source dropdown, open the DeckLink group and select your device by name. If the device name appears in red, the DeckLink output is not running — go back and verify it is created and started in the Outputs panel.

4. Verify the clock is disciplined

The Time readout at the top of the Clock section now follows the DeckLink card's hardware reference clock. A Time:Clock node in the Node Editor set to GlobalClock mode reads from this same disciplined clock.

How it works

When a DeckLink device is selected as the clock source, Backstage samples the card's hardware reference clock on every completed frame. The system clock follows this external timebase using a slew-limited, median-filtered tempo follower — it never jumps or steps, even if the external source has a brief glitch. The result is a smooth, hardware-locked timebase for the scheduler, media playback, and audio engine.

In a PTP cluster, the disciplined local clock participates in the PTP grandmaster election. If this server wins, all other Backstage instances synchronize to the DeckLink-derived timebase, keeping the entire installation locked to the hardware video reference.

Reference clock troubleshooting

• Clock source shown in red — the selected DeckLink device has no active output. Create and start a DeckLink output on that device in the Outputs panel.

• ASIO clock was cleared unexpectedly — selecting a DeckLink clock source automatically deselects any ASIO clock source. Only one external source can be active at a time.

• Time:Clock node does not show DeckLink time — the DeckLink reference clock disciplines the global system clock, not a separate clock mode. Set the Time:Clock node to GlobalClock to read the disciplined time.

[USER-ACTION-REQUIRED: Attach a screenshot of the Settings > Clock section showing the Local clock source dropdown with a DeckLink device selected]

Common mistakes

• Card not detected in Backstage — Backstage discovers DeckLink cards at startup using the Blackmagic Desktop Video SDK. If your card does not appear in the Device dropdown, check that Blackmagic Desktop Video drivers are installed and that the card is visible in the Blackmagic Desktop Video Setup utility. Restart Backstage after installing or updating drivers.

• No signal detected on a connected input — Verify the correct Input connector is selected (SDI vs HDMI). If the source device is not sending a signal yet, the Inspector shows "No signal detected" until a valid signal arrives. Also check cables and ensure the source is set to the correct output mode.

• Output shows black or no signal on the downstream device — Confirm the Display Mode matches what the downstream device expects. A 4K mode on a 1080p-only monitor will produce no signal. Also verify that a Projector or Display is routed to the DeckLink output in the Video Routing window.

• Driver version mismatch — Backstage uses the DeckLink SDK for device communication. Older driver versions may not support newer card models, or may have bugs with auto-detection. Always use the latest Blackmagic Desktop Video release.

• Using the same DeckLink sub-device for both capture and output simultaneously — A single DeckLink sub-device (as seen in the Device dropdown) supports either capture or playback at a time, not both. Cards with multiple sub-devices (e.g. DeckLink Quad 2) expose separate entries for each direction.

• Audio channels set to 0 — Setting Audio Channels to 0 on a capture asset disables audio capture entirely. If you expect embedded audio, set this to at least 2.

Tips

• Use the Test Pattern checkbox on the output to verify signal delivery before routing content. It generates SMPTE color bars in the card's native pixel format.

• DeckLink capture supports frame blending for smooth playback when the capture frame rate differs from your project frame rate.

• For 4K SDI output, select Quad Link in the SDI Link setting. Check your downstream device's documentation for whether it expects Square Division or 2-Sample Interleave.

• Backstage uses zero-copy capture when possible — the DeckLink SDK writes directly into Vulkan staging memory, eliminating CPU-side copies. This is automatic and requires no configuration.

• Keep Zero-Copy Output enabled (the default) unless you experience issues. It uses pinned host memory to skip an extra memory copy on the output path.

Related

Supported Capture Hardware — overview of all supported capture input types

Capture and Re-map a Video Stream — capture and re-map a live video stream

How to Synchronize Playback Across Multiple Servers (PTP & Observer) — How to Synchronize Playback Across Multiple Servers (PTP & Observer)

Supported Media Types — full list of supported media types in Backstage

Combine multiple Capture Inputs to one Asset — combine multiple capture inputs to one asset