Digital vcr with non-standard speed playback

摘要

A digital video cassette recorder (300) records a high definition signal having an MPEG compatible structure, such as a proposed Grand Alliance signal. In the recorded format an advanced television frame occupies ten recorded tracks. Reproduction at speeds other than the recorded speed is termed "Trick Play". Reproduction in a "Trick Play" mode necessitates a reproducing head crossing a plurality of recorded tracks. However, since the advanced television signal is structured as groups of pictures comprising one intraframe coded frame and a plurality of predicted frames, many of the recorded tracks contain data representing predicted frames. Thus an advanced television signal reproduced in "Trick Play" may represent a jumble of unrelated data segments. Operation in "Trick Play" may be facilitated by the selection of predetermined replay speeds and the allocation of specific locations within each track from which data may be reproduced. These specific track locations are utilized during recording to place advanced television image data for reproduction during "Trick Play" operation. For generating the "Trick Play" image data the digital video image representative signal is compressed (200) to have a data rate suitable for recorded placement at the specific track locations. The data for the digital video image representative signal and the "Trick Play" image data are multiplexed (340) for recorded placement on said magnetic tape (504) such that said "Trick Play" image data is located at said specific track locations.