Abstract: A computer-aided design method for developing, simulating, and testing a read-channel architecture to be implemented in a VLSI circuit. The method uses a coset operating mode and nonzero-syndrome-based decoding to accelerate the simulation of the read-channel's error-rate characteristics corresponding to different parity-check matrices employed in the read-channel's turbo-decoder, such as a low-density parity-check decoder. The acceleration is achieved through recycling some previously generated log-likelihood-ratio values, which enables the method to sometimes bypass certain time-consuming processing steps therein.

Abstract: In one embodiment, a simulator, e.g., for a hard-disk drive selects for testing a signal-to-noise ratio (SNR) value from a range of ratios and an error-correction codeword pattern from a range of codeword patterns. The simulator simulates a communications channel by applying write noise, inter-symbol interference, and read noise to the codeword pattern to generate a noisy signal. In addition, the simulator adds arbitrary-noise to the codeword to accelerate the speed of the simulation. The arbitrary noise increases the probability of converging on a trapping set and does not represent any noise introduced by the communications channel. The simulator attempts to decode the noisy signal, and if decoding is unsuccessful, then the simulator increments an error counter corresponding to the selected signal-to-noise ratio. This process is repeated for all possible combinations of signal-to-noise ratio values and codeword patterns to determine the error rate for all of the signal-to-noise ratio values.

Abstract: A search method for identifying an intra mode that can produce acceptable video-encoding quality for a pixel block while striking a proper balance between the quality and processor load. In a representative embodiment, the search method relies on a set of mode-selection rules for iteratively identifying candidate intra modes. Each identified candidate is evaluated based on a comparison of its sum of absolute differences (SAD) with the smallest SAD in the set of the previously identified candidates. The mode-selection rules use the comparison results as conditions that efficiently guide the search method toward an intra mode that is suitable for encoding the pixel block with acceptable video quality. On average, a representative embodiment of the search method disclosed herein is advantageously capable of finding a suitable intra mode in fewer iterations than a comparable prior-art search method.

Abstract: In one embodiment, a high-level compensation (HLC) module receives samples of an input signal and determines whether a magnitude of each sample, represented in a linear domain, is relatively low or relatively high by comparing the magnitude to a threshold. If a sample is less than or equal to the threshold, then it is considered to have a relatively low magnitude and the sample is not attenuated. If a sample is greater than the threshold, then it is considered to have a relatively high magnitude and the HLC module attenuates the sample according to a “soft” non-linear function. The “soft” non-linear function is characterized by at least two of the following characteristics: the non-linear function (i) increases monotonically, (ii) forms a convex upwards curve, (iii) has a first derivative at the threshold equal to one, and (iv) has a first derivative at a maximum possible magnitude value equal to zero.

Abstract: In one embodiment, a music detection (MD) module accumulates sets of one or more frames and performs FFT processing on each set to recover a set of coefficients, each corresponding to a different frequency k. For each frame, the module identifies candidate musical tones by searching for peak values in the set of coefficients. If a coefficient corresponds to a peak, then a variable TONE[k] corresponding to the coefficient is set equal to one. Otherwise, the variable is set equal to zero. For each variable TONE[k] having a value of one, a corresponding accumulator A[k] is increased. Candidate musical tones that are short in duration are filtered out by comparing each accumulator A[k] to a minimum duration threshold. A determination is made as to whether or not music is present based on a number of candidate musical tones and a sum of candidate musical tone durations using a state machine.

Abstract: In one embodiment, a pause-based music detection (MD) module detects music by analyzing pauses in a received audio signal. The energy of each frame of the signal is compared to an energy threshold to determine whether the frame corresponds to background noise only (i.e., a pause) or sound such as speech or music. A window having a number of frames is analyzed to determine whether there is a pause within the window. If no pauses are detected in the window, then the current frame is presumed to correspond to music. If a pause is detected, then the current frame is presumed to correspond to speech. In another embodiment, the pause-based MD module output is applied to Boolean “OR” logic along with a tone-based MD module output to generate a final MD decision. The tone-based MD module detects music by analyzing tones in the signal using any suitable tone-based MD algorithm.

Abstract: A video transcoder for converting a compressed input video bit-stream having one spatial resolution into a compressed output video bit-stream having a different spatial resolution in a manner that enables the transcoder to dynamically change the amount of computational resources allocated to the conversion process. In one embodiment, the video transcoder has a plurality of configurable processing paths whose configuration determines the amount of allocated computational resources. Exemplary processing-path configuration changes may include, but are not limited to engaging or disengaging a processing path, redirecting a data flow from flowing through one processing path to flowing through another processing path, and attaching or detaching one or more processing modules to an engaged processing path.

Abstract: A video transcoder for converting a compressed input video bit-stream having one spatial resolution into a compressed output video bit-stream having a different spatial resolution using a plurality of resizing channels. The transcoder has a kernel that partially decodes the compressed input video bit-stream to generate partially decoded video data. The data segments corresponding to picture portions that have both intra- and inter-predicted blocks in close spatial proximity to one another are applied to a mixed-mode resizing channel that is specifically designed for processing such data segments. For each received data segment, the control logic of the channel selects, from a bank of pre-configured resizers, a resizer that is deemed to be most suitable for resizing the image portion represented by that data segment in a computationally efficient manner. The data segment is processed in the selected resizer to generate the corresponding resized-image data.