Abstract: A multichannel sampled system uses a single set of steering bits to reconstruct deleted samples from all channels. The steering bits can be derived from the channel having the greatest bandwidth or amplitude, or by majority voting logic operating on steering bits from all channels.

Abstract: A digital signal processor uses a RAM for signal processing. This allows the transfer function to be easily changed by either hardwired circuitry or a microprocessor. Two RAMs per channel can be used, one processing the signal, while the other has its transfer function changed. The operations of the RAMs can be changed during a portion of the input signal, e.g. blanking times, when the switch over is not objectionable.

Abstract: A tape has a format of the type wherein digital video information is recorded with each frame or field disposed on a set of multiple tracks and with at least one track being intended for replay during scene search modes of operation, only the most significant bits of pixels are recorded on the search tracks.

Abstract: Apparatus for controlling the playback speed of a VTR features an accurate speed control signal. The reproduced signal is resynchronized to a standard speed by repeating or deleting frames when successive frames are substantially identical. In addition, or as an alternative, frame averaging can be used. Provision for real time entry is made to minimize human error. Application of the invention to both quadruplex and helical scan machines is shown.

Abstract: A recorded medium moving at some operational velocity is rapidly stepped to advance or retard the position thereof by a preselected time segment relative to a reference clock and the stepping cycle is completed simultaneously with the recorded medium being returned to its operational velocity.

Abstract: A sync generator system for PAL-B television features an offset subcarrier generator that provides an offset subcarrier signal that has phase steps of ninety degree magnitude and occur twice per field. This makes smoothing of a PLL error voltage relatively easy.

Abstract: A color encoding filter for use with a discrete photosensor pickup device has vertical stripes. The stripes occur in repeating cycles of color order, with the ratio of the width of a cycle to the width of a photosensor being a non-integer. This results in wider bandwidth in a luminance signal.The resulting pickup device output signal comprises a double sideband suppressed carrier signal having subcarriers conveying the chroma information. Both subcarriers can be demodulated, however demodulating only the upper sideband reduces biasing.

Abstract: In a VTR of the type having information recorded in adjacent tracks disposed angularly across the direction of tape travel, a search mode playback arrangement is incorporated having a pair of transducer gaps which are alternately enabled to continuously pickup coherent information while the playback arrangement scans across adjacent tracks during a search mode.

Abstract: A television synchronization generator has a clock generator driving a ROM. The ROM has stored in it the required sync signals. In order to conserve the ROM size, the ROM is addressed by a counter except during portions of the sync signals when the amplitude remains a constant. During these portions the counter continues to count.

Abstract: Method and apparatus for replacing defective video information in a video signal line comprises sampling the video signal. Video information from the preceding in-phase pixel and the subsequent in-phase pixel are averaged to form a replacement pixel. Weighting coefficients are generated based upon the amplitude difference between the next adjacent and semi-adjacent pixels having the same subcarrier phase. These weighting coefficients are used to determine the amount of information contribution of the previous and subsequent pixels to arrive at the closest video approximation of the defective pixel. Three times color subcarrier frequency sampling is preferred.

Abstract: A dropout compensator for time spread digital television signals uses either horizontal or vertical averaging to replace a dropped out sample. The choice of direction is made in accordance with whichever direction has the least amount of change around the missing sample or pixel. The circuitry can also be used for chroma invertion when stop or slow motion is to be transmitted or recorded.

Abstract: A TDM scheme has a Y signal that is sampled at 14.32 MHz and every other sample is discarded. The discarded samples are 180.degree. out-of-phase from line-to-line. I and Q signals are sampled at one half this frequency and every other sample is discarded also 180.degree. out-of-phase from line-to-line on a given line. The discarded samples of Q and I are 180.degree. out-of-phase with respect to each other. This allows insertion of the retained I and Q samples into the retained Y samples to allow multiplexing.

Abstract: To continuously correct for tape stretching ("skew"), the phase of timed video information on the tape is compared with a reference at two different times, thereby forming two comparison signals. The two comparison signals are subtracted from each other to form an error signal, which is used to continuously correct the tape length variations.

Abstract: A speed control signal for a record segment is generated from starting speed and starting time information signals, an ending speed information signal, and a signal indicative of the duration of the segment. Provision is made for "pre-roll" (stopping the tape ahead of the exact cue point). Duration can be entered directly or computed from start and end times. The speed control signal is applied to a capstan servo, while a cue logic servo controls a reel servo.

Abstract: A VCO control circuit features a first exclusive-OR gate to the inputs of which are applied signals derived from the VCO to provide an output signal that has a 90.degree. phase shift with respect to a reference signal. A second exclusive-OR gate serves as a phase detector for the output and reference signals and provides, after filtering, a frequency control voltage for the VCO. The control voltage has about the same amplitude regardless of the presence or absence of the reference signal.

Abstract: In order to reduce the amount of hardware required in comparing 8-bit numbers representing digitized video signals, only the four LSB are compared, since if the numbers differ by more than the four LSB, no comparison is desired. This is done by detecting if any of the four MSB are logic "1", and if so, setting all of the four LSB to logic "1".