Abstract: Content to be encoded by an encoder may be defined by a sequence of values chosen from a set of possible values. Individual values of the set of possible values may have a probability of occurrence in the sequence of values. The content may form a sequence of frames, such as a video sequence. The encoder may allocate sets of buffers for storage of reference frames, frame contexts (including probability tables), and encoded frames. Individual context buffers (including individual probability tables) may be associated with individual reference frames. Encoding of a particular frame may be based on selecting a particular frame context from a context buffer, the particular probability table therein, and the content of the particular frame.

Abstract: Content to be encoded may be defined by a sequence of values chosen from a set of possible values. Individual values of the set of possible values may have a probability of occurrence in the sequence of values. The set of possible values may have a total probability value. The content may be encoded based on a reduced complexity entropy coding and an interval. The reduced complexity entropy coding may partition the interval into sub-intervals based the probability of individual values that appears in the sequence of values and a reduced complexity partition function. The reduced complexity partition function may have an interval size value reduced by a reduction value less than the total probability value.

Abstract: Systems and methods are described for removing ringing artifacts from a coded image. For each block of coded image data, a direction is identified by selecting a directional block divided into a plurality of pixel lines in one predetermined direction of a set of at least four predetermined directions. The directional block may have a constant value across each pixel line. A parameter related to a sum of a mean-square difference between a pixel value and the pixel average of pixels falling on a pixel line in the directional block that includes the location of the pixel may be calculated for each direction of the set. The direction of the set having a minimum summed mean-square difference is selected as the direction for the block based on the calculated parameter values. A non-linear filter is then applied to each block based on the identified direction for the block.

Abstract: Systems and methods are described for predicting a mode value of a block of an image. Mode values are received for a predetermined number of neighboring blocks of the image. Each mode value may within a predetermined range of integer values. Using a probability table, a probability of each mode value in the range of integers being selected may be computed. The probability table may have a first axis that includes every integer value within the range of integer values, and second axis that includes combinations of the neighboring blocks, each combination of the neighboring blocks representing a binary determination whether or not each neighboring block is equal to a corresponding integer value on the first axis. Based on the computed probabilities, a mode value for the block may be selected and coded by an entropy coder.

Abstract: An apparatus and corresponding method are provided for pyramid vector quantization of video data, including receiving the video data in the frequency domain; and pyramid vector quantizing at least one group of pictures (GOP) from the received video data in accordance with a potentially varying bandwidth, the GOP comprising key frames and predicted frames.

Abstract: Systems and methods are described for encoding quantized vector parameters in a bitstream are described. An exemplary method may include receiving a vector of integers used in a data compression codebook, the sum of the integers equaling a pulse sum. An initial expected magnitude may be determined for a first integer, the initial expected magnitude being based on the pulse sum, a distribution parameter, and a value corresponding to a number of integers in the vector. The actual magnitude of the first integer may be encoded based on the initial expected magnitude of the first integer. The pulse sum may be adjusted using the encoded actual magnitude. Also, the value corresponding to the number of integers in the vector may be reduced by one. Expected magnitudes for each of the remaining integers of the vector may then be calculated recursively.