U.S. Philips Corporation

U.S. Phillips Corporation

Stephanus J Nijssen

Peter H De With

Robert Albertus Brondijk

Wilhelmus H Bruls

Franciscus H Bergen

Jan J Rotte

Albert M Rijckaert

Gerrit J Keesman

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

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 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

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

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

Stephanus J Nijssen