摘要:
A serial-bit digital processing system uses registers and latches to synchronize samples and justify sign-bits. Nominally each processing block in the system includes a sign extend register preceding an arithmetic element and an output register following the arithmetic element. Input registers of one arithmetic element may merge with output registers of the preceding arithmetic element. Ones of the registers include a serially coupled latch which is selectively controlled to pass serial sample bits or to replicate the sign bit. The respective registers are clocked with one of two clock signals having different numbers of pulses per sample period and the length of the respective registers are selected so that at the terminus of each sample period the bits of each sample in the processing system are appropriately justified.
摘要:
Apparatus and method of synchronizing the component signals of a multi-component augmented television signal between its generation reception are disclosed. The disclosed apparatus includes circuitry which generates a training signal that indicates the position of the first pixel in each horizontal line interval of the video signal. This training signal is inserted into one horizontal line interval of the active video signal for transmission. The receiver includes circuitry which separates the training signal and derives a timing signal from it. The timing signal is used to define the pixel positions of various decoded components of the received video signal to facilitate their combination. The timing signal is also used to align the color subcarrier signal and to generate other carrier and subcarrier signals used in the decoding process. Two training signals are disclosed: a pseudo-random noise sequence and a time-reversed, all-pass filtered, raised-cosine 2T pulse.
摘要:
Circuitry for calculating the square root of a binary number iterates the equation E(K+1)=E(K)+(S-E(K).sup.2) where E(K+1) is the current estimate of the square root of the sample S and E(K) is the previous estimate. The value E(K).sup.2 is estimated in order to reduce the complexity of the hardware. An application is described for real time processing of digital audio signals in serial-bit format.
摘要:
In a video disc mastering system, player control data is conveyed by a block code having framing and field number bits and data for use by a computer external to the player is conveyed by a convolutional code having no framing bits, having error check bits related to a subset of the field number bits conveyed by the player control data and having vertical parity selected to spread data required for predictive and reconstructive error correction over a number of video fields greater than that recorded on one convolution of the disc information track. Data is downloaded to an external computer for interactive player applications by means of a decoder which utilizes the player framing and field number codes conveyed by the player control data to recover the convolutionally encoded data as well as detecting tracking errors to provide a high data transfer rate, orders of magnitude of improvement in word error rates and facilitating new refinements in intrafield track error correction, namely, correction of intrafield track skips occuring after the player control data.
摘要:
A data structure, such as a digital television signal, includes (a) a video stream representing a picture and (b) auxiliary information, such as a closed caption stream. In one embodiment, the picture has an inset window representative of a reduced version of the picture properly overlaid by the auxiliary information. In another embodiment, the data structure has two or more auxiliary information streams, and the picture is used to independently test the auxiliary information processing of each of the auxiliary information streams.
摘要:
A bitstream analyzer for detecting and verifying errors in the bitstream such as inconsistencies of time base and program specific information in real time is disclosed. Frequency tracking is provided with only a single time reference, by tracking the time of reception of various time-elements.
摘要:
In a cable television system an interferer signal is inserted into the video signal for scrambling purposes except during a vertical blanking reference interval containing a reference signal for use by a video equalizer in a television receiver to help reduce multipath distortion such as image ghosts.
摘要:
A video disc tracking information encoding system includes a primary encoder for tracking information on a field-by-field basis and a secondary encoder for conveying a subset of the tracking information every N lines within a field. A video disc player for discs recorded with doubly conveyed complete and partial tracking information includes means for recovering the partial tracking information every N lines, comparing it with the complete tracking information recovered during the start of each field and effecting tracking error correction if the partial tracking information differs from a predetermined subset of the complete tracking information thereby facilitating intra-field track error correction so as to enable rapid correction of tracking errors.
摘要:
A high performance disc record recording system wherein a digital manifestation of the signal to be recorded modulates a first carrier frequency and a temporally displaced analog manifestation of the same signal modulates a second carrier frequency. The modulated carriers are linearly combined for recording in a single record track. The digital signal is encoded for error detection and/or correction. On playback the modulated carriers are separated and demodulated. One of the separated signals is delayed so that the two signals are returned to temporal coincidence. The digital manifestation of signal is reconverted to analog format and utilized as the primary output signal. However, upon detection of errors in the digital signal the analog manifestation of the signal is substituted for the primary signal.
摘要:
A ghost cancelling system includes a ghost cancelling IIR filter and channel modelling circuitry for generating tap weighting coefficients for programming the ghost cancelling IIR filter. The channel modelling circuitry includes means for calculating the sum of all of the generated weighting coefficient values. If the sum exceeds a predetermined value indicative of the IIR filter becoming unstable, the weighting coefficients are conditionally scaled in a manner to reduce the sum, thus tending to reduce the possibility of filter instability.