Matsushita Electric Industrial Co., Ltd.

Nissan Motor Company Limited

Toyohiko Matsuta

Masaaki Kobayashi

Masafumi Shimotashiro

Masakazu Nishino

Hiroaki Shimazaki

Shigeru Awamoto

Etsuto Nakatsu

Tatsuro Juri

Yuji Fujiwara

Takashi Yamaguchi

Tokikazu Matsumoto

Chojuro Yamamitsu

Ryuji Matsuura

A receiver to receive a mixture of progressive and interlace video broadcast signals without being conscious of switching between the broadcasting systems. The receiver receives the mixed video broadcast signals having different formats, converts received video signals to video signals having a different signal format from the signal format of the received video signals. The receiver simultaneously outputs the received video signals and the converted video signals. This allows the user to be unaware of any switching when the video input changes between the different broadcasting systems, by connecting a television set to either the interlace scanning system output or the progressive scanning system output of the receiver.

Receiver

In the video signal recording apparatus of the present invention, when recording video signals of a plurality of frames after highly efficiently coding the same, video signals of the first frame are coded within the frame and divided into compression blocks each of which block is recorded to a corresponding recording block at a fixed position.

Video signal recorder having a frame coder

When a standard TV signal of digital format is a first video signal and another digitized TV signal having a bandwidth wider than that of the first video signal is a second video signal, every two frames of the second video signal are calculated to produce a pixel value sum of the two frames and a pixel value difference between the same and either a resultant interframe calculated output or the first video signal is compressed through two-dimensional orthogonal transformation for ease of storage.

Video signals recorder and player including interframe calculating means

An encoding and decoding apparatus for a video signal and a high-definition television signal is disclosed. For the picture A having the horizontal to vertical screen frame ratio of 4:3, the picture B having the horizontal to vertical screen frame ratio of 16:9 and the picture C having the horizontal to vertical screen frame ratio of 16:9 and having a larger number of vertical pixels than that of the picture A and picture B, the apparatus limits the band of the picture C to obtain the picture D having the same numbers of horizontal and vertical pixels respectively as those of the picture B, and high-efficiency encodes the picture A, picture B or picture D in the same method. The apparatus obtains the additional picture E which is a difference between the picture D and the picture C, or a difference between the picture D' which is a result of decoding a signal that has been obtained by high-efficiency encoding the picture D and the picture C, and then high-efficiency encodes the additional picture E obtained.

Video signal encoding and decoding apparatus

In digital video signals which differ in the number of pixels thereof, such as a standard video signal having a screen aspect ratio of 4:3 and a wide video signal having an aspect ratio of 16:9 the data quantity after encoding is equalized without increasing the compression ratio of the video signal having the larger number of pixels. An encoding apparatus performs intraframe encoding of the standard video signal so that the coded data quantity is constant in every frame, and interframe encoding of the wide video signal in each two frames so that the coded data quantity is constant in every two frames.

Standard screen image and wide screen image selective receiving and

An input video signal is converted into a digital signal by a clock of a predetermined time interval. Of the time base errors included in the above signal, time base errors of the clock unit are corrected by resetting the write address of the memory, and time base errors of less than the clock unit and velocity errors are corrected by an interpolation filter provided at a later stage of the memory. By the above processing, it is possible to correct time base errors by only a clock of a predetermined interval and it is also possible to improve interface characteristics with other digital processing sections.

Time base corrector

A digital signal magnetic recording and playback apparatus which is applicable to digital video signals, utilizes quadrature amplitude modulation to produce a recording signal from a digital input signal with a carrier frequency being employed which is less than or equal to than the frequency of a recording system clock signal that is synchronized with the successive data values of the digital input signal. Carrier bursts are periodically inserted into the recording signal with a fixed period, through data inserted by a burst data insertion circuit and the carrier and clock signal are arranged to periodically coincide in phase, with the aforementioned period. The carrier frequency is made equal to the clock frequency multiplied by a factor (n/m), where n and m are integers and n&lt;m. During playback, time information obtained from the bursts is used to mutually phase-relate recovered clock and carrier signals.

Digital signal magnetic recording and playback apparatus employing

A digital signal magnetic recording/reproducing apparatus modulates a digital signal with a carrier and performs recording/reproducing of the modulated signal. The carrier frequency is made equal to the clock frequency multiplied by a factor (N/M), where N and M are integers. The carrier and clock are reproduced using only one phase locked loop. When the carrier-modulated signal is recorded/reproduced using a magnetic recording medium, the phase of the modulated signal is shifted relative to the phase of the carrier. Shifting the clock phase before using the clock for decoding the demodulated signal prevents a degradation of error rate. By periodically inserting a clock phase reference signal in the recording signal, accuracy of adjustment of clock phase is improved.

Digital signal magnetic recording/reproducing apparatus

A digital signal magnetic recording/reproducing apparatus converts a digital signal into multi-value digital signals and performs recording/reproducing of a multi-value quadrature amplitude-modulated signal. By using the multi-value quadrature amplitude modulation, it is possible to remove the DC component in the recording signal and improve the utilization efficiency of the recording frequency band. Further, using a system to memorize the frequency characteristic of the magnetic recording/reproducing unit and effect Viterbi decoding regarding the intersymbol interference caused by the frequency as a convolutional coding, it is possible to detect the level without necessitating frequency equalization. Accordingly, there arises no deterioration of the S/N ratio by frequency equalization. Furthermore, by providing an encoder for error control coding by increasing the number of multi-values and a corresponding decoder, the error rate can be improved against the deterioration of the S/N ratio. Further, by bias recording the multi-value quadrature amplitude modulated signal, non-linearity of the electromagnetic conversion system is relaxed, and deterioration of the S/N ratio by distortion is improved.

Digital signal magnetic recording/reproducing apparatus using

A digital signal magnetic recording/reproducing apparatus converts a digital signal into a multi-value digital signal, followed by recording/reproducing the quadrature biphase modulated multi-value quadrature amplitude modulated signal. By using a multi-value quadrature amplitude modulation, a direct current component in the recorded signal can be eliminated, and the utilization efficiency of the recording frequency band of the digital signal magnetic recording/reproducing apparatus can be improved. Also, with respect to the amplitude non-linear characteristic which occurs in the magnetic recording/reproducing process, by providing a compensating circuit during the mapping before recording or after reproducing and demodulating, the deterioration of the S/N ratio of the reproduced and demodulated signal can be reduced to decrease the errors in the decoded data. Furthermore by bias-recording the multi-value quadrature amplitude modulation signal, the non-linearity of the electromagnetic conversion system is alleviated to decrease the deterioration of the S/N ratio due to distortion, thereby making the application of the modulation scheme more reliable.

A digital signal magnetic recording/reproducing apparatus converts a digital signal into a multi-value quadrature amplitude modulated signal, and records and reproduces the multi-value quadrature amplitude modulated signal. By using the multi-value quadrture amplitude modulation, any DC component in the recording signal is removed and utilization efficiency of the recording frequency band can be improved. By bias recording of the multi-value quadrature amplitude modulated signal, non-linearity of the electromagnetic of conversion system is reduced, and deterioration of SN ratio due to distortion is improved.

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Katano, Japan

Toyohiko Matsuta