A method of data encoding input data values of a data set for encoding includes selecting one of a plurality of complementary sub-ranges of a set of code values according to the value of a current input data value, the set of code values being defined by a range variable, assigning the current input data value to a code value within the selected sub-range, modifying the set of code values in dependence upon the assigned code value and the size of the selected sub-range, detecting whether the range variable defining the set of code values is less than a predetermined minimum size and if so, successively increasing the range variable so as to increase the size of the set of code values until it has at least the predetermined minimum size and outputting an encoded data bit in response to each such size-increasing operation, and after encoding a group of input data values, setting the range variable to a value selected from a predetermined subset of available range variable values, each value in the subset having at least one least significant bit equal to zero.

A system utilizing a high throughput coding mode for CABAC in HEVC is described. The system may include an electronic device configured to obtain a block of data to be encoded using an arithmetic based encoder; to generate a sequence of syntax elements using the obtained block; to compare an Absolute-3 value of the sequence or a parameter associated with the Absolute-3 value to a preset value; and to convert the Absolute-3 value to a codeword using a first code or a second code that is different than the first code, according to a result of the comparison.

Video coding systems or apparatus utilizing context-based adaptive binary arithmetic coding (CABAC) during encoding and/or decoding, are configured according to the invention with an enhanced binarization of non-zero Delta-QP (dQP). During binarization the value of dQP and the sign are separately encoded using unary coding and then combined into a binary string which also contains the dQP non-zero flag. This invention capitalizes on the statistical symmetry of positive and negative values of dQP and results in saving bits and thus a higher coding efficiency.

An encoder stage, and corresponding encoded bitstream and decoder. The encoder stage comprises: a variable length encoder for encoding an input signal; and a counter configured to dynamically detect an observed frequency at which different symbols are found to occur within each of a plurality of predetermined portions of the input signal, prior to the symbols of each respective portion being encoded by the variable length encoder. The variable length encoder is configured to encode the symbols of each portion using variable length coding performed in dependence on the observed frequencies detected within the respective portion of the input signal, to generate an encoded bitstream comprising the encoded symbols along with an additional element indicating information regarding the observed frequencies detected for each portion, and to output the encoded bitstream to at least one of a storage medium and a transmission medium for supply to a decoder.

There is provided a computer-implemented method of compressing a baseline dataset, comprising: creating a weight function that calculates a weight for each instance of each unique data elements in the baseline dataset, as a function of sequential locations of each of the instances of each respective unique data element within the baseline dataset, creating an output dataset storing a codeword for each one of the unique data elements, wherein codewords are according to a compression rule defining data elements associated with a relatively higher weight as being associated with codewords that are relatively shorter, dynamically creating the compressed dataset by sequentially iterating, for each current sequential location of the baseline dataset: determining an encoded data element mapped to the respective data element of the current sequential location according to the weight function, and adjusting the codewords of the output dataset according to the current weights to maintain the compression rule.

An image coding method comprising: obtaining current signals to be coded of each of the processing units of the image; generating a binary signal by performing binarization on each of the current signals to be coded; selecting a context for each of the current signals to be coded from among a plurality of contexts; performing arithmetic coding of the binary signal by using coded probability information associated with the context selected in the selecting; and updating the coded probability information based on the binary signal, wherein, in the selecting, the context for the current signal to be coded is selected, as a shared context, for a signal which is included in one of a plurality of processing units and has a size different from a size of the processing unit including the current signal to be coded.

Methods and apparatus are provided for improved entropy encoding and decoding. An apparatus includes a video encoder (200) for encoding at least a block in a picture by transforming a residue of the block to obtain transform coefficients, quantizing the transform coefficients to obtain quantized transform coefficients, and entropy coding the quantized transform coefficients. The quantized transform coefficients are encoded using a flag to indicate that a current one of the quantized transform coefficients being processed is a last non-zero coefficient for the block having a value greater than or equal to a specified value.

Provided is a method of decoding coefficients included in image data, the method including determining a Rice parameter for a current coefficient, based on a base level of the current coefficient; parsing coefficient level information indicating a size of the current coefficient from a bitstream by using the determined Rice parameter; and identifying the size of the current coefficient by de-binarizing the coefficient level information by using the determined Rice parameter.

An idea used herein is to use the same function for the dependency of the context and the dependency of the symbolization parameter on previously coded/decoded transform coefficients. Using the same function–with varying function parameter–may even be used with respect to different transform block sizes and/or frequency portions of the transform blocks in case of the transform coefficients being spatially arranged in transform blocks. A further variant of this idea is to use the same function for the dependency of a symbolization parameter on previously coded/decoded transform coefficients for different sizes of the current transform coefficient’s transform block, different information component types of the current transform coefficient’s transform block and/or different frequency portions the current transform coefficient is located within the transform block.

An audio encoder for encoding segments of coefficients, the segments of coefficients representing different time or frequency resolutions of a sampled audio signal, the audio encoder including a processor for deriving a coding context for a currently encoded coefficient of a current segment based on a previously encoded coefficient of a previous segment, the previously encoded coefficient representing a different time or frequency resolution than the currently encoded coefficient. The audio encoder further includes an entropy encoder for entropy encoding the current coefficient based on the coding context to obtain an encoded audio stream.