Abstract: Unauthorized copying of a digital video program is prevented by designating a first block and a second block of data in a bit stream encoded by a fixed length code. A portion of the first block is selected as key data and inserted into the second block to indicate that the digital video program is a copy and to prevent illegal copying.

Abstract: A picture signal encoding method in which a picture string produced by converting non-interlaced pictures into sets of field pictures each beginning from the first field of each interlaced picture and another picture string produced by converting non-interlaced pictures into sets of field pictures each beginning from the second field of each interlaced picture are combined together to an input picture signal for encoding, is disclosed. The method includes a detection step of detecting a lone field not constituting the non-interlaced picture in the input picture signal, and an encoding step of re-constructing the picture string of the input picture signal and encoding the resulting non-interlaced picture string.

Abstract: In multiplexing a plurality of coded data, degrees of difficulty of coding of the data are measured, coding rate for each of the data is decided by allotting a certain target bit rate with a ratio of the each of the measured degrees of difficulty of coding so that the bit rate of the multiplexed data becomes equal to the target bit rate, the data is then coded in response to the decided coding rates, and the coded data is multiplexed before being outputted to a transmission line or recording medium. Thus, the bit rate of the outputted data is always kept at the target value to improve the usage rate of a transmission line.

Abstract: A method for encoding a digital signal which is free from overflow and/or underflow of decoder buffer when video and audio data are reproduced while switching a plurality of bit streams from one to another, is disclosed.

Abstract: A method and an apparatus for satisfactorily reproducing an image and voice even if skip reproduction is performed, the apparatus having a first decoding system for decoding coded data of each picture more forward than a skip start point, a second decoding system for decoding coded data of each picture following a skip end point and a switch which corresponds to skip reproduction so as to switch a data string decoded by the first decoding system to a data string decoded by the second decoding system. The second decoding system completes decoding of all of pictures required to decode pictures following the skip end point prior to completion of decoding pictures more forward than the skip start point by the first decoding system. When the first decoding system has decoded the pictures more forward than the skip start point, the second decoding system outputs decoded data of each picture following the skip end point.

Abstract: A picture signal encoding method in which a picture string produced by converting non-interlaced pictures into sets of field pictures each beginning from the first field of each interlaced picture and another picture string produced by converting non-interlaced pictures into sets of field pictures each beginning from the second field of each interlaced picture are combined together to an input picture signal for encoding, is disclosed. The method includes a detection step of detecting a lone field not constituting the non-interlaced picture in the input picture signal, and an encoding step of re-constructing the picture string of the input picture signal and encoding the resulting non-interlaced picture string.

Abstract: Apparatus and method for coding a moving picture signal and decoding a coded moving picture signal. The input picture signal of higher resolution is down-sampled at respective ratios in the longitudinal and lateral directions to generate a picture signal of lower resolution having a different aspect ratio. The coded picture signal of lower resolution is up-sampled at respective ratios in the longitudinal and lateral directions to generate a picture signal of higher resolution having a different aspect ratio.

Abstract: A video signal transmission method and apparatus for instantaneously providing a normally reproduced picture upon start of an image data transmission or in other potentially unstable states through steady processing, wherein the image signal of one frame is first divided into a plurality of blocks. The image signal of the divided blocks is coded by intraframe coding and interframe coding. The intraframe-coded signal for one frame is transmitted periodically. Meanwhile, the magnitude of the correlation between two blocks is detected, one of the two blocks belonging to a given frame and corresponding to the other block belonging to the preceding frame. Then the quantization characteristic of the image signal to be transmitted is controlled in accordance with the detected magnitude of the correlation.

Abstract: A picture series is encoded so that a first type of decoder having only one frame memory and incapable of bi-directional decoding can decode the encoded bitstream, and a second type of decoder having multiple frame memories and capable of bi-directional decoding can decode the encoded bitstream to produce a higher quality decoded picture series. The encoded bitstream comprises three parallel channels of encoded picture data. The first channel includes every other picture and header information common to the second and third channels. The second channel includes the pictures not represented in the first channel and encoded by one of forward and backward predictive coding. The third channel includes the pictures not represented in the first channel and encoded by bi-directional predictive coding. The first type of decoder uses the first and second channels, while the second type of decoder uses the first and third channels.

Abstract: A method and apparatus for encoding moving picture signals. A plurality of encoding picture groups, each consisting of a pre-set number of encoding pictures freed of redundant pictures from a plurality of original pictures represented by the input moving picture signals, are formed, and the number of original pictures used for forming the encoding picture groups and the group-based target bit amount are calculated. The moving picture signals of the encoding pictures are encoded from one picture group to another based upon the target bit amount. Even if the encoding picture rate is changed from one picture group to another, the target bit amount can be adaptively controlled with these changes in the encoding picture rate. Consequently, there is no risk of the output bit rate significantly surpassing the target value.

Abstract: A picture type identifier, indicating one of intra-picture coding (an I-picture), forward or backward predictive coding (a P-picture) and bi-directionally predictive coding (a B-picture), is included with a picture signal when the signal is encoded and when the signal is decoded. Each of initial and subsequent encoding and decoding is a function of the included picture type.

Abstract: A formatting apparatus authenticates an information signal prior to mass duplication of the signal by analyzing the signal to detect the presence or absence of a security signal therein, inserting a security signal into the information signal, and recording the modified signal only if no security signal was detected.

Abstract: Recording unit is operative so that, in the case of carrying out high speed reproduction, switch is switched by high speed reproduction control signal inputted from the external, and a signal read out from the recording unit is inputted to VLD and formatter. High speed reproduction control signal is inputted to recording unit, switch and counter. Recording unit reproduces and outputs predetermined data in accordance with high speed reproduction control signal. At VLD, variable length encoding of MPEG is released, and syntax analysis is carried out. Counter counts the number of frames to be transmitted. Moreover, counter outputs temporal.sub.-- reference in accordance with reproduction speed indicated by high speed reproduction control signal. Header converter rewrites temporal.sub.-- reference in picture header in accordance with temporal.sub.-- reference outputted from counter. From facts as described above, high speed reproduction of moving picture can be made.

Abstract: Image data of four frames are stored in four memories and the image data from the four memories are sequentially transmitted, whereby still picture image data having a resolution twice the resolution of a common intermediate format (CIF) image based on the video CODEC recommendation H.261 can be transmitted.

Abstract: A method and apparatus for encoding moving picture signals. A plurality of encoding picture groups, each consisting of a pre-set number of encoding pictures freed of redundant pictures from a plurality of original pictures represented by the input moving picture signals, are formed, and the number of original pictures used for forming the encoding picture groups and the group-based target bit amount are calculated. The moving picture signals of the encoding pictures are encoded from one picture group to another based upon the target bit amount. Even if the encoding picture rate is changed from one picture group to another, the target bit amount can be adaptively controlled with these changes in the encoding picture rate. Consequently, there is no risk of the output bit rate significantly surpassing the target value.

Abstract: An encoding and decoding apparatus and method which has the primary benefit over the prior art of not requiring storage of the nonlinear sequence of numbers representative of the quantization characteristics. The hardware required for quantization is reduced and inverse quantization may be achieved using shifting operations and a multiplier of up to half the scale compared to conventional encoding/decoding methods and encoding/decoding apparatus.

Abstract: Picture signals are encoded so that one of a frame-based orthogonal transformation or a field-based orthogonal transformation is selected as a function of frame-based orthogonal-transformation coefficients and field-based orthogonal transformation coefficients. The coefficients representing the smallest quantity of data are selected and encoded for transmission. Alternatively, a picture signal is encoded so that one of intra-frame coding and inter-frame coding, as well as either a frame-based or field-based orthogonal transformation, are selected as a function of the respective orthogonal transformation coefficients.

Abstract: Only monitor side is caused to have decoding unit portion for bit stream, and reading unit portion for bit stream, decoding unit portion for bit stream and recording unit portion for bit stream are linked by digital network. Reproducing unit is caused to have a function to reproduce bit stream as it is, and recording unit is caused to have a function to record bit stream as it is. Bit stream reproducing unit and bit stream decoding unit of the monitor side, and such reproducing unit and bit stream recording unit are linked by high speed digital network. Thus, in the case where there is constructed a moving picture reproducing system such that a plurality of moving picture reproducing units are connected to one moving picture display unit to utilize source desired to see by selection of switch, cost can be reduced and degradation of the picture quality can be prevented.

Abstract: A motion picture encoding method and apparatus for adaptively switching filters in accordance with the property of a motion picture and the condition for encoding and to improve the encoding efficiency. A motion picture is encoded a plurality of times, an encoding parameter for encoding is optimized, the property of the motion picture signal is measured, and filtering is performed by using the encoding parameter or the property of the measured motion picture signal and thereby optimizing the filter characteristic only for the final-time encoding so as to practically generate and output an encoding signal (bit stream).

Abstract: A coding system for transmitting stereo image data, wherein an image for the left eye is disposed in odd fields and an image for the right eye is disposed in even fields, respectively. Frames F1, F2, F3 and F4 are sequentially coded in an order of I picture, B picture, P picture and B picture. The picture in each frame is coded by adaptively switching between a frame prediction mode or field prediction mode or a frame DCT mode or field DCT mode. Thereby, the parallax can be efficiently coded.