Tektronix 2200 Manual Do Utilizador

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NOTE:  
This appendix applies specifically to the Model 2200, Model 
3000, and Model 4000 Switchers, but the general principals discussed 
here may apply as well to other switchers and other devices.
Introduction
The purpose of this appendix is to explain what shaped video and 
unshaped video are, where and why they are used, and what you 
need to do so your equipment will handle them properly.
What are Shaped and Unshaped Video?
Shaping and unshaping are generally involved only in keying and 
compositing situations.
Whenever a key is performed, there are always three signals: the 
key source, the key fill (fill video), and the background video. The 
key signal cuts a hole in the background, into which the fill video 
is inserted. Devices such as character generators often output both 
the key signal and the fill video.
Appendix A — Shaped and 
Unshaped Video
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