| 摘要 |
<p>A conventional 2-1 interlaced (nominally 50 Hz field rate or nominally 60 Hz field rate) television signal is converted to a form suitable for display on a progressively-scanned variable-frame-rate high-resolution computer-type monitor. First, a succession of progressively-scanned video frames is derived from the interlaced television signal and each frame is repeated at least twice in succession. When the interlaced television signal is derived from a motion picture source, the progressively scanned frames are derived by merging opposite polarity fields derived from the same motion picture frame. For other sources, other interlace-to-progressive scan techniques, such as line duplication or line interpolation, are employed. The sequences of repeated progressively-scanned frames are written into a two frame memory at rate derived from the timing of the progressively-scanned video frames and are read out at a rate derived from the timing of the monitor's frame rate. Frames are skipped or duplicated in order to prevent memory underflow or overflow. Motion-discontinuity-free video displays at refresh rates from 50 Hz to 100 Hz, for 50 Hz inputs, and from 60 Hz to 120 Hz, for 60 Hz inputs may be achieved.</p> |
