Abstract: A video decoder transcodes video data from various input formats to a predetermined output format. Input data may be standard definition data or MPEG2 compressed data. Standard definition data are rearranged into block format to be compatible with the decoder's single display processor. The display processor selectively processes and conveys either MPEG2 format data or non-MPEG2 format data to a display device. A block based frame memory stores MPEG2 and non-MPEG2 pixel block data, as well as standard definition data in raster line format during processing.

Abstract: Apparatus for displaying a combined image of an auxiliary image and a main image includes a source of a main image signal and a source of samples representing an auxiliary image signal. A quincunx subsampler is coupled to the auxiliary image sample source and the quincunx subsampler. The sample combiner combines the main image signal and a signal representing the quincunx subsampled samples to generate a signal representing a combined image of the main and auxiliary images.

Abstract: Apparatus for combining an auxiliary image and a main image includes a source of a main image video signal and a source of samples representing an auxiliary image video signal having successive fields. A quincunx subsampler is coupled to the auxiliary image sample source and subsamples the auxiliary image samples in either a first sample pattern in which samples are taken at a first set of horizontal locations, or a second sample pattern in which samples are taken at a second set of horizontal locations substantially midway between the first set, all in response to a control signal. A signal combiner is coupled to the quincunx subsampler and the main image signal source, and combines the main image signal and a signal representing the quincunx subsampled auxiliary image samples to generate a signal representing a combined image of the main and auxiliary images.

Abstract: Apparatus for combining an auxiliary image and a main image includes a source of a main image signal and a source of samples representing an auxiliary image signal. A subsampler selectively subsamples the auxiliary image samples in either a quincunx subsampling pattern or a rectangular subsampling pattern. A signal combiner combines the main image signal and a signal representing the subsampled auxiliary image samples to generate a combined image signal. A control circuit generates a freeze control signal for the subsampler which conditions it to take samples in the rectangular subsampling pattern during a freeze frame operation, and in the quincunx sampling pattern otherwise.

Abstract: In order to selectively reduce the size of an auxiliary image, such as may be displayed within main image during a so called "picture-in-picture" or "PIP" mode of operation of a television system, a fixed amount of the auxiliary image is caused to be cropped from the auxiliary image without changing the compression ratio of the compressed auxiliary video signal from which the auxiliary image is derived.