Sony Corporation

Yoshikatsu Niwa

Shinya Masunaga

Takeshi Funahashi

Tomoaki Takemura

Tsunemitsu Takase

Junichi Otani

Goro Fujita

Minoru Tobita

Shinichi Nakao

Susumu Tosaka

Sunao Aoki

Kiyoshi Ohmori

Satoshi Otsuka

Koji Obata

Tomoyuki Sato

Takahiro Ichikawa

Akihiro Muto

Sumihiro Okawa

Kuniyuki Manaka

A reception apparatus receiving a stream delivered by multicast through a network includes: a stream receiving a stream of a first channel as a viewing stream and one or more streams of second channels as viewing candidate streams; a buffer section storing the streams of the channels received by the stream reception section; a reproduction processing section performing processing for viewing the stream stored as the viewing stream in the buffer section; and a channel causing, when an instruction to switch over, as a viewing target, from the first channel to any one of the second channels of the streams being received as the viewing candidate streams is input, the reproduction processing section to process as the viewing stream the stream corresponding to the second channel and stored in the buffer section, and the stream to receive the stream as the viewing stream.

Reception apparatus and method for reducing time delay in channel switching

A content reproduction apparatus is provided for reproducing variable-speed content. The content reproduction apparatus includes a data acquisition section for obtaining first streaming data and second streaming data, wherein the first streaming data includes first reproduction time data indicating a time to reproduce the first streaming data at a first streaming speed, and wherein the second streaming data includes second reproduction time data indicating a time to reproduce the second streaming data at a second streaming speed. The content reproduction apparatus also includes a reproduction time acquisition section for calculating a third reproduction time according to the first reproduction time data, the second reproduction time data, and a relationship between the first streaming speed and the second streaming speed, the third reproduction time being a time to reproduce the first streaming data at the first streaming speed followed by the second streaming data at the first streaming speed.

Content reproduction apparatus, content reproduction method, and program

A content reproduction method is provided, which acquires, from a data transmission apparatus, first streaming data that is used to play a content at a first speed, and records the first streaming data on a storage medium. The content reproduction method plays the content at the first speed, based on the stored first streaming data. The content reproduction method also starts acquisition of second streaming data in response to a varied-speed reproduction request for the content, wherein the second streaming data is used to play the content at a second speed, and plays the content at a transition speed based on the stored first streaming data, in response to the varied-speed reproduction request. The content reproduction method plays the content at the second speed based on the second streaming data, after the acquisition of the second streaming data progresses to a reproduction preparation complete state.

Content reproduction appratus, content reproduction method, and content reproduction system with varied-speed reproduction requests

There is provided a receiving device including: a receiving unit that receives a packet stream; an oscillator; a measuring unit that performs a measuring operation; an acquiring unit that reads the newest time stamp read from the packet stream received by the receiving unit and the newest measurement value measured by the measuring unit with a predetermined period, from a point of time when the packet stream starts to be received; a calculating unit that calculates an accumulation value of the time stamps and the measurement values acquired by the acquiring unit; a comparing unit that compares a difference between the accumulation value of the time stamps and the accumulation value of the measurement values calculated by the calculating unit, and a value corresponding to a network jitter; and a frequency control unit that controls the oscillation frequency of the oscillator based on the comparison result by the comparing unit.

Receiving device, clock synchronizing method, and computer program

A content playback device has a processor, a memory, a data acquisition portion that acquires streaming data for content from a data transmission device, and a storage portion that stores the acquired streaming data in a storage medium. The content playback device also has a playback portion that plays back the content based on the stored streaming data, a playback control portion that causes the playback portion to halt playback of the content in response to a halt playback request, and an acquisition control portion. The acquisition control portion causes the data acquisition portion to stop acquisition of the streaming data in response to the halt playback request, and causes the data acquisition portion to restart acquisition of the streaming data in response to a resume playback request. The storage portion stores, in the storage medium, the streaming data acquired in response to the resume playback request, starting from a position at which acquisition of the streaming data was stopped.

Content playback device, content playback method, computer-readable storage medium, and content playback system

Disclosed herein are a communication control method and a network system. When a total band of a priority flow and a best-effort flow in any one of switches SWand SWand hosts Hto Hconnected to a network exceeds a predetermined value, priority control is executed to make the priority flow take precedence of the best-effort flow and flow control is executed to limit the band of the best-effort flow. Thus, priority data such as sounds and moving pictures can be transmitted in a high-quality and reliable transmission without turbulence. As a result, it is possible to provide a communication control method and a network system offering high-quality communications even if transmitted data includes sounds and/or moving pictures.

Communication control method and network system

Whether the node to which data has been sent is connected to a bus is determined according to destination information, and, when it is determined that the node is not connected to the bus, predetermined error information is sent to the data transmission source. Therefore, data re-transmission is prevented and thereby the frequency band of a network is efficiently used.

Data transfer apparatus, network system, and data transfer method

A data transfer system makes more effective use of a band available for the data transfer. In data transfer systems having devices with a different delay time in sending back the data depending on the transfer rate of data, it is possible to make more effective use of the band available for the transfer by transferring predetermined data at a slowest transfer rate within the data transfer system.

Data transfer system, data transfer management apparatus and data transfer method

An optical disk apparatus for driving an optical disk on which a groove wobble corresponding to a signal acquired from frequency modulation of biphase modulated address information, and a mark for representing phase information placed inside the wobble are preformatted, and having the biphase bit count &ldquo;a&rdquo; (&ldquo;a&rdquo; is a natural number) between two of the adjacent marks, and the channel bit count &ldquo;n&rdquo; (&ldquo;n&rdquo; is a natural number) between two of the adjacent marks. The apparatus includes first clock signal production device for generating a first clock signal utilizing an &ldquo;n&rdquo; frequency multiple of the reproduction signal of the clock mark, wobble signal reproduction device for reproducing from the optical disk a wobble signal corresponding to the groove wobble, and frequency demodulation device for acquiring the address information by frequency demodulation of the wobble signal. The frequency demodulation device has a second clock signal generator for generating a second clock signal by frequency dividing a data clock signal supplied from the first clock signal reproduction device by 1/M(M - - - n/(a&middot;s)) in which a clock &ldquo;s&rdquo; (&ldquo;s&rdquo; is a natural number) is an oversampling value of the biphase bit, a waveform shaping unit for acquiring binary values by waveforming the wobble signal, and a detector for acquiring the address information by processing the second clock signal using the binary signal.

Frequency demodulating circuit, optical disk apparatus thereof and preformating device

A frequency demodulating circuit for demodulating a frequency-modulated signal expressing digital data. The circuit includes a waveform shaping circuit for acquiring a binary signal from the frequency-modulated signal and a detector for decoding the binary signal and response to clock signals to obtain the digital data. A circuit also includes a clock signal generating circuit for generating the clock signals which have a frequency of the frequency-modulated signal corresponding to &ldquo;one&rdquo; of the digital data and a frequency higher than the frequency of the frequency-modulated signal by a multiple, which corresponds to a &ldquo;zero&rdquo; of the digital data.

A frequency demodulating circuit, optical disk and preformatting device having a decoder for decoding a bit &ldquo;0&rdquo; and a bit &ldquo;1&rdquo; for reproducing address information recorded as a wobble groove. The decoder determines whether an output is a digital &ldquo;1&rdquo; or a digital &ldquo;0&rdquo; so that even if the waveform of the reproduced signal is erratic or unstable due to a defect, a digital &ldquo;1&rdquo; or a digital &ldquo;0&rdquo; can be correctly identified by utilizing window pulses. Changes in the slop of a zero cross point of the groove wobble are prevented from occurring by making the groove wobble amplitude fluctuate according to the signal frequency modulation which also greatly reduces jitter and allowing satisfactory acquisition of the address information. Oversampling clock signals of biphase bits are generated by frequency division of data clock signals. Since demodulation is accomplished with a single phase lock loop circuit in the data system using clock signals for both the data and the addresses, the configuration can be made extremely simple. By means of polarity of the playback signal mark having phase information, it is determined whether the beam that scans the optical disk is above the land or above the groove. The marks containing phase information are formed on the base disk surface solely by the on and off control of the paired cutting beams with respect to the direction of the time axis, for easy preformatting of a mark to permit acquiring (phase) position information with high precision.

A disk shaped recording medium, drive apparatus and method for driving a medium divided into at least a recordable area and a reproduction only area, are disclosed. Address conversion is carried out by a conversion table so that the leading portion of a logical block address (LBA) when an optical disc is viewed from the host computer side is caused to correspond to the leading physical block address PBA1&equals;RAM_START of a random access memory (RAM) area of the outermost circumferential side of the optical disc. Thus, reproduction can be started from the leading portion of a RAM area disposed at the innermost circumferential side. Even if a read only memory (ROM) area is disposed at the outermost circumferential side, this optical disc can be used as boot device. In addition, since the ROM area can be disposed at the outermost circumferential side, data transfer speed of the ROM area is permitted to be high data transfer speed in an optical disc employing a zone constant angular velocity (CAV) system.

Disk shaped recording medium and drive apparatus utilizing logical block address conversion and start addresses which increase from inner and outer circumferential sides of the medium

A disc drive unit for driving a disc recording medium such as a magneto-optical disc accommodated in a disc cassette, comprises a chassis, a cassette holder having a pair of wall sections and moveable up and down between upper and lower positions with respect to the chassis, and the disc cassette being injectable into and ejectable from the cassette holder, a disc rotating mechanism being moveable up and down between upper and lower positions with respect to the chassis and chucked with the disc recording medium for rotatively driving the disc recording medium, height-level positioning members provided at the chassis, so that at least their upper ends are located at a higher level than the lower wall section of the cassette holder, when the cassette holder is held at its lower position, and a loading motor unit for shifting the cassette holder from its upper position to its lower position and for shifting the disc rotating mechanism from its lower position to its upper position, during loading of the disc cassette.

Disc drive unit

A disc drive unit for a magneto-optical disc accommodated in a disc cassette, comprises a magnetic head for applying a magnetic field to the magneto-optical disc, a magnetic head moving mechanism for moving the magnetic head between a loading and unloading position, an eject mechanism for ejecting the disc cassette, a reversible motor, and a transmission device for transmitting a rotational force of the reversible motor to the magnetic-head moving mechanism by rotation of the motor in its one rotational direction and for transmitting the rotational force of the reversible motor to the eject mechanism in its other rotational direction whereby a controller is provided for controlling the reversible motor so that a rotational speed of the motor in the other rotational direction used for the eject mechanism is faster that the rotational speed of the reversible motor in the one rotational direction used for the magnetic-head moving mechanism in order to ensure the quick ejection of the disc cassette.

A method of accessing a disc-shaped recording medium including the steps of (a) recording defect information on the disc-shaped recording medium including a first logical address data of defective sectors, the first logical address data being a serial logical address data assigned to all sectors including both effective and defective sectors, (b) recording on a predetermined physical location of the disc-shaped recording medium disc information containing recorded physical position information of the defect information which represents a physical data structure, (c) reading out the disc information from the disc-shaped recording medium, (d) reading out the defect information using the physical recorded position information contained in the disc information read out at step (c), (e) generating a first table using the defect information which is used to convert the first logical address data into a second logical address data, the second logical address data being an address data assigned only to the effective sectors, (f) generating a second table using the disc information read out at step (c) which is used to convert the second logical address data into a physical address data of the disc-shaped recording medium, (g) using the first table to convert the first logical address data to be accessed into the second logical address data, (h) using the second table to convert the second logical address data into the physical address data and (i) accessing the disc-shaped recording medium using the physical address data generated at step (h).

Growing community of inventors

Kanagawa, Japan

Yoshikatsu Niwa