Abstract: Techniques for evaluating media player performance are described. A particular implementation supplies media to a media player where the media includes a video component which has a waveform that alternates between a first video state and a second video state, and an audio component which has a waveform that alternates between a first audio state and a second audio state. In the supplied media the audio and video components are temporally synchronized in transition between respective first and second states. The process further analyzes corresponding output from the media player to determine an extent to which the audio and video components are temporally unsynchronized.

Abstract: A synchronization separation circuit extracts a synchronization timing signal from a video signal, and a burst gate pulse generator generates a timing pulse signal for gating a color burst signal period. In the color burst signal period restricted by the timing pulse signal, a first counter counts up cycles of a color burst signal at a first timing as a rising edge of the color burst signal and a second counter counts up cycles of the color burst signal at a second timing as a falling edge of the color burst signal. A color burst determination circuit receives count values to determine presence/absence of a color burst signal superimposed on the video signal.

Abstract: A vertical blanking interval (VBI) signal testing tool captures, isolates, and analyzes a VBI signal to determine the quality of the VBI signal or signal source. A digitized VBI signal may be received and analyzed according to industry standards. The VBI signal is examined using thresholds, threshold points, and other points as a way of discerning waveforms in the signal and their individual characteristics. Thereafter, deviations of the VBI signal from industry standards are logged or displayed for review. One feature of the tool records captured VBI data to a persistent storage medium, thereby allowing post-processing of the VBI signal at another time and/or another location. An exemplary analysis program can read the recorded VBI data from the persistent storage medium and perform tests to determine the quality of the VBI signal or signal source. VBI signal translations are also contemplated.

Abstract: To solve the problems in the prior art, the present invention provides a method for measuring a time difference between digital video signals and digital audio signals, wherein said method comprises the steps of extracting respective time series data from respective frequency domains of said digital video signals and said digital audio signals; statistically identifying the cross-correlation of said time series data in said frequency domains, thereby measuring the time difference between said digital video signals and said digital audio signals.

Abstract: Provided is a method for detecting frame sync and frame structure in a satellite broadcasting system. The method for detecting frame sync and frame structure includes the steps of: calculating differential correlation values of reception symbols; generating index sequences of reception symbols whose differential correlation values calculated above exceed a threshold value; calculating positions estimated as frame start points which correspond to a total frame number based on the number of symbols per frame for each frame structure; and detecting frame sync and frame structure based on the umber of positions where the above-calculated frame start point estimated positions and the above-generated index sequences are matched.

Abstract: A reflective liquid crystal display device combined with an optical system with a wire grid is provided for light modulation by a liquid crystal layer. This layer, made of nematic liquid crystal having negative dielectric anisotropy, is formed such that first and second orientation directions on first and second substrates are rotated by “60±?” and “60±?” degrees in first and second rotating directions starting from a reference direction, respectively. The first and second rotating directions are mutually opposite, the reference direction is parallel to the first and second substrates and within in an angular range defined by a central angle plus ±5 degrees wherein the central angle is ±45 degrees from an oscillation direction of incident polarized light, and a relationship of |?|+|?|?10 (? and ? are zero or positive integers) is fulfilled.

Abstract: Video control signals are received at a video input port of a system. A determination is made whether the video control signals are valid or invalid. When video control signals represent a valid video signal, providing a delayed representation of a control signal to a synchronization input of a display engine of the system, and when the video control signals represent an invalid video signal, providing a an alternative signal to the synchronization input of the display engine.

Abstract: A method and system for synchronizing signals. First and second signals are sent (compressed or uncompressed) from a source to a receiving apparatus of a receiving system. The first signal has content of a first modality (e.g., audio) and the second signal has content of a second modality (e.g., video). The first and second signals are to be displayed on a display apparatus of the receiving system. The first and second signals have been time-synchronized at the source. If the first and second signals are not synchronized in time when received at the receiving apparatus, then the first and second signals may be time-synchronized at the receiving apparatus either manually or through timestamping of both signals at the source, in conjunction with use of a real-time clock at the receiving apparatus.

Abstract: A video synchronization signal detector for detecting occurrences of single and double frequency synchronization signal pulses present during a vertical synchronization interval.

Abstract: A video data stream containing picture video and a vertical synchronization signal is processed in a microprocess that performs statistical evaluation of the frequency of the vertical synchronization signal of the video data stream. The statistical evaluation includes producing the statistical mean value and variance of the frequency of the vertical synchronization signal.

Abstract: A system and method for automatically controlling color synchronization polarity during video decoding. Various aspects of the present invention may comprise at least one module that is adapted to monitor color synchronization polarity at a plurality of instances over a period of time. The at least one module may also, for example, be adapted to generate a sequence of signals indicative of the color synchronization polarity correctness at the plurality of instances. The at least one module may additionally, for example, be adapted to statistically analyze the sequence of signals. The at least one module may further, for example, be adapted to determine, based at least in part on the statistical analysis of the sequence of signals, whether color synchronization polarity is correct. The at least one module may still further, for example, be adapted to control color synchronization polarity based, at least in part, on the polarity correctness determination.

Abstract: A vertical blanking interval (VBI) signal testing tool captures, isolates, and analyzes a VBI signal to determine the quality of the VBI signal or signal source. A digitized VBI signal is received and analyzed according to industry standards. The VBI signal is first examined using thresholds, threshold points, and other points as a way of discerning waveforms in the signal and their individual characteristics. Thereafter, deviations of the VBI signal from industry standards are logged or displayed for review.

Abstract: A video decoder (10) for receiving an input video signal and producing output signals for a digital display (12), and involving automatic gain control (AGC) functions (20, 28), is disclosed. For each of the front-end and back-end AGC functions (20, 28), the AGC gain value applied is modified according to measurements of several attributes of the video signal, such as sync height, color burst amplitude, composite signal peak amplitude, and luma signal peak amplitude. The measurements are made, and the AGC gains are modified, on a frame-by-frame basis. Preferably, the AGC is modified using the one of the signal attributes that indicates the lowest gain. The back-end AGC function (28) modifies its gain to unity if the front-end AGC function (20) selected the luma signal peak amplitude for modifying its gain. A method for adjusting the rate of change of the AGC gain is also disclosed, in which gain increases are delayed and slowed following an AGC gain decrease because of an image-dependent signal attribute.

Abstract: A system and method for determining phase of a subcarrier (e.g., a jittering video subcarrier). Various aspects of the present invention may comprise determining at least one weighting factor based, at least in part, on a subcarrier synchronization signal (e.g., a video synchronization signal). A first subcarrier phase sample and at least a second subcarrier phase sample may then be obtained. Subcarrier phase may then be determined by interpolating between the first subcarrier phase sample and the second subcarrier phase sample, where such interpolation (e.g., linear interpolation) may be based, at least in part, on the determined weighting factor(s).

Abstract: A TMDS receiver includes a plurality of data channels, a clock channel, and an off-line mode detector. Each data channel receives a video signal and the clock channel receives a clock signal. Each data channel comprises a channel decoder for decoding the signals received by the corresponding receiving channel. The off-line mode detector detects an off-line mode detector, and then turns on a plurality of first data channels for a first predetermined period to determine an operation mode of video signal transmitted on said first data channels if the activity of the clock signal is valid. The off-line mode detector also activates a plurality of second data channels among the plurality of data channels according to the operation mode if the operation mode is determined as valid.

Abstract: A system and method transmits data received at varying frequencies at a fixed data rate. The frequency dependent data and associated data clock signal are received and the frequency dependent data is converted to frequency independent data. A ratio of a number of data clock cycles to a number of reference clock cycles is determined and transmitted. The frequency independent data and header data are transmitted, at a fixed rate, to a receiver, the fixed rate being a frequency greater than the frequency of the associated data clock signal. The received the frequency independent data is converted to frequency dependent data based upon the received determined ratio. The communication channel may include an optical fiber and a tension member wherein control data is transmitted along the tension member and graphic data is transmitted along the optical fiber.

Abstract: Method, system, and program product for measuring audio video synchronization. This is done by first acquiring audio video information into an audio video synchronization system. The step of data acquisition is followed by analyzing the audio information, and analyzing the video information. Next, the audio information is analyzed to locate the presence of sounds therein related to a speaker's personal voice characteristics. The audio information is then filtered by removing data related to a speakers personal voice characteristics to produce a filtered audio information. In this phase filtered audio information and video information is analyzed, decision boundaries for Audio and Video MuEv-s are determined, and related Audio and Video MuEv-s are correlated. In Analysis Phase Audio and Video MuEv-s are calculated from the audio and video information, and the audio and video information is classified into vowel sounds including AA, EE, OO, silence, and unclassified phonemes.

Abstract: A phase shifter (70) for correcting the phase of a sub-carrier signal input into a decoder to a burst signal has a phase shift setting (5), a correction amount setting (9?), a phase shifter (6) and a 90-degree phase shifter (7). The phase shift setting (5) holds a phase shift amount for all the scanning lines. The correction amount setting (9?) holds a correction phase shift amount for every part of all the scanning lines. The phase shifter (6) partially shifts the phase of the sub-carrier signal in a unit of part of all the scanning lines, and shifts it in a unit of all the scanning lines, based on said phase shift amount and said correction phase shift amount. The 90-degree phase shifter (7) generates a sub-carrier signal orthogonal to said phase shifted sub-carrier signal.

Abstract: A method and apparatus of detecting a connection status of a digital video apparatus to a peripheral apparatus includes a digital video encoder configured to receive a digital video signal, and convert and output the digital video signal into an analog video signal, and a determination circuit configured to detect a voltage level of a horizontal synchronization signal of the analog video signal in a vertical blanking time determined by vertical synchronization signals, and determine whether the digital video apparatus is connected to a peripheral apparatus based on a detection result of the voltage of the horizontal synchronization signal of the analog video signal.

Abstract: A color frame identifier circuit generates a pseudo-subcarrier signal and compares the pseudo-subcarrier signal to a sliced color burst of at least one selected line in a video frame. Based on this comparison, a processing circuit determines the color frame.

Abstract: An image data transfer circuit and an image data transfer method capable of exception processing without affecting image data of normal frames when an error is detected in image data. Image data applied to an input processing section is filtered by a filter, stored in an FIFO buffer, and sequentially read from an output section for transfer to the outside. In this event, two frame counters count numbers of frames which are being processed in input processing and output processing, respectively. When an error is detected in the input processing section, a stop controller does not output a stop request signal if the two count values do not match, and outputs the stop request signal at the time the two count values match. In this way, operations on error data are stopped after all image data of normal frames stored in the FIFO buffer has been transferred to the outside.

Abstract: Certain embodiments of the invention disclose a method and system for processing in a non-line locked system. The phase relationship between the sub-carrier signal on consecutive video lines in a video comb filter is determined by synchronizing the two video lines. The synchronization is achieved by aligning the color bursts signals in each of the two video lines. The phase error between the two video lines is determined through the use of a correlation operation. The phase error between consecutive video lines is used to automatically adjust the delay lines used by the video comb filter. The line delay adjustment is provided by changing the values of a variable integer delay and a fractional integer delay. Line delay adjustments reduce the artifacts that occur in the separation of luma and chroma components of a composite video signal.

Abstract: Disclosed are methods and systems for automatic level control (ALC) in a video signal processing system. The new ALC of the invention takes into account the gain applied to the video signal, such as that provided by an associated automatic gain control (AGC). Methods and systems of the invention use present gain control values and previous gain control values in quickly converging to a new offset control value.

Abstract: A timing signal transferring circuit (10) that may be arranged to stably transfer a timing signal (S1) between two video signal processing circuits that may operate at different clock frequencies has been disclosed. A first timing signal (S1) may be received from a pre-stage video processing circuit (13). The first timing signal (S1) may be synchronous with a pre-stage system clock (C1) and may be set to the vicinity of a center of a screen by a video signal. A second timing signal (S2) may be generated on the basis of first timing signal (S1) and transferred to a post-stage video signal processing circuit (14). Second timing signal (S2) may be synchronous with a post-stage system clock (C2). In this way, a disturbance or distortion of a video on a screen due to a difference in system clock frequency affecting a video signal in the post-stage circuit may be reduced or eliminated.

Abstract: To match the output frame rates to the input frame rates, a display clock signal is generated that has a frequency locked to the frequency of a reference clock signal. To generate the display clock signal, the period of the vertical incoming data clock is measured using the reference clock signal. The number of pixels disposed in the output frames is subsequently divided by the measured period. A fractional-N phase-locked loop circuit is adapted to multiply the result of the division with the frequency of the reference clock signal to generate the display clock signal. The display clock signal is also locked to the reference clock signal.

Abstract: The present invention relates to a system and method for generating a blanking period indicator signal from sync information in video timing. The invention comprises an auto polarity detect processor adapted to automatically detect the polarity of at least one sync signal and a generation processor adapted to generate a DE signal.

Abstract: A system and method providing dynamic detection and correction of data corrupted by external interference in wireless communications network includes an interference detection unit and correction unit. Detection unit detects impact on video signals based on measuring condition of predetermined portion of video signals. Correction unit corrects the interference by selecting previously stored data to replace corrupted video data.

Abstract: A system clock generation module varies an oscillation frequency and outputs a frequency diffused clock as a system clock. A synchronizing signal measurement module measures a synchronizing signal characteristic value, which includes at least a synchronizing signal period and a synchronizing signal cycle corresponding to an input image signal, relative to a measurement clock generated from the system clock as a reference. An image signal analyzing module determines that specification of the input image signal is changed when the observed synchronizing signal characteristic value is out of a predetermined range, while determining that the specification of the input image signal is unchanged when the observed synchronizing signal characteristic value is in the predetermined range. The image signal analyzing module analyzes the input image signal according to a result of the determination. This arrangement of the present invention ensures stable analysis of the specification of the input image signal.

Abstract: A method and apparatus for providing adaptive horizontal synchronization (sync) signal detection to identify whether a high quality television signal is being received by a television set. The method determines whether no signal is applied, whether a weak signal is applied or a strong signal is applied to the television set by sampling and processing the horizontal synchronization signal. The signals are classified by comparing the sample horizontal synchronization signals to a predefined threshold. The threshold is established based upon the type of source that produced the television signal.

Abstract: A pixel clock frequency is adjusted in response to periodically monitoring the relative positions between a video signal to be displayed and a video signal captured. Image shear of the display signal may be avoided quickly. Adjustments are made to the color burst signal where dramatic changes in the pixel clock frequency result.

Abstract: A method for estimating a level of a predetermined portion of a video signal comprising the steps of determining a location of the predetermined portion of the video signal, sampling the video signal during the predetermined portion and estimating the level as an average of the samples of the video signal during the predetermined portion.

Abstract: A wander gamut display for perturbation analysis is created by determining from a periodic input data signal and a reference clock a frequency offset and frequency drift rate for the input signal. The frequency offset and frequency drift rate are input to respective orthogonal axes of a Cartesian display together with a wander limit bounding box that defines the wander gamut. Values that fall outside the bounding box on the display indicate wander that may result in data errors.

Abstract: A signal processing method and apparatus in which a horizontal and/or vertical synchronizing signal related to a received video signal is monitored to determine if a relatively large change has occurred in the respective vertical and/or horizontal time period such that a change in video signal source may have occurred. Upon the detection of such a change, the operation of a phase lock loop (PLL) such as horizontal phase lock loop (HPLL) and/or vertical phase lock loop (VPLL) circuit is adapted as appropriate.

Abstract: A jitter canceling apparatus is provided for canceling jitter in a video signal. For processing a video signal, using as a reference an internal synchronization signal and an external synchronization signal different from the internal synchronization signal in the jitter canceling apparatus, an external synchronization signal generator generates the external synchronization signal from an external reference signal. A jitter detector detects time difference jitter, which is jitter in a time difference between the internal and external synchronization signals. The external synchronization signal generator controls the external synchronization signal generating operation in response to the detected time difference jitter to reduce the time difference jitter.

Abstract: A technique to stabilize subcarrier generation in a line-locked digital video system, caused by simultaneous locking of the genlock device causing continuous changing of a shared clock signal, by calculating a time shift occurring in an output waveform, converting the time shift into an equivalent phase shift and sending a corresponding phase correction number to a waveform generator block to correct the time shift, and thus stabilize subcarrier generation.

Abstract: A method for detecting and correcting an error of a device in which a malfunction of a horizontal/vertical processor used in an image display device is detected and corrected. A microcomputer initializes the horizontal/vertical processor, determines whether the horizontal/vertical processor is activated, sets an error check state for a malfunction check of the horizontal/vertical processor if the horizontal/vertical processor is activated, checks whether the horizontal/vertical processor has malfunctioned, and returns to the initialization step if the horizontal/vertical processor has malfunctioned. Accordingly, a malfunctioning horizontal/vertical processor can be rapidly converted to a normal operation state, and a damage to a product occurring due to the malfunction is prevented in advance to stabilize the quality of the product.

Abstract: A method for detecting a synchronous signal contained in an input image signal is provided. In the method, horizontal and vertical periods are established during which horizontal and vertical synchronous signal pulses contained in the input image signal are counted, respectively. Then, minimum and maximum horizontal values which correspond to the horizontal synchronous signal pulses contained in the horizontal period are established, and minimum and maximum vertical values which correspond the vertical synchronous signal pulses contained in the vertical period are established. Afterwards, the horizontal and vertical synchronous signal pulses are counted during the horizontal and vertical periods to respectively obtain first and second counted values.

Abstract: The present invention relates to a system and method for generating a blanking period indicator signal from sync information in video timing. The invention comprises an auto polarity detect processor adapted to automatically detect the polarity of at least one sync signal and a generation processor adapted to generate a DE signal.

Abstract: Disclosed is a period measuring device comprising a clamping circuit to which a synchronizing signal in an input image signal is inputted, a comparator for removing noise in the synchronizing signal outputted from the clamping circuit, period measuring circuit for measuring the period of the synchronizing signal on the basis of the synchronizing signal obtained by the comparator, judging circuit for judging whether or not the period of the synchronizing signal which has been measured by the period measuring circuit is stable, and a control circuit for controlling, when the judging circuit judges that the period of the synchronizing signal is not stable, a threshold voltage of the comparator such that the period of the synchronizing signal is stabilized.

Abstract: A synchronization pulse detector for detecting a synchronization pulse within an input signal. The input signal has “level” portions (i.e., substantially non-time varying portions) and “transition” portions (i.e., substantially time varying portions). The pulse detector includes a pulse shape detector for determining each time the input signal has a sequence of a first “level” portion, followed by a first “transition” portion, followed by a second “level” portion, followed by a second “transition” portion followed by a third “level” portion, one of the first and second “transition” portions being positive and the other one of the first and second “transition” portions being negative. Each time such sequence is determined a pulse_shape detected pulse is produced. An evaluator is provided to reject invalid pulse_shape detected pulses.

Abstract: A monitoring apparatus connected to a TV set selects, from a plurality of internal sources, such as VHF/UHF and BS tuners and built in said TV, and a plurality of external sources connected to the TV set from the outside thereof, such as a CATV tuner and a VCR, the source of video currently displayed on a cathode-ray tube of the TV set by comparing a sync signal of the video signal applied to the cathode-ray tuber and a sync signal of the video signal output from each source. Then the monitoring apparatus determines the currently selected channel by comparing a sync signal of the video signal output from the currently selected source and a sync signal of a video signal of each of broadcast channels generated by reference receivers in the monitoring apparatus independently of the TV set.

Abstract: A signal processing method and apparatus in which a horizontal and/or vertical synchronizing signal related to a received video signal is monitored to determine if a relatively large change has occurred in the respective vertical and/or horizontal time period such that a change in video signal source may have occurred. Upon the detection of such a change, the operation of a phase lock loop (PLL) such as horizontal phase lock loop (HPLL) and/or vertical phase lock loop (VPLL) circuit is adapted as appropriate.

Abstract: The invention concerns a method for determining the quality of a video and/or television image signal. In diversity reception installations comprising several receivers, it is necessary to establish a criterion for assessing the reception signals, so as to select the receiver with the best reception. In order to determine the quality of a television image, the interfering impulses appearing in a line after a horizontal synchronization impulse are detected then their parameters are evaluated. The invention is applicable to television receivers, video recorders, diversity reception installations, in particular for mobile installations.

Abstract: This invention describes a method and apparatus for vertically locking input and output video frame rates. The output vertical sync pulse is locked in phase with the input vertical sync pulse, regardless of the input format and frequency. The output resolution, horizontal refresh rate, and delay are all user selectable. Two Phase Locked Loops are connected in series to achieve vertical lock between the input and output frames. Locking the vertical sync pulses between the input and output frames will eliminate mixing of pixels from different input frames in one output frame. The first Phase Locked Loop generates the output pixel clock required to satisfy the user's display preferences but may not precisely represent the desired output pixel clock required for frame locking because current Phase Locked Loops use integer dividers. A second Phase Locked Loop adjusts its output, which is the reference frequency to the first Phase Locked Loop, until a lock is achieved.

Abstract: An embodiment of the present invention provides a signal generator for generating a signal with a predetermined frequency. The signal generator includes a first comparator for generating a first error signal and a second comparator for generating a second error signal. The first and second comparators are coupled to an oscillator configured to receive the first and second error signals and generate the signal having a predetermined frequency. Another embodiment of the present invention provides a signal generator for generating a signal with a predetermined frequency. The signal generator includes a counter for generating a first count, Q_last. The counter is coupled to a ratio counter which generates a signal having a value less than or equal to Q_last. The contents of the ratio counter represent the phase of the signal having a predetermined frequency. The ratio counter outputs the signal having a predetermined frequency.

Abstract: The invention relates to a method and to a system for measuring the quality of digital television signals comprising a data stream, the method including measuring quality and producing measurement signals that are representative of quality. The method comprises the following steps: a) selecting a reference time signal (PCR) from the data stream; b) generating a multibit digital clock signal (STC′) from the reference time signal, the phase of the clock signal being locked on the basis of the reference time signal (PCR) and its count being deduced unambiguously from the count of an initial time base (STC); and c) labelling the measurement signals with at least some of the bits (HDT) of the digital clock signal that are meaningful given the nature of the measurements performed.

Abstract: This invention describes a method and apparatus for vertically locking input and output video frame rates. The output vertical sync pulse is locked in phase with the input vertical sync pulse, regardless of the input format and frequency. The output resolution, horizontal refresh rate, and delay are all user selectable. Two Phase Locked Loops are connected in series to achieve vertical lock between the input and output frames. Locking the vertical sync pulses between the input and output frames will eliminate mixing of pixels from different input frames in one output frame. The first Phase Locked Loop generates the output pixel clock required to satisfy the user's display preferences but may not precisely represent the desired output pixel clock required for frame locking because current Phase Locked Loops use integer dividers. A second Phase Locked Loop adjusts its output, which is the reference frequency to the first Phase Locked Loop, until a lock is achieved.

Abstract: Disclosed are method and apparatus which measure signal level of an RF signal. The measured RF signal includes a baseband signal modulated onto a first carrier signal having a first frequency and the baseband signal includes program information and control information. The method and apparatus digitize the RF signal which includes the baseband control information and determine a signal level measurement from the baseband control information in the digitized RF signal. Furthermore, method and apparatus are disclosed which determine from the digitized RF signal whether a tagging signal is present in the RF signal.

Abstract: A switched digital video broadcast network provides in-service testing of digitized broadcast video signals subject to analog-to-digital and digital-to-analog conversion. The network includes a plurality of gateways, each gateway coupled to video signal sources and sink. Video frames transmitted on the network are subject to analog-to-digital and digital-to-analog conversion and compression in an MPEG 2 encoder/decoder. Each gateway and includes a test pattern generator and test measurement analyzer for in-service testing of the video signals. The test pattern generator inserts a test signal on pre-selected lines (22, 23 or 261,262) in a Video Blanking Interval (VBI) and time periods of a video frame. The test signal may be dynamically placed at any location in the frame using concealment techniques The video lines are not seen by television viewers.

Abstract: A technique to stabilize subcarrier generation in a line-locked digital video system, caused by simultaneous locking of the genlock device causing continuous changing of a shared clock signal, by calculating a time shift occurring in an output waveform, converting the time shift into an equivalent phase shift and sending a corresponding phase correction number to a waveform generator block to correct the time shift, and thus stabilize subcarrier generation.