Abstract: A video data transmission method and apparatus for transmitting video encoded data with intra-coded video data portions therein suitable for selective high speed reproduction. A first entry point is detected in the encoded data which corresponds to the position of a first intra-coded video data portion. At least one packet is generated on the basis of the decoded first entry point that includes position information relating to at least one second entry point and at least one additional information relating to the video encoded data. The second entry point exists in a forward direction or in a backward direction relative to the first entry point and corresponds to position of at least one second intra-coded video data portion. The packet is multiplexed at a predetermined position of the video encoded data, wherein the multiplexed video encoded data is suitable for selective high speed reproduction of the intra-coded video data portions.

Abstract: An apparatus and method for preparing a variable-rate coded signal, generated by compressing a digital input signal using a variable compression ratio and including a signal portion of a predetermined type, for recording on a recording medium. In the apparatus, a circuit generates a flag signal indicating the signal portion of the a predetermined type in the variable-rate coded signal. A signal-type marker generating circuit generates a signal-type marker in response to the flag signal. Finally, a circuit multiplexes the signal-type marker with the variable-rate coded signal to produce a multiplexed signal for recording on the recording medium. The signal-type marker is located adjacent to the signal portion of the predetermined type to indicate the signal portion of the predetermined type in the multiplexed signal.

Abstract: A data demultiplexer for separating multiplex data including at least coded video data, coded audio data, timing data indicative of a video decoding start time, timing data indicative of an audio decoding start time, and timing data indicative of a system clock reference time. The demultiplexer comprises a circuit for separating the multiplex data into the component data, and comparators for comparing input data with the reference timing data. When the timing data indicative of a video decoding start time is inputted and detected, the video data is written in a video code buffer at the maximum transfer rate. During such time period, the reference timing data indicative of the current time is monitored, and the operation of decoding the video data is started when the reference timing data has become equal to the video timing data.

Abstract: A multiplexed data stream is formed by encoding a first input signal at a variable bit rate to form a first encoded data signal which is temporarily stored in a first storage device, encoding a second input signal at a constant bit rate to form a second encoded data signal which is temporarily stored in a second storage device, and using a multiplexing circuit to multiplex the first and second encoded data signals respectively stored in the first and second storage devices to form the desired multiplexed data stream. Transfer of the first encoded data signal from the first storage device to the multiplexing circuit is controlled on the basis of a quantity of the first encoded data signal that is present in the first storage device. When none of the first encoded data signal is present in the first storage device, transfer of the first encoded data signal to the multiplexing circuit is temporarily halted.

Abstract: A method and apparatus for reproducing pictures from a recording medium in search mode wherein each picture is recorded in the recording medium in the form of a coded signal. The coded signal is coded in either an intra-picture coding mode or an inter-picture coding mode. The coded signal of a picture coded in the intra-picture coding mode is an I-picture; the coded signal of a picture coded in the inter-picture coding mode with only forward prediction is a P-picture; and the coded signal of a picture coded in the inter-picture coding mode with bidirectional prediction is a B-picture. The pictures are reproduced from a read position on the recording medium. To provide an increased number of pictures in search mode, the read position is changed to a first read position, and an I-picture is immediately reproduced from the recording medium at the first read position. Then, at least one B-picture or one P-picture is immediately reproduced from the recording medium following the I-picture.

Abstract: A method of generating a bit stream by multiplexing non-compressed auxiliary information with an information stream. The information stream is obtained by compressing fixed-size units of an information signal with a varying compression ratio to provide varying-sized units of the information stream. The auxiliary information is for use in subsequently processing the information stream. Units of the auxiliary information correspond to the units of the information signal. In the method, the information stream is divided in time into information stream portions. The non-compressed auxiliary information is also divided in time into auxiliary information portions. The information stream portions and the auxiliary information portions are interleaved to provide the bit stream. Finally, the information stream dividing, auxiliary information dividing, and interleaving steps are controlled by emulating decoding of the bit stream by a hypothetical system target decoder.

Abstract: An apparatus and method for preparing a variable-rate coded signal, generated by compressing a digital input signal using a variable compression ratio and including a signal portion of a predetermined type, for recording on a recording medium. In the apparatus, a circuit generates a flag signal indicating the signal portion of the a predetermined type in the variable-rate coded signal. A signal-type marker generating circuit generates a signal-type marker in response to the flag signal. Finally, a circuit multiplexes the signal-type marker with the variable-rate coded signal to produce a multiplexed signal for recording on the recording medium. The signal-type marker is located adjacent to the signal portion of the predetermined type to indicate the signal portion of the predetermined type in the multiplexed signal.

Abstract: A compressed video signal and a compressed audio signal decoding apparatus which including a local access unit counter intended for digital AV applications where access unit headers (e.g. frame headers, audio unit headers or other kind of data unit headers) may be lost or generated by storage media or transmission errors. In order to prevent a resulting AV sync error a value called "access unit count" is included in each elementary stream. With this value each decoder can detect lost or false access unit headers, and correct the AV synchronization. In order to support editing, an extra bit can be added to indicate discontinuity in the access unit count.

Abstract: An interframe motion predicting method for prediction of the motion in a bidirectionally predictive-coded frame from an intra-coded frame and a predictive-coded frame, predicts the motion in another bidirectionally predictive-coded frame from the preceding bidirectionally predictive-coded frame and the predictive-coded frame. A picture signal coding apparatus executes orthogonal transformation of a picture signal, then quantizes the transformed data, and codes the data thus quantized. The apparatus includes a local decoder for the quantized data; first and second memories for storing the decoded picture data of an intra-coded or bidirectionally predictive-coded frame, and a predictive-coded frame respectively; a predictive picture generator for generating a predictive picture of a second bidirectionally predictive-coded frame; and a difference calculator for calculating the difference between the predictive picture and the original picture signal corresponding thereto.