| 摘要 |
A system of sending digital high definition television pictures and sound in a limited bandwidth using the principle of analyzing and sending changes in pictures and coded instructions rather than entire pictures. Delaying the presentation of the pictures slightly permits major picture changes and sound to be sent at a lower bit rate over a longer period of time. Non-changing areas of the pictures are sent to the receiver and remain on the screen until changes occur or refresh is desired. When TV cameras shift orientation, backgrounds of pictures or objects which do not change are shifted on the receiver with appropriate codes rather than repeating the entire picture. Fast changing portions of pictures are determined and sent more frequently than slower or non-changing ones. Sound information is acquired and compared to libraries of sound fragments. A code (stored or newly created) referring to the appropriate fragment is then sent with the picture information in a series of picture, command/control, and sound data packets. Reception is made with data receiver devices attached to signal reception devices. Presentation of pictures at the receiver is made from bank switched memory prior to D/A conversion. This allows screen data updates to be made prior display. Major screen changes are built up in a special memory bank over a longer period of time before display on the screen. Sound data is matched to the fragment library and played at the appropriate time by a sound reproduction unit.
|
