Abstract: Implementations are provided herein for establishing a failover cluster in a distributed file system that upon the occurrence of failover event, allows clients to actively migrate during ongoing file system activity from a source cluster to a target cluster without having to unmount an NFS export from the source cluster and remount the NFS export on the target cluster. Upon the occurrence of a failover event, clients can be rerouted to a target cluster that contains mirrored copies of the data the client was expecting to be stored on the original source cluster. However, in attempting to access the data, without unmounting and remounting an export, the client will continue to reference source cluster FSID and LIN identifiers when making NFS calls to the target cluster. Thus, implementations are provided herein for translating the requests of an NFS client on a target cluster after a failover event has occurred.

Abstract: A system and method for detecting a sampling clock offset of an analog-to-digital converter used to digitize an analog image signal. A method comprises buffering samples of an analog image signal, computing a value of an autocorrelation function using the buffered samples and a delayed version of the buffered samples, and repeating the computing a value for delays in a range of delays. The method also comprises computing a sampling frequency offset from the values of the autocorrelation function and changing a sampling frequency using the sampling frequency offset.

Abstract: A method and apparatus for an analog-to-digital video signal converter. The converter is controlled by a clock with controllable frequency and phase for sampling an analog signal. A circuit corrects the clock frequency using a period of a columnar frame differences as a function of columnar location. The sampling clock frequency is changed by an amount dependent on the period of the columnar differences. A second measure of the difference between successive frames is computed for a sequence of clock phases. The frequency of the clock is verified using a characteristic of the second measure. The characteristic can be the ratio of the maximum to the minimum of the second measure over selected clock phases. Other characteristics can be used such as a difference of a maximum and a minimum measure.

Abstract: A method and apparatus for an analog-to-digital video signal converter. The converter is controlled by a clock with controllable frequency and phase for sampling an analog signal. A circuit corrects the clock frequency using a period of a columnar frame differences as a function of columnar location. The sampling clock frequency is changed by an amount dependent on the period of the columnar differences. A second measure of the difference between successive frames is computed for a sequence of clock phases. The frequency of the clock is verified using a characteristic of the second measure. The characteristic can be the ratio of the maximum to the minimum of the second measure over selected clock phases. Other characteristics can be used such as a difference of a maximum and a minimum measure.

Abstract: A method and apparatus for an analog-to-digital video signal converter. The converter is controlled by a clock with controllable frequency and phase for sampling an analog signal. A circuit corrects the clock frequency using a period of a columnar frame differences as a function of columnar location. The sampling clock frequency is changed by an amount dependent on the period of the columnar differences. A second measure of the difference between successive frames is computed for a sequence of clock phases. The frequency of the clock is verified using a characteristic of the second measure. The characteristic can be the ratio of the maximum to the minimum of the second measure over selected clock phases. Other characteristics can be used such as a difference of a maximum and a minimum measure.

Abstract: A method and apparatus for an analog-to-digital video signal converter. The converter is controlled by a clock with controllable frequency and phase for sampling an analog signal. A measure of the difference between successive frames of the image is computed for a sequence of clock phases. The measure can be a count taken over pixels of the magnitude of the difference between a pixel in one frame and the corresponding pixel in a following frame exceeding a threshold value. The frequency of the clock is verified using a characteristic of the frame difference. The characteristic can be the ratio of the maximum measure to the minimum measure over the selected clock phases. Other characteristics can be used such as a difference of a maximum and a minimum measure.

Abstract: A system and method for detecting a sampling clock offset of an analog-to-digital converter used to digitize an analog image signal. A method comprises buffering samples of an analog image signal, computing a value of an autocorrelation function using the buffered samples and a delayed version of the buffered samples, and repeating the computing a value for delays in a range of delays. The method also comprises computing a sampling frequency offset from the values of the autocorrelation function and changing a sampling frequency using the sampling frequency offset.

Abstract: A system and method for detecting sampling frequency in a video signal. A method comprises applying a first test to determine the sampling frequency of the image signal, applying a second test to determine the sampling frequency of the image signal, and verifying the sampling frequency of the image signal. The first test compares detected timing characteristics of the image signal with known timing characteristics of a set of known standard image signals and the second test measures data characteristics of image data in the multiple image frames of the image signal. Combining both detected image characteristics and measured image characteristics based techniques to determine sampling frequency improves the possibility of correctly detecting an image signal's sampling frequency.