Abstract: A computer system includes a plurality of subsystems cooled by a cooling flow; at least one redirection device, a management module, and a blower for generating the cooling flow. The redirection device is associated with at least one subsystem and operable to redirect at least a portion of the cooling flow away from the subsystem. The subsystems, the at least one redirection device, and the blower are disposed along a common cooling flow path. The management module is configured to determine cooling requirements of the subsystems and to control the operation of the blower and the at least one redirection device to maintain a specified amount of cooling to the subsystems and to reduce acoustical noise generated by the blower.

Abstract: A method and system for providing performance estimations for a specified power budget provides an indication of the impact on processing performance when closed-loop power/performance control is employed to meet the specified power budget. A workload, which may be the actual workload, or a test workload is run to determine actual power consumption at intervals during the execution of the workload. The power values are examined and if they exceed the specified budget, which may be one of multiple possible budget values, an estimate of the amount by and duration for which the closed-loop power/performance control would have to reduce the performance of the system for each interval in order to provide an estimate of actual performance for the budgetary level(s). The estimate is informed by tests of the workload at each power/performance level to provide a non-linear estimate of the relationship between performance and power for the particular workload.

Abstract: A histogram difference method and system for power/performance measurement and management has low data storage requirements while supporting multiple monitoring applications having different update rates. Histogram data for power usage and/or performance mode is collected at a predetermined rate and the histogram data is read out at periodic intervals by the monitoring applications. The monitoring applications subtract the histogram data from previously read histogram data set to determine a interval difference histogram. The minimum and maximum values for the interval are the lowest-valued and highest-valued bin in the interval difference histogram that have a count greater than zero. The average value for the interval is the mean of the interval difference histogram. A conservative bound of the maximum and minimum values for a system can be determined by adding the values of the maximum and minimum values determined for each subsystem in the system.

Abstract: Method and system for providing user-controlled, continuous, synchronized variable-speed playback of a previously recorded digital audio/video presentation. The user directly controls the rate of playback and the audio and video remain synchronized. The audio is expanded or compressed using the time domain harmonic scaling method so that the pitch of the audio remains undistorted. Synchronization is maintained by allowing one clock to serve as the master time clock for the system. The clocks which can serve as the master time clock include the audio decoder clock, the video decoder clock, and the system clock. The invention is particularly useful in multimedia display systems designed to display MPEG data.

Abstract: Multi-media computer system diagnostic system for fault isolation in a multi-tasking hard, real-time task environment is described. Hard, real-time multi-tasking operations, particularly those unique to signal processing tasks may be monitored without creating a task processing overload and without delaying the results beyond hard, real-time task deadlines by insertion of a branch instruction in the task execution instructions being examined which cause execution of the task to branch to a diagnostic program. The diagnostic program executes a diagnostic instruction set and captures one or more digital samples characteristic of the operation of the hard, real-time task at the point in its program execution where the branch instruction was located.

Abstract: A data processing system is provided for executing multimedia applications which interface with multimedia end devices that consume or produce at least one of (a) real-time and (b) asynchronous streamed data. The data processing system includes a central processing unit for data processing operations including execution of the multimedia application, a digital signal processor for processing data including the streamed data, and a plurality of modular components which cooperate to provide a substantially open architecture.

Abstract: Method and system for providing user-controlled, continuous, synchronized variable-speed playback of a previously recorded digital audio/video presentation. The user directly controls the rate of playback and the audio and video remain synchronized. The audio is expanded or compressed using the time domain harmonic scaling method so that the pitch of the audio remains undistorted. Synchronization is maintained by allowing one clock to serve as the master time clock for the system. The clocks which can serve as the master time clock include the audio decoder clock, the video decoder clock, and the system clock. The invention is particularly useful in multimedia display systems designed to display MPEG data.

Abstract: A multi-media user task (host) computer is interfaced to a high speed DSP which provides support functions to the host computer via an interprocessor DMA bus master and controller. Support of multiple dynamic hard real-time signal processing task requirements are met by posting signal processor support task requests from the host processor through the interprocessor DMA controller to the signal processor and its operating system. The signal processor builds data transfer packet request execution lists in a partitioned queue in its own memory and executes internal signal processor tasks invoked by users at the host system by extracting signal sample data from incoming data packets presented by the interprocessor DMA controller in response to its execution of the DMA packet transfer request queues built by the signal processor in the partitioned queue. Processed signal values etc.

Abstract: Method and apparatus for determining occurrence of an S1 modem identification sequence is disclosed. An S1 sequence is found to exist when the sum of conjugate complex multiplication of signal sample amplitudes taken at an interval T/2 result in a negative scalar value for an arbitrary number of sequential occurrences. Complex samples taken from incoming baseband waveform at twice the modulation rate are interleaved in pairs of two with two even numbered samples and two odd numbered samples being considered separately by first performing complex multiplication followed by scalar multiplication of an output of the complex multiplication and an output of the previous complex multiplication delayed by one modulation interval T. The separate results from the sets of pairs of signal samples are summed to form a scalar whose value when consistently less than 0 indicates the presence of an S1 modem identification sequence in accordance with the CCITT S1 recommendation.

Abstract: A sub-band coder utilizes one or more bit allocation tables to dynamically distribute the channel bit capacity bandwidth among the frequency bands according to the desired output quality of speech rather than by means of complex algorithms or simulation techniques. Multiple bit assignment tables are provided to allow various quality levels to be traded off as increasing bit rate demands are placed upon the transmission system. The technique is used for a single coder to achieve a minimum bit rate for a desired given level of subjective quality in speech output or may be used in a shared bit resource to maintain equal and minimum quality degradation for all users. The quality tables determine the number of bits to be dropped from the encoded representation of each signal sample to minimize the transmission load for a given coder without sacrificing speech quality to an unacceptable degree.