title: Blackmagic Design DeckLink Output
media types:
Audio Video
description: Output audio and video using Blackmagic Design DeckLink SDI or Intensity HDMI cards.
version: 4
creator: Dan Dennedy
copyright: Copyright (C) 2010-2026 Meltytech, LLC
license: LGPL
Please ensure that you use a MLT profile that is compatible with a broadcast standard which the card you are using supports. HDR output metadata follows the consumer's color transfer characteristic. When color_trc is set to arib-std-b67, the DeckLink output advertises HLG. When color_trc is set to smpte2084, the DeckLink output advertises PQ and the HDR static metadata properties documented below are applied. Any other transfer clears HDR metadata and advertises SDR.
title: Card
type: integer
readonly: no
required: no
minimum: 0
default: 0
widget: spinner
title: Pre-roll Count
description:
This controls the amount of buffering in the DeckLink driver/library. Increase this if you get video tearing or choppy audio. However, as you increase the amount, you increase the risk of audio and video becoming out of synchronization.
type: integer
readonly: no
required: no
minimum: 2
default: 3
unit: frames
widget: spinner
title: Enable Keyer
description:
Keying is the process of compositing MLT output over a live SDI input. The alpha channel of the MLT video controls the transparent areas, and the keyer supports alpha-blending. You can not control the compositing rectangle. Rather, the entire MLT output overlays the entire video input. Therefore, you must use MLT's compositing services to control the size and position. The value 1 enables the internal keyer, the value 2 enables the external keyer, and the value 0 disables it.
type: integer
readonly: no
required: no
minimum: 0
maximum: 2
default: 0
title: Key Opacity
description:
This controls the level of blending between the key and the input video. 1 is fully opaque and something near 0 is transparent. However, absolute 0 is considered as "not supplied" and also fully opaque. 0.5 is an evenly balanced blending of the key and input video.
type: float
readonly: no
required: no
minimum: 0
maximum: 1
default: 1
widget: slider
title: Number of devices
type: integer
readonly: yes
required: no
minimum: 0
title: Device model
description:
The model name of each device that provides output.
type: string
readonly: yes
required: no
title: Use sliced swab operation
description:
This option enables multithreaded parallel swab frame data operation
type: boolean
readonly: no
required: no
minimum: 0
maximum: 1
default: 0
widget: checkbox
title: Colorspace
description:
Set the output colorspace metadata. BT.2020 maps to DeckLink Rec.2020, BT.601 maps to DeckLink Rec.601, and all other values default to Rec.709.
type: integer
readonly: no
required: no
values:
title: Transfer characteristic
description:
Set the output transfer characteristic metadata. Use arib-std-b67 for HLG or smpte2084 for PQ HDR10-style signaling. Any other value is treated as SDR and clears the DeckLink HDR metadata flag.
type: string
readonly: no
required: no
values:
title: HDR primary red X
description:
PQ-only static HDR metadata. Red display primary chromaticity X.
type: float
readonly: no
required: no
minimum: 0
maximum: 1
default: 0.708
title: HDR primary red Y
description:
PQ-only static HDR metadata. Red display primary chromaticity Y.
type: float
readonly: no
required: no
minimum: 0
maximum: 1
default: 0.292
title: HDR primary green X
description:
PQ-only static HDR metadata. Green display primary chromaticity X.
type: float
readonly: no
required: no
minimum: 0
maximum: 1
default: 0.17
title: HDR primary green Y
description:
PQ-only static HDR metadata. Green display primary chromaticity Y.
type: float
readonly: no
required: no
minimum: 0
maximum: 1
default: 0.797
title: HDR primary blue X
description:
PQ-only static HDR metadata. Blue display primary chromaticity X.
type: float
readonly: no
required: no
minimum: 0
maximum: 1
default: 0.131
title: HDR primary blue Y
description:
PQ-only static HDR metadata. Blue display primary chromaticity Y.
type: float
readonly: no
required: no
minimum: 0
maximum: 1
default: 0.046
title: HDR white point X
description:
PQ-only static HDR metadata. Display white point chromaticity X.
type: float
readonly: no
required: no
minimum: 0
maximum: 1
default: 0.3127
title: HDR white point Y
description:
PQ-only static HDR metadata. Display white point chromaticity Y.
type: float
readonly: no
required: no
minimum: 0
maximum: 1
default: 0.329
title: HDR mastering max luminance
description:
PQ-only static HDR metadata. Maximum mastering display luminance.
type: float
readonly: no
required: no
minimum: 1
maximum: 65535
default: 1000
unit: cd/m2
title: HDR mastering min luminance
description:
PQ-only static HDR metadata. Minimum mastering display luminance.
type: float
readonly: no
required: no
minimum: 0.0001
maximum: 6.5535
default: 0.01
unit: cd/m2
title: HDR MaxCLL
description:
PQ-only static HDR metadata. Maximum Content Light Level.
type: float
readonly: no
required: no
minimum: 1
maximum: 65535
default: 1000
unit: cd/m2
title: HDR MaxFALL
description:
PQ-only static HDR metadata. Maximum Frame-Average Light Level.
type: float
readonly: no
required: no
minimum: 1
maximum: 65535
default: 400
unit: cd/m2
title: Stop automatically
description:
Whether to stop playback at the end of the producer or when playback is paused.
type: boolean
readonly: no
required: no
widget: checkbox
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