Mitsubishi Denki Kabushiki Kaisha

Mitsubushi Denki Kabushiki Kaisha

Mitsubishi Denki Kabsuhiki Kaisha

Junko Ishimoto

Sadayuki Inoue

Ken Onishi

Tomohiro Ueda

Taketoshi Hibi

Tohru Inoue

Masako Asamura

Makoto Kumano

Nobuyoshi Okumura

Satoshi Kurahashi

Tatsuo Yamasaki

Haruhisa Inoue

Takahiko Nakamura

Ikuo Ohkuma

Data separating means extracts intra-frame or intra-field encoded blocks from an intra-frame or intra-field encoded, and inter-frame or inter-field encoded digital video signal, and a digital audio signal contained in an input bit stream. Error correction code appending means appends error correction codes to the extracted intra-encoded blocks. Recording means records the data having the error correction code appended, in special replay data recording areas predefined on the magnetic recording tape. During fast replay or slow replay, error correction is achieved even for the replay signal with a low output level and a poor symbol rate.

Device for recording digital video and audio signals in designated areas of a recording medium in a predetermined track format

In a digital VTR having a certain recording bit rate, within a range not higher than a remaining data rate after recording the bit stream, first HP data Dis recorded in first specific regions, and second HP data Dis recorded in second specific regions in specific tracks. In middle-speed and high-speed fast replay, the magnetic tape is transported continuously at a middle-speed or high-speed higher than the standard speed for normal replay, and the first HP data Dis used in common, and at a low-speed fast replay of about twice the normal speed, the speed of the magnetic tape is alternated between a speed near the standard speed for normal replay, and a speed near the low-speed fast, and at the speed near the standard speed, the second HP data disposed in the second specific regions in the specific tracks and the first HP data disposed in the first specific regions in the specific tracks are both replayed.

Digital VTR

A digital VTR for magnetically recording and replaying a bit stream, includes a detector, an extractor, a mode designator, and an output unit. The detector detects intra-picture data in the bit stream being replayed from tracks in a magnetic medium. The extractor extracts the intra-picture data from the bit stream based on output from the detector. The mode designator designates one of a normal replay and a slow replay as a replay mode. The slow replay is replay performed at a speed slower than normal replay. The output unit stores the extracted intra-picture data, and outputs only the extracted intra-picture data as replay picture data when the slow replay mode is designated.

Digital VTR for recording and replaying data depending on replay modes

Data seperating means extracts intra-frame or intra-field encoded blocks from an intra-frame or inter-field encoded digital encoded, and inter-frame or inter-field encoded digital video signal, and a digital audio signal contained in an input bit stream. Error correction code appending means appends error correction codes to the extracted intra-encoded blocks. Recording means records the data having the error correction code appended, in special replay data recording areas predefined on the magnetic recording tape. During fast replay or slow replay, error correction is achieved even for tile replay signal with a low output level and a poor symbol rate.

Digital VTR for recording special replay video data in track areas

Digital VTR for processing intra-picture data according to replay modes

The digital VTR includes an extractor, variable-length decoder, quantizer and variable-length encoder. The extractor receives digital data divided into blocks, and which is quantized and variable-length coded on a block-by-block basis. Portions of the digital data are encoded according to a first type of encodation, and other portions of the digital data are encoded according to a second type of encodation. The extractor identifies and extracts the digital data encoded according to the first type of encodation. The variable-length decoder variable-length decodes the extracted portions of the digital data, while the quantizer quantizes the decoded data output by the variable length decoder. The variable length encoder variable-length encodes the quantized decoded data to form special-playback data. Alternatively, a convertor converts the extracted portions of the digital data into variable-length coded data having different quantization steps to form the special-playback data.

Digital VTR increasing recorded amount of high priority data

A data separating device extracts intra-frame or intra-field encoded blocks from an intra-frame or intra-field encoded, and inter-frame or inter-field encoded digital video signal, and a digital audio signal contained in an input bit stream. An error correction code appending device appends error correction codes to the extracted intra-encoded blocks. A recording device records the data having the error correction code appended, in special replay data recording areas predefined on the magnetic recording tape. During fast replay or slow replay, error correction is achieved even for the replay signal with a low output level and a poor symbol rate.

A magnetic recording and reproduction apparatus wherein the drum motor is controlled so that the rotation number of the drum during playback at the normal speed multiplied by N (N is an integer) changes by a fixed factor to R(1+q/Q) (Q, q are integers satisfying .vertline.q.vertline.&lt;.vertline.Q.vertline.), assuming the rotation number of the drum during normal playback as R rpm. Also a magnetic recording and reproduction apparatus wherein the drum motor is controlled so that the average rotation number of the drum during playback at the normal speed multiplied by N (N is an integer) becomes approximately R rpm by changing the rotation number of the drum periodically and combining a rotation number of R rpm or less and a rotation number of R rpm or more, assuming the rotation number of the drum during normal playback as R rpm.

Magnetic recording and reproduction apparatus for preventing fixed

A high-efficiency encoding apparatus having a data division circuit which applies 1-dimensional scanning to the orthogonal-transformed data obtained by applying orthogonal transformation to blocked digital data in the unit of block and divides the data into run-length data and coefficient data, an encoding circuit which applies run-length encoding to the divided run-length data by employing data of the highest probability of occurrence (for example 0), and an encoding circuit which applies run-length encoding to the divided coefficient data by employing data of the highest probability of occurrence (for example 1), thereby reduces the amount of the digital data.

High-efficiency encoding apparatus and high-efficiency decoding apparatus

In a magnetic recording/playback apparatus for recording and playing back a digital video signal on a helical track of a magnetic tape using two or more rotary heads, the playback image at the time of high-speed playback is improved by setting the tape travel speed at the time of high-speed playback at an even multiple of a normal playback speed. Further, a tracking phase is offset by one half the track pitch with respect to the tracking during normal speed playback. Alternatively, essential information of the information having been high-efficiency coded is recorded in the central part, and near the ends of the tracks, while high-precision information is recorded in intermediate parts intermediate between the central part and the parts near the ends. Still alternatively, the video data of one of the consecutive fields is recorded in the central part of the tracks and the video data of the other of the consecutive fields is recorded near the ends of the tracks.

Recording/playback apparatus for dividing encoded digital video data

Digital VTR for recording special replay data with appended error

A digital video signal recording and reproducing apparatus which obtains a favorable reproduced picture even when the data overwritten by edited data is interpolated with the data of the preceding field or preceding frame by recording the video data of the visually inconspicuous peripheral area on a track that is possibly overwritten by the editing data at a cut-in point or cut-out point in assemble editing or insert editing. The apparatus further obtains a natural picture without any fixed error even in speed search mode by exchanging the recording order of the video data of one field on plural tracks according to the head scanning trace in the speed search.

Digital video signal recording and reproducing apparatus

In an error-correcting apparatus for correcting errors included in reproduced data which are stored in a RAM, a syndrome generation circuit, a polynomial calculation circuit for calculating an error position polynomial and an error value polynomial, and a position calculation circuit for calculating an error position are operated in parallel. A divider section of the error-correcting apparatus has a divider for performing the division of highest-degree coefficients of two polynomials, a multiplier for multiplying the coefficient of the polynomial set in the divisor side of the divider by the output of the divider, and an adder for adding the output of the multiplier and the coefficient of the polynomial set in the dividend side of the divider. The divider section executes the division over a Galois field while sequentially shifting the contents of registers which store the coefficient data of the dividend polynomial.

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Nagaokakyo, Japan

Junko Ishimoto