Vela CineCast 2000-0422, Installation And User Manual

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90 CineCast Quad Pro Version 2.6 Installation and User Manual
0047 Video/Audio Fade
Fade to Black
Normally the video fade is a mixing operation using an alpha mixer between the
current video source and the new video source (specified in Video Source field).
Video Fade using alpha mixing is given by the equation:
Output Video =
Q
(Source_A) + (1 -
Q
)(Source_B)
Where Source_A = the current video source
Source_B = the new video source
Q
= alpha (mix value is varied from 1 to 0 over the specified
video fade time).
With “Fade to Black” set, the current video source will fade to black (or background
color) and then fade from black (or background color) to the new video source.
Background color is specified in command 0033h.
Video Fade Time
Video Fade time is specified in terms of video frames. The maximum fade time is
255 frames (8.5 seconds NTSC or 10.2 frames PAL). However, the longest audio
fade is limited to 5.46 seconds. A video fade time of 0 or 1 performs an immediate
video switch instead of a video fade.
Audio Fade Enable
This bit must be set to enable audio fading operation. When cleared no audio switch
or fade will occur.
Primary and Secondary Audio Source
Source Select Name Source
000b Source 0 IBM Decoder Audio
001b Source 1 Crystal Audio Output No. 1
010b Source 2 Reserved
011b Source 3 Adjacent Channel IBM Decoder Audio
100b Source 4 Adjacent Channel Crystal Audio Output No. 1
101b Source 5 Reserved
110b Reserved Reserved
111b Reserved Reserved