Vorrichtung zur Bestimmung eines effektiven Bildteils eines Videosignals mit hoher Auflösung bei der Darstellung auf einem Bildschirm mit einem anderen Format.

摘要

In an apparatus for converting received video signals of a first format, which has a first number of horizontal lines in a field or frame and a picture display of a first aspect ratio, to video signals of a second format, which has a second number of horizontal lines in a field or frame and a picture display of a second aspect ratio: an analog-to-digital converter (2) converts the received video signals of the first format to digital video signals, a memory (6) has addresses at which there are written at least a field of the digital video signals of the first format, whereupon, a reading circuit (7) reads from the memory (6) addresses less samples of the digital video signals than were written in the memory (6) and the digital video signals thus read from the memory (6) are converted back to analog form, and a controller (9 ) is provided for variably determining a start address of the addresses in the memory (6) from which video signal data are read. In the case where the first aspect ratio is larger than the second aspect ratio, the selection of the start address determines a portion or portions of the picture display of the first aspect ratio to be omitted at least at one side of the picture display of the second aspect ratio.