Koninklijke Philips Corporation N.v.

Other

U.S. Philips Corporation

Johannes H M Korst

Pascal F A Coumans

Nicolaas Lambert

Hong Li

Robert Jochemsen

Stephen Rodney Cumpson

Gerardus W T Van Der Heijden

Rudi J M Wijnands

A personal recorder/playback system () includes a recording agent () configured to transparently receive multiple audio/visual streams from analog and/or digital sources. The streams are temporarily stored in queues () for subsequent analysis. The streams, after analysis, are either discarded, stored permanently in an audio/visual collection (), or used to improve the quality of previously stored streams in the collection. The recording agent () provides features such as virtual channels () and a 'top-ten' list () of most popular stored audio/visual streams.

Real-time recording agent for streaming data from an internet

A method for breathing of scheduling algorithms for a storage device (). The method including: (a) computing a worst-case duration of a breathing cycle (P) for the storage device (); (b) starting a breathing cycle; (c) determining if one of the following becomes true before the end of P: (i) a number of real-time requests is at least a predetermined threshold based on a number of data streams and performance parameters of the storage device; and (ii) a number of pending requests for any single stream becomes more than one; (d) if at least one of (i) and (ii) remain true during the duration of P, starting a subsequent breathing cycle after completion of the breathing cycle; and (e) if both of (i) and (ii) are not true during the duration of P, waiting P time units from the start of the breathing cycle before starting the subsequent breathing cycle.

Methods and apparatus for improving the breathing of disk scheduling algorithms

A multimedia server retrieves blocks of data from a storage medium and supplies the blocks in the form of data streams to users. The streams include a group of high bit rate streams and a group of low bit rate streams. The system has a reader for in a sweep reading data blocks from the storage medium for a selected group of streams and for storing the data blocks in respective buffers. The system further has a scheduler for determining which of the streams is to be serviced, i.e. for which of the streams a block is to be read, in the next sweep of the reader. The scheduler according to the invention is operative to determine to service a low bit rate stream less often than a high bit rate stream.

Multimedia server

The invention relates to a storage system ( ) such as a video on demand system, comprising a plurality of storage units ( ) such as disk drives. Each one of the storage units ( ) has a number of storage zones ( ) with mutually different expected data retrieval times. Data is stored in data units, with each data unit comprising N blocks, wherein N&gE;2. The blocks of a data unit are distributed over the storage units ( ). The blocks comprise redundant information such that any one of a plurality of selections comprising N&minus;K of the N blocks suffices for retrieving the data unit, wherein K&gE;1. For retrieving a data unit from the storage units ( ), a reader determines which N&minus;K of the N blocks to retrieve on the basis of a selection procedure. In accordance with the invention, the selection procedure takes into account the expected data retrieval times in order to optimize bandwidth utilization.

Storage system

In an audio/video server blocks of data are read from a storage medium by a reader and supplied to users in the form of data streams. The storage medium includes a plurality of storage units. The blocks are stored in at least two different and randomly selected storage units. A scheduler controls reading of blocks from the storage medium. For each block to be read, the scheduler selects one storage unit from the storage units in which the block is stored such that the playback load on the storage units is balanced. The scheduler issues a read request to the reader for reading the block from the selected storage unit.

System for retrieving data in a video server

A system, like a video on demand server, retrieves blocks of data from a storage medium,and supplies the data to users in the form of at maximum n,data streams. Upon creation, a data stream is in a new state in which no sufficient data is present for consumption by a user, whereas a user may consume data for a data stream in an active state. A scheduler,repeatedly selects a group of data streams for which a data block of a predetermined size needs to be read and causes a reader,to read the data in one sweep and to store the read data in buffers,The group is formed by active data streams whose associated buffers,have room for storing the data block. The scheduler,variably determines the size of the data block for each next sweeping operation through an expression that, with respect to a number of data streams, is substantially based on an actual number n,of active data streams instead of n,.

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Eindhoven, Netherlands

Johannes H M Korst