U.S. Philips Corporation

U.S. Phillips Corporation

Peter H De With

Stephanus J Nijssen

Wilhelmus Jacobus Van Gestel

Robert Albertus Brondijk

Albert M Rijckaert

Wilhelmus H Bruls

Franciscus H Bergen

Stephanus M Borgers

Roeland Den Bakker

Jan J Rotte

Marcel Breeuwer

Gerrit J Keesman

Eric H Persoon

Peter H Frencken

Alphonsius A De Lange

Egidius A Habraken

Roeland Pieter De Bruijne

Petrus D Verlinden

A method and apparatus wherein video images are recorded on a plurality of tracks of a tape such that, for playback in a search mode at a speed, higher than the recording speed the displayed image will consist of a plurality of contiguous parts, some of the parts being read out from tracks each having a different frame recorded thereon.

System and method for improving video recorder performance in a search

Method and device for decoding coded digital video signals

A method and apparatus wherein video images are recorded on a plurality of tracks of a tape such that, for playback in a search mode at a speed higher than the recording speed, the displayed image will consist of a plurality of contiguous parts, some of the parts being read out from tracks each having a different frame recorded thereon.

To be able to transmit television pictures in a digital form through a medium having a limited bandwidth, the pictures are subjected to picture transform and to variable-length coding. The picture to be transmitted is converted in this manner into a bit stream comprising code words of variable length. This bit stream is converted into a channel bit stream which is less sensitive to transmission errors. To this end the most significant code words (representing the average luminance and the coarse picture details) of sub-pictures of 8*8 pixels are accommodated at fixed bit positions of the channel bit stream. These code words can be retrieved by simple count-down of the bit positions. The other code words are distributed over the other bit positions. The decoder is relatively simple because the length of each block comprising significant code words is also transmitted. This length is preferably adapted to the extent of picture detail in the sub-picture.

Television system for transmitting pictures in a digital form

A multimedia system has unprogrammable task-specific processors of high performance-density. The task-specific processors perform primitive functions that together constitute a video algorithm. The task-specific processors are interconnected via a high-speed communication module whose interconnectivity is controlled by an arbiter. The arbiter stores a data flow graph. A fully programmable general-purpose processor of low performance-density carries out those tasks that are not readily mapped onto the primitive functions. This configuration with different levels of performance-density and programmability increases overall system performance-density with regard to the prior art.

Multi-media processor architecture with high performance-density

A converter with which an extended definition (ED) video signal may be converted into a signal that may be recorded by a video recorder and with which a signal read out by a video reorder may be converted to an ED video signal. The ED video signal includes first lines having a first luminance signal (Y.sub.1) and a chrominance signal (C), and second lines having no chrominance signal but a second luminance signal (Y.sub.2) in the form of a modulated luminance signal with suppressed carrier. The converter includes a separation unit which receives the ED video signal from an input terminal and has three outputs. A first output couples the first luminance signal to a first output terminal via a first signal combination unit. A second output couples the chrominance signal to a second output terminal via a second combination unit. The third output is coupled to the first output terminal via a mixer circuit and the first combination unit.

Extended definition video signal converter for use with a video recorder

Video images are encoded by transform coding, resulting in data blocks each including a DC-coefficient and a plurality of AC-coefficients. The coefficients of a number of said transform blocks are variable-length encoded and transmitted. In order to avoid a complete loss of datablocks in case of a transmission error, the most significant codewords of a group of blocks are transmitted first so as to achieve that at least the DC-level of the blocks is likely to be retained. The coefficients may also be recorded on a videorecorder. Fast playback of recorded images so encoded, leads to very poor quality because some data blocks are not being read in the search mode. To improve this quality the DC-coefficients and if desired predetermined AC-coefficients of selected ones of the transform blocks to be recorded on one track are packed together to form a DC-packet and such packet is recorded on a selected part of the track. The DC-packet is chosen such that it can be read out as a unit at various search speeds, and can be read partially at higher search speeds.

Method of and system for transmitting and receiving digitally encoded

Device for transmitting or storing digital television pictures in which a maximum possible number of data of a group of transformed pixel blocks (DB.sub.1 . . . DB.sub.12) is transmitted in the form of variable-length code words (V.sub.1 . . . V.sub.N) in a corresponding channel block of predetermined length (FIG. 5A). If all code words of the groups of blocks are accommodated in the corresponding channel block (FIG. 5C), the channel block will also comprise surplus data of other blocks. The boundary, within a channel block, between these code words and surplus data is transmitted in the form of an address (P) which is accommodated at a predetermined position of the channel block. If the channel block length is inadequate for transmitting all code words of the group of blocks, the channel block (FIG. 5B), will comprise at least the code words which are representative of the DC coefficient and a number of important AC coefficients of each block. Said code words are accommodated in successive channel block sections (L.sub.1 . . . L.sub.12), with a code (C) for the length of these channel block sections being transmitted at predetermined positions of the channel block.

Device for transmitting or storing digital television pictures, and

Video encoder and decoder, provided with a motion compensator for motion-compensated video coding or decoding in which a picture is coded or decoded in blocks in alternately horizontal and vertical steps. The motion compensator is provided with addressing means (160) and controlled multiplexers (111-119) for refreshing a search area memory (101-109) at each step, in conformity with the direction of the step.

Video encoder/decoder for encoding/decoding motion compensated images

Arrangements for recording and reproducing datareduced videoinformation are described. The recording arrangement comprises a datareduction unit (3) and a formatting unit (4). The formatting unit (4) generates packets (P.sub.i) each having a first, second and third packet portion (PP.sub.1, PP.sub.2 and PP.sub.3). The first packet portion comprises a sync word (SW) and an identification word. The second packet portion comprises datareduced videoinformation of a first and a second datablock (MB.sub.0, MB.sub.1). A datablock comprises DC coefficients (DC.sub.i) and most significant and least significant AC coefficients (MAC.sub.i, LAC.sub.i). The videoinformation comprised in the first and the second datablock are stored in the second packet portion (PP.sub.2), such that the DC coefficients of the first datablock (DC.sub.0) are stored first, the plurality of most significant AC coefficients (MAC.sub.0) of the first datablock are stored next, the DC coefficients of the second datablock (DC.sub.1) are stored last in the second packet portion, and the plurality of most significant AC coefficients (MAC.sub.1) of the second datablock are stored before the DC coefficients of the second datablock in the second packet portion. This enables an improved reproduction of the videosignal in a feature mode.

Arrangement for recording or reproducing data reduced video information

A motion detector, particularly for use in a television system for transmitting television pictures in a digital form, is adapted to partition each picture into pixel blocks, to subject each pixel block to a modified intraframe transform for determining a first coefficient which corresponds to the basic picture having the lowest horizontal and highest vertical frequency, and to determine a plurality of further coefficients which correspond to basic pictures also having the lowest horizontal frequency, but a vertical frequency which is lower than that for the first coefficient. The motion detector signalizes the presence of motion within a pixel block if the first coefficient has a large absolute value, but if simultaneously none of the further coefficients has a sufficiently large absolute value. If the first coefficient has a sufficiently large absolute value, absence of motion is nevertheless signalized if simultaneously one of the further coefficients also has a sufficiently large absolute value.

Television system for transmitting digitized television pictures from a

A system for recording and reproducing an extended definition (ED) video signal in/from a track on a magnetic record carrier wherein an ED video signal, such as a PAL-PLUS video signal, includes first lines having a first luminance signal (Y.sub.1) and a chrominance signal (C), and second lines having no chrominance signal but a second luminance signal (Y.sub.2) in the form of a modulated luminance signal with suppressed carrier. The recording device includes a first signal path (11,31,32,16) for processing the first luminance signal, a second signal path (11,18) for processing the chrominance signal and a third signal path (10,30,32,16) for processing the second luminance signal prior to the three signals being combined (22) and recorded on the record carrier. The reproducing device also includes a first (48,50) a second (52,53) and a third signal path (48,73,83) for processing the first luminance signal, the chrominance signal, and the second luminance signal, respectively. Furthermore, a converter is described with which an ED video signal may be converted to a signal that may be recorded by a video recorder and with which a signal read out by a video recorder may be converted to an ED video signal.

System and apparatus for recording and reproducing and extended

A coded data stream with end-of-block (EOB) words is divided into groups each having n EOB words so that loss of an EOB word can be determined at the receiver. When such loss is determined, EOB word(s) is or are inserted locally at the receiver to prevent shift of correctly decoded blocks relative to their true position in the image to be reconstructed.

Video coder/decoder with shift prevision for correctly decoded signal

To be able to transmit television pictures in a digital format on a medium having a limited bandwidth, the picture are subjected to a coding operation and thereby converted into a series of transmission bit blocks TRB.sub.n of variable length (for example DCT and variable length coding). Each transmission bit block is divided into a main block H.sub.n having at least the most important code words and an auxiliary block S.sub.n comprising the other code words. By carrying out a formatting operation, a group of transmission bit blocks is converted into a channel bit block consisting of a number of sub-channel bit blocks SCB.sub.n of equal length. The main blocks are accommodated at the first bit positions of the sub-channel bit blocks and the bits of the auxiliary blocks are spread over the remaining bit positions. It is thereby achieved that the most important information is always found at fixed locations so that the influence of sync losses is reduced considerably.

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Eindhoven, Netherlands

Peter H De With