Mediatek Corporation

Min-Hao Chiu

Yung-Chang Chang

Chia-Yun Cheng

Chia-yun Cheng

Chun-Chia Chen

Chih-Ming Wang

Yen-Chieh Huang

Yu-Chuan Wang

Hsiu-Yi Lin

Yueh-Lin Wu

Ming-Hsien Lai

Chi-Min Chen

A video decoding method includes: before residual decoding of a coding unit is completed, referring to available information to determine whether to decode information that an inverse transform (IT) circuit needs for applying inverse transform to transform blocks of the coding unit, and generating a determination result; and controlling coefficient transmission of the coding unit to the IT circuit according to the determination result.

Method and apparatus for contorlling coefficient transmission by early determining whether to decode information that inverse transform needs

Various schemes for realizing efficient in-loop filtering are described, manifested in low latency and reduced hardware cost for an in-loop filter comprising at least two filtering stages. An apparatus receives pixel data of a current block of a picture and one or more neighboring blocks thereof, based on which the apparatus performs a filtering operation and generates a filtered block that includes completely filtered sub-blocks and partially filtered sub-blocks. The apparatus further outputs an output block that includes the completely filtered sub-blocks as well as a respective portion of each of the partially filtered sub-blocks, wherein the respective portion is adjacent to one of the completely filtered sub-blocks.

Efficient in-loop filtering for video coding

A method and apparatus for video encoding or decoding used by a video encoder or decoder respectively. In one method, input data associated with a video sequence are received. A current sequence header for a current picture is determined. Whether the current sequence header corresponds to a first sequence header or a second sequence header is determined. If the current sequence header corresponds to the second sequence header, one or more syntax values of a syntax set associated with the first sequence header are assigned to corresponding one or more syntax values of the syntax set associated with the current sequence header. The current picture is then encoded or decoded according to the current sequence header.

Method and apparatus of constrained sequence header

A decoding apparatus is used for decoding region of interest (ROI) regions in an image, and includes a storage device, a pre-processing circuit, a decoding circuit, and an information fetching circuit. The pre-processing circuit performs a syntax pre-parsing operation upon a bitstream to obtain necessary information of the ROI regions, and stores the necessary information into the storage device. The decoding circuit performs a decoding operation upon the bitstream to decode the ROI regions, wherein the decoding operation includes syntax parsing of the bitstream. The information fetching circuit reads and analyzes the necessary information, and delivers at least a portion of the necessary information to the decoding circuit. A processing time of obtaining necessary information of one ROI region at the pre-processing circuit overlaps a processing time of decoding another ROI region at the decoding circuit.

Apparatus and method for decoding ROI regions in image

A palette decoding apparatus includes a palette color storage device which stores palette colors, a color index storage device which stores color indices of pixels, and a palette value processing circuit which generates a palette value for each pixel by reading data from the color index storage device and the palette color storage device. A frame is divided into first coding units, and each first coding unit is sub-divided into one or more second coding units. Before a palette value of a last pixel in a first coding unit is generated by the palette value processing circuit, a palette value of a non-last pixel in the first coding unit is generated by the palette value processing circuit and used by a reconstruction circuit of the video decoder.

Apparatus and method for palette decoding

A method and apparatus for video encoding or decoding used by an AVS2 (Second Generation of Audio Video Coding Standard) video encoder or decoder respectively are disclosed. According to this method, first motion vectors associated with spatial neighboring blocks of a current block are determined. For each spatial neighboring block, a value of 1 is assigned to a first BlockDistance associated with the spatial neighboring block if a corresponding first reference picture is a G picture or GB picture. Motion vector predictor candidates are derived from the first motion vectors by scaling each first motion vector according to a corresponding first BlockDistance and a current BlockDistance. A final motion vector predictor is determined among the motion vector predictor candidates. The current motion vector is encoded or decoded using the final motion vector predictor

Method and apparatus of motion vector prediction

A residual up-sampling apparatus has a residual up-sampling buffer and a shared residual up-sampling circuit. The residual up-sampling buffer stores an intermediate residual up-sampling result. The shared residual up-sampling circuit employs a same processing kernel to perform a first-direction residual up-sampling operation and a second-direction residual up-sampling operation. The first-direction residual up-sampling operation processes an inverse transform output of an inverse transform circuit to generate the intermediate residual up-sampling result to the residual up-sampling buffer. The second-direction residual up-sampling operation performs transpose access upon the residual up-sampling buffer to retrieve the intermediate residual up-sampling result, and processes the intermediate residual up-sampling result to generate a final residual up-sampling result.

Residual up-sampling apparatus for performing transform block up-sampling and residual down-sampling apparatus for performing transform block down-sampling

A residual processing circuit has a single-path pipeline and a single-path controller. The single-path pipeline has an inverse scan (IS) circuit, an inverse quantization (IQ) circuit and an inverse transform (IT) circuit arranged to process a current non-zero residual data block in a pipeline manner. The current non-zero residual data block is at least a portion of a transform unit. The single-path controller controls pipelined processing of the current non-zero residual data block at the single-path pipeline. The single-path controller instructs the IS circuit to start IS processing of a next non-zero residual data block before the IT circuit finishes a first half of IT processing of the current non-zero residual data block.

Residual processing circuit using single-path pipeline or multi-path pipeline and associated residual processing method

A partial decoding circuit with inverse second transform has a transpose buffer, a first-direction inverse residual transform circuit, and a second-direction inverse residual transform circuit. The transpose buffer stores an intermediate inverse residual transform result. The first-direction inverse residual transform circuit processes an inverse quantization output to generate the intermediate inverse residual transform result to the transpose buffer. The second-direction inverse residual transform circuit accesses the transpose buffer to retrieve the intermediate inverse residual transform result, and processes the intermediate inverse residual transform result to generate a final inverse residual transform result, where the final inverse residual transform result of the inverse second transform is further processed by an inverse transform circuit. The first-direction inverse residual transform circuit and the second-direction inverse residual transform circuit process partial residual transform data of different process units in a parallel processing manner.

Partial decoding circuit of video encoder/decoder for dealing with inverse second transform and partial encoding circuit of video encoder for dealing with second transform

A video decoder has a first processing circuit and a second processing circuit. A shared storage device is accessible to the first processing circuit and the second processing circuit. The first processing circuit performs a first decoding operation according to data access of the shared storage device. The second processing circuit performs a second decoding operation according to data access of the shared storage device. The first decoding operation is at least a portion of a first decoding function complying with a first video coding standard, and the second decoding operation is at least a portion of a second decoding function complying with a second video coding standard different from the first video coding standard.

Video decoder and video encoder using storage sharing technique for performing decoding and encoding functions complying with different video coding standards and associated shared storage device

An exemplary video decoding apparatus includes a first decoding unit configured for decoding a first encoded block to generate first residual values, a first detecting unit configured for detecting whether all of the first residual values have a same first value, a first processing circuit configured for processing the first residual values to generate first processed residual values, and a second processing circuit configured for generating a decoded block corresponding to the first encoded block. When all of the first residual values have the same first value, the first detecting unit controls the second processing circuit to generate the decoded block without referring to the first processed residual values.

Video decoding apparatus and method for selectively bypassing processing of residual values and/or buffering of processed residual values

A method and apparatus for decoding two-level scanned transform coefficients corresponding to a transform unit (TU) are disclosed. The TU is divided into sub-blocks and the transform coefficients of the TU are scanned across the sub-blocks according to a first scan pattern, and each sub-block is scanned according to a second scan pattern. In one embodiment, the sub-blocks of the transform coefficients received from the variable length decoding are stored in an inverse scan buffer (or TC buffer) and the transform coefficients are retrieved from the inverse scan buffer row-by-row or column-by-column in a selected direction after a corresponding row or column of the transform coefficients is fully received. In a system incorporating an embodiment of the present invention, at least a leading row or a leading column of the transform coefficients is available in the selected direction before a last sub-block of the transform coefficients arrives.

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Hsinchu, Taiwan

Min-Hao Chiu