Victor Company of Japan, Limited

Tomoyuki Shindo

Takeo Ohishi

Yutaka Tanaka

Tsuyoshi Suzuki

Yasuaki Yamada

Tetsuya Suwa

Seiji Higurashi

Jin Ogasawara

Activities of a video signal are obtained for subblocks of each macroblock of each picture. The smallest activity is detected as an input-picture activity per macroblock. Obtained are activities of a motion-compensated predictive signal per first picture and activites of the video signal per second picture, for the subblocks of each macroblock. A mean value of the activities is obtained per macroblock for each picture, as an error activity per macroblock. A mean error activity is obtained for error activities per picture. A quantization step size for quantization of the video signal is adjusted per macroblock, according to the input-picture activity, to obtain a smaller step size when the error activity is equal to or larger than the mean error activity than when the former is smaller than the latter.

Adaptive quantizer, adaptive quantization method and adaptive quantization program

A signal related to input moving pictures of plural different types is quantized in response to a variable quantization scale factor before being encoded. An actual complexity of each past encoded picture originating from one of the input moving pictures is calculated. A complexity of a next encoded picture is estimated in response to the actual complexity of a past encoded picture same in type as the next encoded picture in cases where the next encoded picture does not correspond to a scene change. A complexity of the next encoded picture is estimated in response to the actual complexity of a past encoded picture different in type from the next encoded picture in cases where the next encoded picture corresponds to a scene change. A value of the quantization scale factor used for the quantization is decided in response to the estimated complexity.

Method and apparatus for encoding a moving-picture signal by calculating the complexity of the moving-picture signal

First information is divided into equal-size information pieces. Serial numbers are assigned to the information pieces, respectively. An encryption key is generated from a base number and a variable number varying for each of the information pieces. The base number is common to an information range managed by one licence. The first information is encrypted on a block-by-block basis in response to the encryption key to get encryption-resultant information for every predetermined minimum information unit smaller than the sizes of the information pieces. The encryption-resultant information is recorded on a recording medium. A determination is made as to logical addresses of heads of portions of the recording medium which are loaded with portions of the encryption-resultant information corresponding to the respective information pieces. Second information representing a correspondence relation between the determined logical addresses and the assigned serial numbers is recorded on the recording medium.

Information recording apparatus having function of encrypting information

A packet recording/reproducing system is provided which records or reproduces packets on or from tracks formed in time sequence on a magnetic tape. In a recording operation, the packet recording/reproducing system adds to input packets time stamps whose values are synchronous with packet arrival time control clocks produced by the system. The timing with which the packets are recorded on the magnetic tape is controlled by the arrival time control clocks so that a given number of the packets inputted at high data rate are recorded within a one-track area, a two-track area, or a one-track over area defined across at least two of the tracks, thereby minimizing the loss of capacity of the magnetic tape.

Packet data recording/reproducing system

Data is received which is transmitted through a serial bus in a predetermined transmission band. The serial bus is preferably in conformity with the IEEE 1394 standards. One of recording modes for different recording rates is selected in accordance with the transmission band of the received data. The data is recorded in the selected recording mode. Data is reproduced which has been recorded in a recording mode for a predetermined recording rate. A transmission band is allocated, based on the recording mode, for transmitting the data through a serial bus.

Apparatus and method of data processing through serial bus

Packet data system recording time stamps and packet data on tracks

A digital TV broadcasting signal is demodulated to obtain a bit stream containing at least a first packet of a first program specific information concerning all TV programs conveyed by the digital TV broadcasting signal and first packets of the TV programs themselves. Selection data is entered for selecting at least one of the TV programs. In response to the selection data, only second packets are selected from among the first packets. The second packets contain only data of the selected TV program. The second packets are decoded. Further, the first packet and the second packets are output without decoding and accepted. The first program specific information is modified into a second program specific information concerning the selected at least one of the TV programs. The modification is executed after the first packet and the second packets are output. Or, the modification is executed before the first packet and the second packets are accepted.

Apparatus and method of receiving broadcasted digital signal

A drum servo system is provided with a rotation control device for controlling the rotation of a drum on the basis of a phase comparison signal obtained as a result of comparing the phase of an angle-of-rotation information signal obtained according to an angle of rotation of the drum with the phase of a control signal. The system also includes a detection device for determining the existence of a large data block or a small path block and outputting the result to a reference signal generator. The frequency of the reference signal is higher than that of the control signal, and is altered based on the output of the detection device. Frequency division is performed on the reference signal after it has been acted on by a phase locked loop, and the result is compared to the phase of the angle-of-rotation information signal in the rotation control device. Thus, a radical change in the control signal which occurs when the phase or frequency of the control signal is changed due to an abrupt external disturbance can preferably be absorbed in the comparison control device. Thereby, the rotation control device can always stably follow an abrupt change occurring in the control signal.

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Yamato, Japan

Tomoyuki Shindo