| 摘要 |
<p>A compression/decompression system includes a source (10) of (1:1 60Hz) non-interlaced scanned video signal. A preprocessor (12) constructs (2:1 60Hz) interlaced scanned video signal from the non-interlaced scanned video signal by selection of alternate lines of successive non-interlaced image signals. The interlaced scanned video signal is compressed (14) according to an MPEG protocol of I, P and B frame compression algorithms. I, P and B frame compression is performed such that there are an odd number, greater than one, of B-frames between successive I/P frames (for example the sequence of compressed frames may conform to I, B1, B2, B3, P, B1, B2, B3, P, B1, B2, B3, I, B1,... etc). The I compressed frames, the P compressed frames and alternate B compressed frames (the frames B2 in the exemplary sequence) selectively form (15, 16) a primary compressed (2:1 30Hz) interlaced video signal for reproduction by interlaced scanned receivers. The intervening B-frames selectively form a secondary compressed video. The primary and secondary compressed video signals are received by non-interlaced scanned receivers for reproducing non-interlaced scanned images, while the primary signal alone may be reproduced by interlaced scanned receivers.</p> |
