Abstract: The present invention provides a transcoder having a MPEG decoder and a MPEG encoder, for changing a GOP structure and the bit rate of an encoded bitstream obtained as a result of an encoding process. The MPEG encoder receives a past encoding parameters generated at a past encoding process as a history information, and performs a present encoding process by using the past encoding parameters selectively so that the present encoding process is optimized. Furthermore, the encoder describe the past encoding parameters into the encoded bitstream as the history information so as to reuse the history information in advance encoding process. The picture quality of the video data does not deteriorate even if decoding and encoding processes are carried out repeatedly by the transcoder.

Abstract: When editing an image signal and a sound signal or these signals multiplexed using a conventional digital signal editing apparatus, it is necessary to provide a reproduction apparatus for reproducing an original signal and a recording apparatus for recording the signal edited. This significantly increases the size of the editing system. According to the present invention, a read-out unit 2 reads out I pictures, B pictures, P pictures, and a reproduction information on a reproduction interval of this coded data from a storage medium 1 allowing random access. A storage unit 3 stores the reproduction information read out from the storage medium 1 by the read-out unit 2. A control unit 3 controls read-out of the read-out unit 2 according to the aforementioned reproduction information from the storage unit 3.

Abstract: A transmission side of a communication apparatus of the present invention makes use of a clock signal synchronized with a network to transmit an arrival interval of a PCR packet in which a PCR value is included and a synchronization residual. A reception side of the communication apparatus of the present invention calculates delay fluctuations caused by the network from the arrival interval and the synchronization residual included in the received PCR packet and modifies the PCR value based on the delay fluctuations.

Abstract: A video signal compressing method and a video signal compressing apparatus for compressing a video signal for a system in which for a synchronism between a plurality of compressed signals must be maintained. A presentation time stamp and/or a decode time stamp are multiplexed in a stream for transmission in which a video signal is compressed to generate a compressed signal. The following are generated as access unit information (AUI) for use in multiplexing the compressed data of the video signal: a picture size value, a picture type value, a repeat first field value, and a flag indicating the occurrence of a big picture.

Abstract: When editing an image signal and a sound signal or these signals multiplexed using a conventional digital signal editing apparatus, it is necessary to provide a reproduction apparatus for reproducing an original signal and a recording apparatus for recording the signal edited. This significantly increases the size of the editing system.

Abstract: A digital signal multiplexing method and apparatus in which plural degree-one multiplexed streams produced on time-divisionally multiplexing a bitstream of one or more digital signals are received and are time-divisionally multiplexed to generate a degree two multiplexed stream. Specifically, plural degree-one multiplexed streams are received, and the received degree-one multiplexed streams are time-divisionally multiplexed based on a repetitive pattern associated with the bitrate of the respective degree-one multiplexed streams to generate a degree two multiplexed stream. The time reference value attached to the degree two multiplexed stream is corrected based on the reference clocks not synchronized with the system clocks of the degree-one multiplexed streams. A pre-set volume of the dummy data is multiplexed if the corrected time reference value becomes larger than the time reference value attached to the degree-one multiplexed streams.

Abstract: A system for seamlessly splicing two encoded video streams. In one implementation of the system, one or more coding parameters are extracted from the first and/or second encoded streams and one or more parameters of the first and/or second encoded streams are changed in accordance with the extracted parameter(s) in order to effectuate seamless splicing. In another implementation, the coding parameters applied to the first encoded stream are referenced when encoding the second stream such that the resulting second encoded stream can be seamlessly spliced with the first encoded stream.

Abstract: Encoding parameters of picture and higher layers of importance to a number of applications, and encoding parameters of slice and lower layers of no importance to all applications are converted into auxiliary packets inserted respectively into a V-blanking area and an H-blanking area of a video-data signal output by a history-information-multiplexing apparatus employed in a video-decoding system. On the other hand, a video-encoding system extracts back the auxiliary packets superposed on the V-blanking area and the H-blanking area from an input base-band video signal. As a result, a technique of superposing information on data can be changed in accordance with the importance of the information and required information can be fetched with ease.

Abstract: In the speckled broadcasting of HDTV and SDTV, an encoding transmitting apparatus and a decoding receiving apparatus can perform a parallel multichannel transmission and reception of SDTV with a simple construction. When an HDTV video signal is encoded and decoded, each of the transmission buffer 30 and the reception buffer 80 is used as a single buffer. On the other hand, when a plurality of SDTV video signals are encoded and decoded, the transmission buffer 30 and the reception buffer 80 are divided into the number of SDTV video signals to use them as a plurality of divided transmission buffers and a plurality of divided reception buffers, so as to perform a encoding and decoding processing.

Abstract: Synchronous information indicates a difference (&bgr;) between a PCR value E and a counter value N (=3240000), if the third PCR packet is assumed to arrive at a transmitting apparatus 201 at the time (time t1) the count value N becomes 3240000, on the basis of a difference (&agr;) between the PCR value E3 and the count value N3, both generated while as many clocks as (count value N3—reference clock value B) are being counted. Hence, the delay fluctuation generated on a network can be eliminated.

Abstract: An editing apparatus and the like are provided for splicing two data streams of compressed picture data at an arbitrary splice point without breaking down the VBV buffer. The editing apparatus inserts between a main stream and a sub-stream compressed by the MPEG-2/Video Method an inserted stream of which a first picture is a black I picture and succeeding pictures are repeat P pictures of which all macro blocks are skipped macro blocks. In this inserted stream, a VBV delay of a picture to be transmitted next, after a last picture in the main stream, is written as a VBV delay of a first picture in the main stream into the picture header. Further, a stuffing byte of which the data amount is calculated based on the bit occupancy in the VBV buffer by the sub-stream at an arbitrary splice point is transmitted along with the last picture in the inserted stream.

Abstract: A multiplexing apparatus and method, a transmitting apparatus and method, and a recording medium arranged to prevent a delay of one of multiplexing scheduling processing and multiplexing processing in accordance with a schedule obtained by the multiplexing scheduling processing from influencing the other of these processings. A scheduler calculates schedule information on the basis of access unit information from an encoder and stores the calculated schedule information by supplying it to an intermediate buffer. If some additional data is to be multiplexed, the scheduler also calculates the additional data and stores the calculated additional data by supplying it to an intermediate buffer. A bit stream multiplexer reads out schedule information from the schedule information intermediate buffer, selects data designated by the schedule information from an elementary stream from the encoder and from additional data stored in the additional data intermediate buffer, and outputs the data as a multiplexed stream.

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: A method and an apparatus for verifying a multiplexing schedule of digital signals and an apparatus for multiplexing the digital signals are provided. The verifying method includes the processes of extracting access unit information about each decoding unit from each elementary stream of the digital signal, determining schedule information about time division of each elementary stream, based on the access unit information, and verifying whether or not the multiplexing schedule for generating the multiplexed stream is valid, based on the access unit information and the schedule information.

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: Synchronous information indicates a difference (&bgr;) between a PCR value E and a counter value N (= 3240000), if the third PCR packet is assumed to arrive at a transmitting apparatus 201 at the time (time t1) the count value N becomes 3240000, on the basis of a difference (a) between the PCR value E3 and the count value N3, both generated while as many clocks as (count value N3−reference clock value B) are being counted. Hence, the delay fluctuation generated on a network can be eliminated.

Abstract: A multiplexed stream MBa is formed by multiplexing at step S1. In switching to given ones of N multiplexed streams MBb, buffer occupation information in an end portion of MBa is detected at step S2. At step S3, buffer quasi-amounts in a head portion of the given ones of MBb are detected and the given ones of MBb are formed by multiplexing such that the buffer quasi-amounts are not exceeded. At step S4, a locus of the maximum value of the buffer occupation amounts by the N streams MBb in their end portion is detected. At step S5, a multiplexed stream MBc is formed by multiplexing such that the locus of the maximum value of the occupation amounts is not exceeded.

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: A method and apparatus for encoding a digital signal in the form of a stream, which will be decoded later via a predetermined number of buffers, in which the digital signal is encoded by dividing each access unit defined for each bit stream into pseudo access units each having a predetermined size, calculating the time when the inputting of each pseudo access unit to the buffer is completed on the basis of the decoding time of the access unit and the data transfer rate of the buffer, and converting the pseudo access units into a packet so that the pseudo access units will be input to the buffer by the time determined by the calculation. If each access unit for each bit stream has a small size and if the decoding interval between adjacent access units is short, a plurality of the access units are combined into a single pseudo access unit depending on the size of the buffer and the data transfer rate of the buffer. The invention also provides a method and apparatus for transmitting similarly obtained data.

Abstract: A picture encoding method in which the picture signal can be scrambled without deteriorating the picture quality of the encoded picture of the MPEG system. A B-picture f the input picture signal is given random offset in the horizontal direction on the slice basis and encoded by an MPEG encoding device. An offset amount is written as a key on the disc along with the encoded data. A decoding device corrects the offset amount in the slice basis using the key of the reproduced signal. The picture signal can be scrambled in this manner without modifying the MPEG system.