Abstract: Methods and devices for reconstructing coefficient levels from a bitstream of encoded video data for a coefficient group in a transform unit, using adaptive-threshold-based level coding. Threshold is set based upon level information from one or more previously-reconstructed coefficient groups in the transform unit. Threshold may be maximum number of level flags to decode for the coefficient group. Level information may include number of level flags decoded in previous coefficient groups. Previously-reconstructed coefficient groups may include coefficient group to the right and below the current coefficient group.

Abstract: A method for encoding video with a two-dimensional (2D) transform separable to two one-dimensional (1D) transforms. The method receives an array of values for a sub-section of an image, performs a first 1D-transform of the array, transposes the resulting array, and performs a second 1D-transform of the array resulting from the transpose. The method, without performing another transpose, generates a data stream using a transposed scan order based on the values of the array resulting from the second transform. A method for decoding video encoded by a 2D transform, which separable to two 1D transforms. The method receives a data stream containing encoded values for an image, parses out the values into an array using a transposed scan order, performs a first 1D-inverse transform on the array, transposes the resulting array, and performs a second 1D-inverse transform of the array resulting from the transpose to produce a decoded output.

Abstract: Encoding data includes: computing a first set of coefficients based on a plurality of transforms each computed over a different portion of an array of data, a second set of coefficients based on a plurality of transforms each computed over a different portion of the array of data, and a third set of coefficients based on a transform computed over the array of data; choosing a set of coefficients to represent the array of data from a group of multiple sets of coefficients, the group including the first set of coefficients, the second set of coefficients, and the third set of coefficients; and encoding the chosen coefficients and one or more parameters related to the chosen coefficients.

Abstract: A method of determining predicted numbers of processor cycles required for respective segments of a media file for playback of the media file, a method of playback of a media file, a method of downloading a media file, a device for playback of a media file and a system for downloading a media file. The method comprising performing a bitstream analysis of the media file to determine a number of non-zero IDCT coefficients of the respective segments, input parameters of an MC task function associated with respective segments, or both; and determining the predicted numbers of processor cycles based on the bitstream analysis.

Abstract: A video encoder identifies one or more portions of a video picture that contain DC shift blocks and adjusts quantization (e.g., by selecting a smaller quantization step size) to reduce contouring artifacts when the picture is reconstructed. The encoder can identify the portion(s) of the picture that contain DC shift blocks by identifying one or more gradient slope regions in the picture and analyzing quantization effects on DC coefficients in the gradient slope region(s). The encoder can select a coarser quantization step size for a high-texture picture portion.

Abstract: An image transforming method, an image transforming apparatus, an image inverse-transforming method, and an image inverse-transforming apparatus are provided. The image transforming method includes the operations of selecting a predetermined frequency area for performing a frequency transformation with respect to an M×N (where M and N are positive integers) input block, acquiring a truncated transform matrix by selecting elements to be used for a generation of transformation coefficients which correspond to the selected frequency area from among elements of an M×N transform matrix, and generating the transformation coefficients which correspond to the selected frequency area by performing the frequency transformation by applying the truncated transform matrix to the M×N input block.

Abstract: In one embodiment, a method for encoding video data is provided that includes receiving an array of transform coefficients corresponding to a luma component or a chroma component of the video data. The method further includes encoding a significance map for the array, where the encoding includes selecting, using a shared context derivation process that applies to both the luma component and the chroma component, context models for encoding significance values in the significance map.

Abstract: A moving picture encoding device for encoding a moving picture constituted of a time sequence of frame pictures by motion compensation, the device including: a reference picture generation section configured to generate a reference picture subjected to predetermined picture processing from a reference frame picture, in accordance with an encoding condition of a predetermined area to be encoded; and a motion compensation section configured to calculate a motion compensation value for the predetermined area to be encoded, by using a generated reference picture subjected to the predetermined picture processing.

Abstract: An improvement to a predictive video encoding method or apparatus that includes selecting a mode class within which to choose an encoding algorithm to encode individual blocks of video information. Rather than implementing each algorithm in each mode class to ascertain an acceptable compression, the improvement eliminates searching through a class of encoding modes based simply on heuristics. The method comprises obtaining statistical information related to previous blocks of encoded video information, determining a mode class within which to chose a particular encoding algorithm based on the statistical information (e.g., heuristics) gathered, choosing an algorithm within the selected mode class using conventional techniques, and encoding the video information according to the chosen algorithm. Statistical information may include quantization parameters, prior encoding decisions, intensity or frequency values, or Hadamard transform coefficients of previously encoded macroblocks.

Abstract: Systems, methods, software, and data structures that provide dynamic ambient lighting synchronized to a video program being watched in a premises are described herein. A video program may be associated with a predefined lighting scheme that specifies or identifies a time-sequenced set of lighting effects (e.g., flashing police lights, sunrise, explosion, etc.) that are to be performed by the dynamic ambient lighting system time-synchronously with the video program. Components of the dynamic ambient lighting system may extract the lighting scheme from video data, parse the lighting scheme into individual lighting effects, and then control a single-color or multicolor light source associated with each of a plurality of light channels (e.g., front right, rear right, front left, rear left, center, and burst channel, among others) based on time-sequenced lighting primitives defined by each lighting effect. Light sources may be wirelessly controlled, e.g., using an IEEE 802.15.4 or ZigBee-compliant wireless system.

Abstract: In general, techniques are described for implementing an 8-point inverse discrete cosine transform (IDCT). An apparatus comprising an 8-point inverse discrete cosine transform (IDCT) hardware unit may implement these techniques to transform media data from a frequency domain to a spatial domain. The 8-point IDCT hardware unit includes an even portion comprising factors A, B that are related to a first scaled factor (?) in accordance with a first relationship. The 8-point IDCT hardware unit also includes an odd portion comprising third, fourth, fifth and sixth internal factors (G, D, E, Z) that are related to a second scaled factor (?) in accordance with a second relationship. The first relationship relates the first scaled factor to the first and second internal factors. The second relationship relates the second scaled factor to the third, fourth, fifth and sixth internal factors.

Abstract: An apparatus comprising a processor configured to generate a rectangular block of transform coefficients comprising applying a discrete separable unitary transform to a rectangular boundary block of a video object, wherein the boundary block comprises at least one masked pixel and at least one unmasked pixel, wherein the transform coefficients comprise a number of zero-valued transform coefficients greater than or equal to a number of masked pixels, wherein the transform coefficients comprise at least one non-zero-valued transform coefficient; and generate an encoded output comprising compressing only the non-zero-valued transform coefficients.

Abstract: An image decoding apparatus includes an entropy decoder, an inverse quantization module, an estimation module, an estimated coefficient value limiting module, and an inverse discrete cosine transformation module. The estimation module performs linear estimation of a correction value of a discrete cosine transformation coefficient to be processed, for an inverse quantization result, based on discrete cosine transformation coefficients in a rectangular area which includes a pixel to be processed and discrete cosine transformation coefficients in an area adjacent to the rectangular area including the pixel to be processed. The estimation coefficient value limiting module limits the correction value such that the correction value estimated by the estimation module falls within a predetermined range based on a quantization step.

Abstract: Encoding data includes: computing a first set of coefficients based on a plurality of transforms each computed over a different portion of an array of data, and a second set of coefficients based on a transform computed over the array of data; choosing a set of coefficients to represent the array of data from a group of multiple sets of coefficients, the group including the first set of coefficients and the second set of coefficients; and encoding the chosen coefficients and one or more parameters related to the chosen coefficients.

Abstract: In general, techniques are described for implementing an 8-point discrete cosine transform (DCT). An apparatus comprising an 8-point discrete cosine transform (DCT) hardware unit may implement these techniques to transform media data from a spatial domain to a frequency domain. The 8-point DCT hardware unit includes an even portion comprising factors A, B that are related to a first scaled factor (?) in accordance with a first relationship. The 8-point DCT hardware unit also includes an odd portion comprising third, fourth, fifth and sixth internal factors (G, D, E, Z) that are related to a second scaled factor (?) in accordance with a second relationship. The first relationship relates the first scaled factor to the first and second internal factors. The second relationship relates the second scaled factor to the third internal factor and a fourth internal factor, as well as, the fifth internal factor and a sixth internal factor.

Abstract: In general, techniques are described for implementing an 8-point discrete cosine transform (DCT). An apparatus comprising an 8-point discrete cosine transform (DCT) hardware unit may implement these techniques to transform media data from a spatial domain to a frequency domain. The 8-point DCT hardware unit includes an even portion comprising factors A, B that are related to a first scaled factor (?) in accordance with a first relationship. The 8-point DCT hardware unit also includes an odd portion comprising third, fourth, fifth and sixth internal factors (G, D, E, Z) that are related to a second scaled factor (?) in accordance with a second relationship. The first relationship relates the first scaled factor to the first and second internal factors. The second relationship relates the second scaled factor to the third internal factor and a fourth internal factor, as well as, the fifth internal factor and a sixth internal factor.

Abstract: Methods, apparatuses and systems for integer transforms, and/or integer transform operations, for transforming data (e.g., residual video data) are disclosed. Included among such methods, apparatuses and systems is an apparatus that may include a processor and memory. The memory may include a set of transform matrices and instructions executable by the processor for transforming data (e.g., residual video data) using any of the set of transform matrices. Each transform matrix of the set of transform matrices may be orthogonal or, alternatively, may be approximately orthogonal and be fully factorizable. Each transform matrix of the set of transform matrices may have a different number of elements. Each element of the respective number of elements is an integer. Differences among norms of basis vectors of each transform matrix satisfy a given threshold, and the basis vectors approximate corresponding basis vectors of a discrete cosine transform (DCT) matrix.

Abstract: A motion compensation module, that can be used in a video encoder for encoding a video input signal, includes a motion search module that generates a motion search motion vector for each macroblock of a plurality of macroblocks by contemporaneously evaluating a top frame macroblock and bottom frame macroblock from a frame of the video input signal and a top field macroblock and a bottom field macroblock from corresponding fields of the video input signal. A motion refinement module, when enabled, generates a refined motion vector for each macroblock of the plurality of macroblocks, based on the motion search motion vector.

Abstract: An image processing method includes decoding encoded image data to generate a decoded image signal including a luma signal and a chroma signal. The method further includes detecting a condition that a reference field has a different parity from a current field and that the number of chroma pixels is vertically different from the number of luma pixels. The method further includes shifting a phase of the chroma signal in the reference field in a vertical plus direction according a value of a motion vector in a vertical direction under the detected condition so that the reference field will coincide in phase of the chroma signal with a current field. The method also includes performing a motion compensation of the decoded image signal using the reference field.

Abstract: A method and device are provided for encoding at least one image broken up into blocks. The method includes, for at least one current block, transforming the current block from the spatial domain into a transformed domain, outputting a transformed block including of a set of coefficients representative of the current block, referred to as original coefficients. The method further includes selecting a subset of original coefficients from the set and, for at least one original coefficient of the subset, the following steps: estimating the original coefficient, outputting an estimated coefficient in the transformed domain; determining a residual of a coefficient by comparing the original coefficient and the estimated coefficient; and encoding the residual of a coefficient.

Abstract: A data processing system for processing a video stream comprises memory array circuitry, memory access circuitry, and video processing circuitry. The memory array circuitry is characterized by a width and a height. The memory access circuitry is operative to cause, through a series of write operations, a series of two-dimensional data representations of different respective regions in a frame of the video stream to be stored in the memory array circuitry. The write operations occur such that only data missing from the memory array circuitry is written to the memory array circuitry during each write operation and such that the data is written modulo at least one of the width and the height of the memory array circuitry. Lastly, the video processing circuitry is operative to perform block matching on the video stream at least in part utilizing the series of two-dimensional data representations stored in the memory array circuitry.

Abstract: A method and system are provided for discriminating areas of content from areas of noise in difference images of a digital video sequence. This allows the fewest bits possible to be used to encode areas of noise according to a video compression algorithm. The method comprises computing a difference frame from current image data and a reference frame; comparing at least one component of a candidate block within the difference frame to a threshold value to discriminate between content and noise; and encoding the candidate block if content is detected.

Abstract: Systems and methods that provide a video stream, the video stream comprising a sequence of plural compressed pictures corresponding to a video program, the plural compressed pictures having plural sets of compressed pictures, each of the plural sets adhering to one or more picture interdependencies, properties, or a combination of the picture interdependencies and properties, and provide auxiliary information in the video stream, the auxiliary information comprising plural data fields, the plural data fields comprising a first data field corresponding to one of multiple possible coding scheme, the coding scheme comprising a set of tiers that uniquely define the one coding scheme, the plural data fields further comprising a second data field different from the first data field, the second data field comprising an indication of whether the one or more picture interdependencies, properties, or a combination of both corresponding to the set of tiers is valid for use in decoding.

Abstract: A single compression engine transmits first and second discrete cosine transform (DCT)-encoded signals. The first DCT-encoded signal uses at most t coefficient bits to represent each of a plurality of DCT coefficients. The second DCT-encoded signal uses at most u coefficient bits, where u is less than t, to represent each of the plurality of DCT coefficients.

Abstract: A packetizing method for packetizing a bit stream in a packetizing apparatus. The packetizing method includes encoding, in an encoding unit in the multiplexing apparatus, a chroma component of image data using a chroma quantization parameter calculated on the basis of a luma quantization parameter weighted by an addition operation that adds a weight parameter and generating the bit stream. The method further includes packetizing, in a packetizing unit in the packetizing apparatus, the bit stream and generating a packetized stream.

Abstract: An apparatus comprising a transform circuit, a first coder circuit, a second coder circuit, and a memory circuit. The transform circuit may be configured to generate (i) one or more first coefficients in response to a sample signal when in a first mode and (ii) the sample signal in response to the first coefficients when in a second mode. The first coder circuit may be configured to generate (i) a first bitstream signal in response to one or more second coefficients when in the first mode and (ii) the second coefficients in response to the first bitstream signal when in the second mode. The second coder circuit may be configured to generate (i) a second bitstream signal in response to one or more third coefficients when in the first mode and (ii) the third coefficients in response to the second bitstream signal when in the second mode. The memory circuit may be configured to store the first coefficients, the second coefficients, and the third coefficients.

Abstract: A multiplexing method for multiplexing a bit stream in a multiplexing apparatus. The method includes encoding, in an encoding unit in the multiplexing apparatus, a chroma component of image data using a chroma quantization parameter calculated on the basis of a luma quantization parameter weighted by an addition operation that adds a weight parameter and generating the bit stream. The method further includes multiplexing, in an multiplexing unit in the multiplexing apparatus, the bit stream and generating a system stream.

Abstract: Methods and apparatus are provided for constrained transforms for video coding and decoding having transform selection. An apparatus includes a video encoder for encoding at least a block in a picture by selecting a particular transform from at least a first transform and a second transform that is different than the first transform, and applying the particular transform to a residue of the block. Transform coefficients for the second transform are selected responsive to a deblocking filter that is present in the video encoder.

Abstract: Techniques are described to reduce rounding errors during computation of discrete cosine transform using fixed-point calculations. According to these techniques, an inverse discrete cosine transform a vector of coefficients is calculated using a series of butterfly structure operations on fixed-point numbers. Next, a midpoint bias value and a supplemental bias value are added to a DC coefficient of the matrix of scaled coefficients. Next, an inverse discrete cosine transform is applied to the resulting matrix of scaled coefficients. Values in the resulting matrix are then right-shifted in order to derive a matrix of pixel component values. As described herein, the addition of the supplemental bias value to the DC coefficient reduces rounding errors attributable to this right-shifting. As a result, a final version of a digital media file decompressed using these techniques may more closely resemble an original version of a digital media file.

Abstract: Several methods and systems for encoding and decoding multimedia data are disclosed. In an embodiment, a system for decoding multimedia data includes a decoding module and an inverse transformation module. The inverse transformation module includes a first inverse transform module, a transpose buffer and a second inverse transform module. The decoding module decompresses encoded multimedia data using a pre-configurable scan order to provide a decompressed matrix of transform coefficients. The first inverse transform module inversely transforms the decompressed matrix of transform coefficients to provide an intermediate output matrix of transform coefficients, the transpose buffer transposes the intermediate output matrix to provide a transposed intermediate output matrix of transform coefficients, and the second inverse transform module inversely transforms the transposed intermediate output matrix of transform coefficients to provide inversely transformed multimedia data.

Abstract: An optimal denoising method for video coding. This method makes use of very few pixels and linear operations, and can be embedded into the motion compensation process of video encoders. This method is simple and flexible, yet offers high performance and produces appealing pictures.

Abstract: Low complexity edge detection and DCT type selection method to improve the visual quality of H.264/AVC encoded video sequence is described. Encoding-generated information is reused to detect an edge macroblock. Variance and Mean Absolute Difference (MAD) of one macroblock shows a certain relationship that is able to be used to differentiate the edge macroblock and the non-edge macroblock. Also, the variance difference of neighbor macroblocks provides a hint for edge existence. Then, a block-based edge detection method uses this information. To determine the DCT type for each block, the detected edges are differentiated as visual obvious edge, texture-like edge, soft edge and strong edge. 8×8 DCT is used for texture-like edges and the 4×4 DCT is used for all the other edges. The result is an efficient and accurate edge detection and transform selection method.

Abstract: Methods and systems are disclosed for removing artifacts, such as blocking noise and contouring effects, from a block-encoded video signal. One method for removing blocking artifacts involves decoding the block-encoded signal to obtain a decoded sequence of video frames and one or more associated motion vectors. By using the motion vector, the location of one or more blocking artifacts may be identified within at least one of the frames. The location identified by the motion vector is filtered to remove at least some of the blocking artifacts. Another method for removing contouring effects involves decoding the block-encoded signal to obtain a decoded sequence of video frames, detecting a contouring effect by evaluating the macroblock mode and DCT coefficient information from the decoded signal, and filtering one or more blocks correlating to the detected contouring effect.

Abstract: Embodiments provide a video camera configured to capture, compress, and store video image data in a memory of the video camera at a rate of at least about twenty three frames per second. The video image data can be mosaiced image data, and the compressed, mosaiced image data may remain substantially visually lossless upon decompression and demosaicing.

Abstract: A method, protocol and apparatus for transporting Advanced Video Coding (AVC) content, e.g., using MPEG-2 systems is disclosed. Specifically, the present method is related to the carriage of various flavors of AVC streams in a uniform fashion over MPEG-2 systems (e.g., both transport and program streams). The method includes generating the AVC content from an input stream, and thereafter transporting the AVC content in a transport stream or a program stream over MPEG-2. The AVC content is generated in accordance with at least one constraint that is associated with the transport stream or the program stream.

Abstract: An image decoding method is for decoding a bit stream in an image decoding apparatus. The method includes receiving the bit stream and a weight parameter that is added to a luma quantization parameter by an addition operation. The method also includes decoding, in a decoding unit in the image decoding apparatus, the bit stream and generating a chroma component of quantized coefficients. In addition, the method includes performing, in a dequantization unit in the image decoding apparatus, dequantization on the chroma component of quantized coefficients using the chroma quantization parameter calculated on the basis of a luma quantization parameter weighted by the weight parameter.

Abstract: System and method for decoding digital video data. The decoding system employs hardware accelerators that assist a core processor in performing selected decoding tasks. The hardware accelerators are configurable to support a plurality of existing and future encoding/decoding formats. The accelerators are configurable to support substantially any existing or future encoding/decoding formats that fall into the general class of DCT-based, entropy decoded, block-motion-compensated compression algorithms. The hardware accelerators illustratively comprise a programmable entropy decoder, an inverse quantization module, a inverse discrete cosine transform module, a pixel filter, a motion compensation module and a de-blocking filter. The hardware accelerators function in a decoding pipeline wherein at any given stage in the pipeline, while a given function is being performed on a given macroblock, the next macroblock in the data stream is being worked on by the previous function in the pipeline.

Abstract: The method of scalable coding of moving images using at least one reference image for at least one image to code, comprises, at least on passing, for a so-called “current” image, from an initial quality level to an intended quality level different from the initial quality level: a step (705) of coding the current image as far as the intended quality level to provide a coded current image, a step (710) of reconstructing the current image at the intended quality level to provide a reconstructed current image of intended quality level, a step (715) of obtaining at least one reference image of the current image at the initial quality level, to provide a prediction image for the initial quality level, a step (720, 725) of determining a differential texture refinement depending on the prediction image for the initial quality level and on the reconstructed current image of intended quality level and a step (730) of coding the differential texture refinement.

Abstract: A system is configured to transcode a first MPEG stream to a second MPEG stream. The system includes a first MPEG decoder capable of decoding the first MPEG stream and a second MPEG encoder capable of producing the second MPEG stream. The second MPEG encoder is configured to maintain a decoded picture type of I, P, or B. The second MPEG encoder is also configured to maintain a decoded picture structure of frame or field, identify a metadata per each macroblock (MB) of an MB pair of the first MPEG stream, and determine whether to re-encode the MB into the second MPEG stream using one of a frame or a field mode based on the identified metadata. The second MPEG encoder is further configured to re-encode the MB pair into the second MPEG stream using one of the frame or the field mode based on the identified metadata.

Abstract: A visual dynamic range (VDR) signal and a standard dynamic range (SDR) signal are received. A first (e.g., MPEG-2) encoder encodes a base layer (BL) signal. A second encoder encodes an enhancement layer (EL). The EL signal represents information with which the VDR signal may be reconstructed, e.g., using the BL and the EL signals. The first encoder encodes the SDR signal with inverse discrete cosine transform (IDCT) coefficients that have a fixed precision, e.g., which represent fixed-point approximations of transform coefficients that may have arbitrary precisions. The BL signal is encoded in a stream that conforms with an Advanced Television Standards Committee (ATSC) standard. The EL is encoded in a stream that conforms with an ATSC enhanced vestigial sideband (E-VSB) standard. The BL and EL signals are combined; e.g., multiplexed, and transmitted together.

Abstract: This disclosure presents techniques for implementing a fast algorithm for implementing odd-type DCTs and DSTs. The techniques include the computation of an odd-type transform on any real-valued sequence of data (e.g., residual values in a video coding process or a block of pixel values of an image coding process) by mapping the odd-type transform to a discrete Fourier transform (DFT). The techniques include a mapping between the real-valued data sequence to an intermediate sequence to be used as an input to a DFT. Using this intermediate sequence, an odd-type transform may be achieved by calculating a DFT of odd size.

Abstract: A method and system for image and video encoding and decoding is disclosed. A plurality of macro-blocks of pixels are defined in the image to be encoded, for subsequent block-by-block encoding and decoding. A node-cell structure of pixels is individually defined for each macro-block. The node pixels are encoded first. Then, the cell pixels are encoded using the decoded node pixels as a reference. This allows increasing macro-block size without a significant degradation of pixel encoding quality.

Abstract: A method for decoding an encoded video bit stream in a video decoder is provided that includes determining a scan pattern type for a transform block to be decoded, decoding a column position X and a row position Y of a last non-zero coefficient in the transform block from the encoded video bit stream, selecting a column-row inverse transform order when the scan pattern type is a first type, selecting a row-column inverse transform order when the scan pattern type is a second type, and performing one dimensional (1D) inverse discrete cosine transformation (IDCT) computations according to the selected transform order to inversely transform the transform block to generate a residual block.

Abstract: An image encoding method for encoding an image in an image encoding apparatus. The encoding process includes performing, in a quantization unit in the image encoding apparatus, quantization on a chroma component of transform coefficients using a chroma quantization parameter calculated on the basis of a luma quantization parameter weighted by an addition operation that adds a weight parameter; and encoding, in an encoding unit in the image encoding apparatus, a chroma component of quantized coefficients.

Abstract: In one embodiment of the invention, decompressed video signals are upscaled and then filtered using a combined mosquito noise reduction (MNR) and aliasing coring filter that reduces both mosquito noise in the decompressed video signals as well as aliasing noise resulting from the upscaling process. In one implementation, the combined coring filter includes a dual-band filter having two passbands interleaved with two stopbands. The strength of the coring filter may be dynamically controlled based on compression information (e.g., quantizer scales indicative of video quality) associated with the compressed video bitstream from which the decompressed video is recovered.

Abstract: Techniques are described to signal a maximum dynamic range of inverse discrete cosine transform (“IDCT”) output values that may be produced when a set of encoded media data is decoded. In accordance with these techniques, an encoding device may generate a media file that includes encoded media data associated with a set of one or more video frames. The media file may also include a range indication element that indicates the maximum dynamic range of IDCT output values produced when the encoded media data is decoded. A decoding device that receives the media file may, prior to decoding the encoded media data, use the range indication element to determine whether to decode the encoded media data. For instance, the decoding device may not decode the encoded media data when the decoding device is not capable of producing IDCT output values in the indicated range of IDCT output values.

Abstract: The invention relates to a method for coding a sequence of images divided into blocks, comprising the following steps for a current block:—selecting, for the current block, a coding mode in a set of coding modes that comprises at least two coding modes, and a transform in a set of transforms that comprises at least a first transform and a second transform; and—coding the current block according to the coding mode and the transform selected. The coding mode and the transform, themselves, are selected according to the following steps:—selecting the coding mode in the set of coding modes while using the first transform, and—selecting the transform in the set of transforms while using the coding mode selected.

Abstract: A method and system are disclosed for selecting a mode to encode video data. The method comprises the steps of (a) transforming a source video frame into a set of coefficients, (b) partitioning said set of coefficients into a plurality of subsets of the coefficients on the basis of probability statistics corresponding to a plurality of encoding modes, wherein each of said subsets is identified for encoding by one of the plurality of encoding modes. The method comprises the further steps of (c) for each of the plurality of subsets of coefficients, computing defined parameters of an associated probability distribution for said subset, and (d) repeating steps (b) and (c) until a predetermined termination condition is satisfied. When this predetermined termination condition is satisfied, the subsets of coefficients, as they exist at that time, are output to a video encoder, which preferably is a Wyner-Ziv encoder.

Abstract: A method and a system for adaptively (dynamically) reducing quantization layer reduction for removing quantization artifacts in quantized video signals is provided. Adaptively reducing quantization layer reduction involves detecting if a selected pixel in a quantized image belongs to a ramp area in each of multiple pre-defined directions, dynamically selecting a quantization level for each of the pre-defined directions based on the corresponding detection results, and refining the pixel based on the selected quantization levels.

Abstract: A discrete cosine transform (DCT) and inverse discrete cosine transform (IDCT) circuit includes a microcode memory, a processor, and a butterfly operation circuit. The microcode memory stores multiple microcode groups corresponding to DCT/IDCT operations and each of the microcode groups includes a series of microcodes. The processor obtains one of the microcode groups corresponding to one of the DCT/IDCT operations to be performed and retrieves microcodes in the obtained microcode group in sequence. The butterfly operation circuit performs butterfly operations according to the retrieved microcodes to execute one of the DCT/IDCT operations.