Patent ID: 6873370
Filing Date: 2005-03-29
Classification: H04N

Abstract:
1. A method for picture-in-picture insertion, in which a sequence of inset pictures is written to a memory and is read from said memory for insertion into a sequence of main pictures, characterized in the steps of: writing an inset picture to the memory under addresses which in each case precede a previously written-in inset picture by a number of N lines, at the beginning of each line to be read, the instantaneous write address and also the speed difference between the write and read operations determining whether, in the line, the write operation can be overtaken by the read operation, and in the case where such overtaking can occur, shifting the read address by N lines to an identical line of a previously written-in inset picture, where the number N is chosen, in a manner dependent on a speed difference between the read pointer and the write pointer, to be at least large enough that a second overtaking cannot occur in a field.