摘要:
An MPEG decoder (14, 18, 22) in a high definition television receiver decodes and decompresses MPEG coded data to produce decompressed image pixel blocks, and includes a motion compensation network (90...) coupled to a frame memory (60) to produce finally decoded pixel data for display. The decompressed MPEG data is recompressed by plural parallel recompressors (40, 42) prior to storage in frame memory. Each recompressor receives a datastream of interleaved pixel data (24, 27; Fig. 5), and predicts and compresses interleaved pixel values (a, c) during each clock cycle, respectively (Fig. 20, 27). One of the recompressors (42) is de-energized in a reduced data processing mode when pixel data is subsampled (36, 38) prior to recompression. Subsampled data is re-ordered (43) prior to recompression. Multiple parallel decompressors (80, 82, 84) coupled to the frame memory provide pixel data to the motion processing network. A control unit (356, 360, 364, Fig. 23) insures an uninterrupted interleaved data flow to the decompressors by repeating last valid data when source data is interrupted.
摘要:
An MPEG decoder (14, 18, 22) in a high definition television receiver decodes and decompresses MPEG coded data to produce decompressed image pixel blocks, and includes a motion compensation network (90...) coupled to a frame memory (60) to produce finally decoded pixel data for display. The decompressed MPEG data is recompressed by plural parallel recompressors (40, 42) prior to storage in frame memory. Each recompressor receives a datastream of interleaved pixel data (24, 27; Fig. 5), and predicts and compresses interleaved pixel values (a, c) during each clock cycle, respectively (Fig. 20, 27). One of the recompressors (42) is de-energized in a reduced data processing mode when pixel data is subsampled (36, 38) prior to recompression. Subsampled data is re-ordered (43) prior to recompression. Multiple parallel decompressors (80, 82, 84) coupled to the frame memory provide pixel data to the motion processing network. A control unit (356, 360, 364, Fig. 23) insures an uninterrupted interleaved data flow to the decompressors by repeating last valid data when source data is interrupted.
摘要:
A video display control system (30) automatically controls a video display responsive to detection of letterbox format input video signals having varying format display ratios. A detection circuit continuously detects the first and last lines of active video in a video signal. A memory stores scan line numbers corresponding to the first and last lines of active video. The height of the picture is determined from the scan line numbers of the first and last lines of active video. The picture height is indicative of the format display ratio of the letterbox input. A comparator circuit compares the picture height to a threshold corresponding to the widest expected format display ratio of a letterbox input signal. A control circuit, for example a microprocessor (30), is operable in a first mode of operation for enabling the memory to continuously update the stored scan line numbers unless the picture height exceeds the threshold.
摘要:
Des données de luminance fournies par un signal vidéo sont sélectivement comprimées et décomprimées dans une première voie de signaux comportant une première mémoire de lignes (356). Une deuxième mémoire de lignes (358) traite, dans une voie de signaux parallèle, les données de chrominance vidéo fournies par le signal vidéo. Un circuit de commande (320) génère des signaux de synchronisation respectifs pour l'enregistrment des données dans les mémoires de lignes et pour la lecture des données à partir des mémoires de ligne. Un circuit de temporisation (337) pour le dispositif de commande peut fonctionner en mode compression vidéo ou en mode décompression vidéo. En mode compression, la lecture de la deuxième mémoire de lignes est différée par rapport à l'enregristrement de la deuxième mémoire de lignes. En mode décompression, l'enregistrement de la première mémoire de lignes est différé par rapport à l'enregistrement de la deuxième mémoire de lignes ou la lecture de la deuxième mémoire de lignes est différée par rapport à l'enregistrement de la deuxième mémoire de lignes. La durée des temporisations peut être sélectionnée à partir d'une plage de valeurs. Les mémoires de lignes sont des dispositifs premier entré-premier sorti comportant des portes de lecture ou d'enregistrement actionnées indépendamment.
摘要:
Compression and decompression apparatus and methods for producing fixed-length compressed data blocks with variable-length compression are described. The compression system receives and N-bit word from a data block (60) and determines the variable compression length for the word (62). A bit counter keeps track of the number of bits remaining (64) and determines if sufficient bits have been used to ensure that the fixed-length compressed data block will be filled (66). If so, the compressed word is output (70). If not, prior to output the compressed word is padded with an appropriate number of bits (68), which may be null bits.
摘要:
An MPEG decoder (14, 18, 22) in a high definition television receiver decodes and decompresses MPEG coded data to produce decompressed image pixel blocks, and includes a motion compensation network (90, ...) coupled to a frame memory (60) to produce finally decoded pixel data for display. The decompressed MPEG data is recompressed by plural parallel recompressors (40, 42) prior to storage in frame memory. Each recompressor receives a datastream of interleaved pixel data (24, 27; Fig. 5), and predicts and compresses interleaved pixel values (a, c) during each clock cycle, respectively (Fig. 20, 27). One of the recompressors (42) is de-energized in a reduced data processing mode when pixel data is subsampled (36, 38) prior to recompression. Subsampled data is re-ordered (43) prior to recompression. Multiple parallel decompressors (80, 82, 84) coupled to the frame memory provide pixel data to the motion processing network. A control unit (356, 360, 364, Fig. 23) insures an uninterrupted interleaved data flow to the decompressors by repeating last valid data when source data is interrupted.