BlackMagic Decklink Capture

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Device capture/BlackMagic Decklink Capture

For capturing external live video sources, Composer provides a BlackMagic DeckLink Capture input.

Blackmagic Decklink Capture v3 - Supports both Windows and Linux OS. Support for multiple Decklink capture cards.

Note!

Starting with Composer R1 2025, the framerate of the cameras must match the framerate of your Composer project.

  • Show advanced options - show/hide advanced options

  • Input device and channel

    • Input device & channel - Selected input channel

    • Device name - The name of the selected device

  • Options

    • Start playing on startup - Check this option to enable capture at application launch. For autostart of inputs, the Autostart inputs options also must be activated on the application level (See the chapter Runtime Performance)

    • Error on black video - Check this option to trigger an error if the incoming video is black.

    • Capture is genlocked to sync source - When enabled, this option tells Composer that the Decklink input is synchronized to an external genlock signal. In this mode, frame duplication and frame skipping are considered impossible, which allows Composer to optimize capture performance by reducing internal buffering.

    • Keep last frame on lost input - If the DeckLink capture loses the video signal, the last captured frame will be displayed as a still image until the capture resumes.

    • Freeze on pause - if this option is active, the video will be “frozen” instead of empty when playback state is Paused.

    • Use host pinned memory - Used pinned memory will speed up the capture performance.

  • Commands:

    • Start capture - Starts the capture

    • Stop capture - Stops capture

    • Pause/Unpause - Pause/Unpause capture

    • Playback state - Current playback state

  • Still store
    Still store is a feature that allows you to store images to use when capture is stopped or has not been started yet.

    • Still store mode - select when to use the still store image

    • Number of stored images - the number of images stored on disk

    • Newest still store image - datetime of the latest stored image

    • Loaded still store image - name of recently loaded still store image

    • Store - saves the latest captured image to the still store.

  • Performance and properties:

    • Width - captured video width (pixels)

    • Height - captured video height (pixels)

    • # captured frames - The total number of captured frames

    • # frames played back - Current played frames

    • Last capture event - Displays the log message of the most recent event.

  • Icon

    • Icon text - short descriptive text used in the input list. Limited to 5 characters.

  • Audio mixer

    • Hide in the audio mixer - if this option is set, the input will not appear in the audio mixer.

  • Render Tuning:

    • Invisible (Do not render) - Disables rendering. When enabled:

      • The input will not produce any visible output in the scene.

      • It can still be used for programmatic control, automation, or audio routing if applicable.

      • Useful for preparing or testing sources without displaying them live

    • Do not render input - Disables internal rendering, which can help reduce performance load in some cases.

  • Render Options - These options, together with Render Tuning (see Performance and Options), help optimize performance by letting Composer automatically decide whether the input should be rendered.

    When your project’s Render Tuning option is active, Composer manages each input’s rendering automatically for best performance.

    These options allow you to override that behavior and manually decide if this input should be rendered or excluded from the scene.

    Render Tuning vs Render Options:

    • Render Tuning works at the project level (see Performance and Options), automatically managing which inputs are rendered across all Scenes for optimal performance.

    • Render Options work at the input level, letting you manually override or fine-tune how a specific input behaves within Composer’s automatic rendering process

    Additional performance tips

    Beyond the settings covered above, the following resources provide additional guidance on optimizing Composer's performance on your system:

    • Invisible (do not render in scene) - The input will not produce any visible output in the scene, regardless of whether Render Tuning is enabled at the project level.

    • Do not render input

      • Let Composer decide (default) – Composer automatically decides whether the input should be rendered, based on the active Scene and if Render Tuning is enabled.

      • Manual configuration – Allows you to manually control rendering behavior using the Render switch (see below).

    • Render - A toggle switch available only when Manual configuration is selected.

  • Optional TAGS (space separated)

    • TAGS - Add a "tag"  that can be used in the input smart search function. It is possible to add several tags by separating them with a SPACE character.

* Debug properties. Only visible if 'Show Debug Properties' is enabled in Settings.

Audio Configuration and Processing Options

For inputs capable of processing audio, additional audio configuration and processing options are available through the Audio Mixer and the Channel Strip Inspector.

  • Audio Mixer — Monitor levels, adjust gain and pan, mute/solo inputs, and configure auxiliary sends to Audio Channel Strips—all from a centralized mixer-style interface.

  • Channel Strip Inspector — Access advanced audio processing options by selecting the input's mixer strip:

    • Input trim, stereo remapping, and audio delay

    • Channel mapping

    • Gate

    • Low-cut filter

    • Equalizer (5-band parametric EQ)

    • Compressor

    • Limiter

See Audio Mixer and the Channel Strip Inspector for more detailed information.

Product Compatibility

The following capture cards are currently supported:

  • BlackMagicDesign Decklink Duo 2

  • BlackMagicDesign Decklink Quad 2

  • BlackMagicDesign DeckLink Quad HDMI Recorder (Capture v3 and later)

  • BlackMagicDesign DeckLink 8K (Capture v3 and later)

  • BlacMagicDesign Mini Recorder (Capture v3 and later)

Other Decklink versions might work, but are not tested or officially supported.

Using multiple capture cards is only supported by the input "Blackmagic Decklink Capture v3" and later.

The two alternatives, Blackmagic Decklink Capture v2, Blackmagic Decklink Capture (Windows Only), have been deprecated. However, if you have older projects using these DeckLink input versions, they will still work and appear in the list of added inputs. We recommend upgrading them to Blackmagic Decklink Capture version 3.

Recommendation!

Using too many Blackmagic Decklink inputs simultaneously can impact the performance of Composer.

Hints!

  • If you are unsure of the incoming video format, use Blackmagic Media Express to detect it.

  • Use the keyboard shortcut CTRL+P to pause all running inputs, including Decklink Capture.

Note!

When using two DeckLink cards of the same type, the cards may be mixed up when restarting the server. To prevent this, use the Label in Desktop Video Settings to name the connectors

For more information and driver updates, please visit https://www.blackmagicdesign.com/support/.