Video apparatus nowadays use video information from digital sources. For instance, a video player reads video information from digital media where the information is previously digitally recorded. Such a digital medium is for instance a tape recorded according to the D-VHS standard, a hard-disk drive (HDD) or an optical disc (like DVD) where a program stream is recorded. (As another example for a video apparatus with digital source, a set-top box receives a digital stream from a digital front-end including tuner and demodulator.)
Such a video player mainly comprises a media player (digital source) to read (or reproduce) the video digital stream from the medium and a video encoder to generate an analogue video signal from the video digital stream (i.e. to convert the digital stream into an analogue signal according to a known standard like CVBS-PAL, SECAM or NSTC, S-Video or RGB). The analogue video signal is then ready to be displayed for instance by a conventional TV set. An example of such a video apparatus is described for instance in U.S. Pat. No. 6,229,951.
Some video apparatus can display two video sequences at the same time in a picture-in-picture (PIP) fashion: a first video sequence is displayed on a first part of the screen, generally on the whole screen (the first video sequence is then called the parent image), and a second video sequence is displayed on a second part of the screen, generally superimposed on the first video sequence on a limited part of the screen (whereby the second video sequence is called the child picture).
To realise such a PIP function, known video apparatus have two video sources and at least a specific video circuit for reduction of the size of the video source used as a second video sequence (child picture), as described in patent application EP 0 406 698.
USPTO Backgrounds
USPTO Backgrounds