摘要 |
A converter receives a computer graphics signal from a PC and provides from it a video signal for display or recording. Analogue RGB signals are digitised and applied to a vertical filter and rate buffer. The rate buffer needs only one to three lines of storage capacity. The received graphics signal is a VGA 640x480 non-interlaced mode signal, and the rate buffer halves the line rate and produces an interlaced output. Such a signal can be treated as a video signal, after reconversion to analogue form. The vertical filter provides a degree of vertical averaging to remove flicker. In a preferred store using three line-store FIFOs, input lines are applied to them in the sequence A,B,C,B,A, and so on.
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