摘要:
Blocks of HDTV picture information are selected for transmission at a plurality of channel rates of an HDTV transmitter. The size of each block of HDTV picture information is dependent on a target distortion parameter for the HDTV picture information. As a result of this selection, a portion of each block of HDTV picture information is transmitted at the lower channel rate, with the result that the HDTV transmitter range is maximized while maintaining a picture quality for the resulting HDTV video image.
摘要:
Encoded blocks of video information are selected for transmission at a plurality of channel rates based on the corresponding location of the portions of the video image represented by the encoded blocks. Each encoded block is designated an image type which determines its transmitted channel rate. The image types are associated with spatial positions of a video image such that encoded blocks within a first area of the video image are designated a first image type and encoded blocks within a second area of the image are designated a second image type. In general, data blocks representing the central portion of the video image are transmitted at a channel rate having less susceptibility to noise or other degradation, thereby ensuring that such portion can be received in fringe areas.
摘要:
To minimize distortion, a sequence of phase modulated signal elements (data symbols) are combined in accordance with a predetermined shaping (weighting) function by a transversal filter augmented with a baud rate control circuit. The transversal filter includes a plurality of multipliers, located at taps along a delay line, forming products between data symbols and coefficients representing segments of the predetermined weighting function. The baud rate control circuit shifts the phase of the delayed data symbols and delivers these "extended" data symbols to certain multipliers. By digitally processing segments of the weighting function and portions of an overall data symbol this invention yields to compact construction.
摘要:
Apparatus for decoding a stream containing codes of a variable length code (VLC) takes advantage of the fact that a trie representation of the VLC can be pruned to leaves that each represent a complete binary trie. Combinational circuits or ROMs are then employed to decode the pruned trie, thereby substantially reducing the complexity of decoding a VLC. In one embodiment the decoding problem is partitioned into segments by considering a few bits at a time, starting with the most significant bits. Each segment either outputs a valid code or informs the next segment that the decoding process is incomplete and provides information to assist the next segment in its decoding effort. In applications where the VL code can be selected for greater efficiency of the decoder, the offered VL code can be restructured to minimize the number of k-nodes, to thereby minimize the pruned trie, and to concomitantly minimize the sizes of the ROMs in the decoder.
摘要:
In a data receiver (100), sampling circuitry (120, 125) forms samples of a received data signal representing a succession of data symbols. The samples, which are formed at twice the symbol rate, are multiplied by respective ones of a queue of coefficients in a fractionally spaced equalizer (150). Further circuitry (155, 160, 165, 170) forms decisions in response to the resulting products as to the values of the tansmitted symbols and generates error signals. The values of the coefficients are updated in the equalizer in response to the error signals. Timing recovery circuitry (230) within the equalizer periodically identifies the largest of the coefficients and either advances or retards the phase of the sampling circuitry depending on whether that coefficient is or is not within a predetermined portion of the queue. The magnitude of the amount by which the phase is advanced or retarded is determined by the position of the largest coefficient relative to the center of the coefficient queue.
摘要:
A method, system and apparatus for adapting the multimedia content for presentation by an application that uses, processes or otherwise services the multimedia content (“multimedia application”) is provided. The method includes receiving the multimedia content formatted in accordance with at least one of a plurality of multimedia protocols; using a function abstracted from the plurality of multimedia protocols to adapt the multimedia content in accordance with one or more capabilities of the multimedia application; and sending the multimedia content so adapted to the multimedia application for presentation.
摘要:
A data signal receiver (100) forms line samples of a received modulated data signal and applies them to a fractionally spaced equalizer (150). The equalizer outputs are demodulated and decisions are formed as to the values of the transmitted data symbols. The equalizer itself is comprised of a plurality of equalizer sections (220, 240, 260, 280) each of which multiplies ones of the line samples with respective ones of a queue of coefficients to form a partial sum. The partial sums are combined to form the overall equalizer output. Timing recovery and tap rotation control signals generated within the equalizer are generated as a function of the location within the coefficient queue of a reference coefficient, the latter illustratively being the coefficient of largest complex magnitude. An arbitration circuit (680) within each equalizer section determines whether that section holds the reference coefficient. The equalizer section which determines that, in fact, it holds that the reference coefficient enables itself to generate the control signals in question to the exclusion of the other equalizer sections comprising the equalizer.
摘要:
A video encoding system generates (e.g., H.264) single-slice pictures using parallel processors. Each picture is divided horizontally into multiple segments, where each different parallel processor processes a different segment. Each parallel processor (other than the first parallel processor of the uppermost segment) only partially processes the macroblocks in the first row of its segment. Subsequently, a final processor completes the processing of the partially encoded, first-row macroblocks based on the encoding results for the macroblocks in the last row of the segment above and across the segment boundary. The encoding of the first-row macroblocks is constrained to enable the encoding of all other rows of macroblocks to be completed by the parallel processors, without relying on the final processor.
摘要:
A method, system and apparatus for adapting the multimedia content for presentation by an application that uses, processes or otherwise services the multimedia content (“multimedia application”) is provided. The method includes receiving the multimedia content formatted in accordance with at least one of a plurality of multimedia protocols; using a function abstracted from the plurality of multimedia protocols to adapt the multimedia content in accordance with one or more capabilities of the multimedia application; and sending the multimedia content so adapted to the multimedia application for presentation.
摘要:
Apparatus for eliminating the truncation errors associated with a multiplicative leak factor employed in a predictive coding arrangement adds a temporally varying control signal that affects the leak factor multiplication output. Specifically, in one embodiment the leak factor multiplication output is modified by arbitrarily changing, or dithering, the level of the mean signal. In another embodiment, the leak factor multiplication output is modified by effectively dithering the leak factor itself. The latter is accomplished by adding the varying control signal prior to the truncated division which occurs in the leak factor multiplication process.