Device capture/BlackMagic Decklink Capture

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

Currently, there are three different alternatives when adding a new device capture.

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

• Blackmagic Decklink Capture v2 - Supports both Windows and Linux OS. Do not support multiple capture cards.

• Blackmagic Decklink Capture (Windows Only) - Only supports Windows OS  

• Input channel - selected input channel

• Device name - the name of the selected device

• 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) 

• Black video detector:

  • Warn on black video input - Checkbox for enable/disable Black video detector. Will generate a warning if the below criteria are fulfilled.

  • Black video ratio warning threshold (%) - Input field 90-100%. Generates a warning if black pixels ratio in video is above configured value.

  • BlackVideoFrameCountThreshold - Number of frames for detecting black video.

• Commands:

  • Start capture - starts the capture

  • Stop capture - stops capture

  • Pause/Unpause - Pause/Unpause capture

  • Playback state - current playback state

• Performance and properties:

  • Number of captured frames - the total number of captured frames

  • Number of frames played back - current played frames

  • Last autodetect format change - if the component can detect the incoming video format, the name of the video format will be displayed

  • Max capture queue size (ms) - defines the number of capture buffers. The default value is 2. A longer buffer will introduce a longer latency but more stable capture, and vice versa.

  • Current video capture queue size (ms) - the current queue size for video capture

  • Current audio capture queue size (ms) - the current queue size for audio capture

  • Number of buffer empty events - should be zero when capturing a stable video input (with average CPU load)

  • Number of inputless frames - number of inputless video frames captured 

  • Number of audioless frames captured - number of inputless audio frames captured 

  • Number of audioless renders performed - number of audioless renders performed

  • Number of audio flushes performed - number of audio flushes performed

  • Number of blocked audio enqueues performed - number of blocked audio enqueues performed 

  • Number of automatic restarts performed - the total number of automatic restarts

  • Number of black pixels last frame - the total number of black pixels found in the last frame captured.

  • Number of black pixels (%) last frame - the percentage of black pixels found in the last frame captured.

  • Last black pixel event - displays information on the last black pixel event. Example:

  • About - Information about the input.

• Resolution:

  • Width - captured video width (pixels)

  • Height - captured video height (pixels) 

Product Compatibility

The following capture cards are currently supported:

• BlackMagicDesign Decklink Duo 2

• BlackMagicDesign Decklink Quad 2

• BlackMagicDesign DeckLink Quad HDMI Recorder (Capture v3) 

• BlackMagicDesign DeckLink 8K (Capture v3)

  
  

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".

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