4 title: Blackmagic Design DeckLink Output
6 copyright: Copyright (C) 2011 Daniel R. Dennedy
14 Output audio and video using Blackmagic Design DeckLink SDI or Intensity
17 Please ensure that you use a MLT profile that is compatible with a broadcast
18 standard which the card you are using supports.
20 - Only internal keying is supported at this time.
21 - Only 8-bit Y'CbCr or RGBA (key) is supported at this time.
23 - identifier: argument
37 This controls the amount of buffering in the DeckLink driver/library.
38 Increase this if you get video tearing or choppy audio. However, as
39 you increase the amount, you increase the risk of audio and video
40 becoming out of synchronization.
53 Keying is the process of compositing MLT output over a live SDI input.
54 The alpha channel of the MLT video controls the transparent areas, and
55 the keyer supports alpha-blending. You can not control the compositing
56 rectangle. Rather, the entire MLT output overlays the entire video
57 input. Therefore, you must use MLT's compositing services to control
58 the size and position. The value 1 enables the internal keyer, the
59 value 2 enables the external keyer, and the value 0 disables it.
67 - identifier: keyer_level
71 This controls the level of blending between the key and the input video.
72 1 is fully opaque and something near 0 is transparent. However, absolute
73 0 is considered as "not supplied" and also fully opaque. 0.5 is an
74 evenly balanced blending of the key and input video.
84 title: Number of devices
89 - identifier: device.*
91 description: The model name of each device that provides output.