Patent application number | Description | Published |
20130235940 | METHODS AND DEVICES FOR CONTEXT MODELING TO ENABLE MODULAR PROCESSING - Methods of encoding and decoding for video data are described for encoding or decoding coefficients for a transform unit. In particular, the significant-coefficient flags for a coefficient group are encoded and decoded based upon a context determination, and the context is determined based upon the values of neighboring flags. The neighborhood used to determine the context varies depending on whether the significant-coefficient flag to be encoded or decoded is in the right column or bottom row of the coefficient group or not. If it is in the right column or bottom row one of the alternative context neighborhoods is used to avoid relying on significant-coefficient flags in other coefficient groups except for the flags immediately adjacent the right border and bottom border of the coefficient group, and the flag diagonally to the lower-right. | 09-12-2013 |
20140003488 | POSITION-BASED CONTEXT SELECTION FOR GREATER-THAN-ONE FLAG DECODING AND ENCODING | 01-02-2014 |
20140064364 | METHODS AND DEVICES FOR INTER-LAYER PREDICTION IN SCALABLE VIDEO COMPRESSION - Methods and devices for encoding and decoding scalable video are described. In one aspect, a method of reconstructing, in a video decoder, an enhancement-layer image based upon a reconstructed reference-layer image using inter-layer prediction is described. The method includes reconstructing a reference-layer residual and a reference-layer prediction, wherein the reference-layer residual and the reference-layer prediction, when combined, form the reconstructed reference-layer image; up-sampling the reference-layer residual using a first up-sampling operation; up-sampling the reference-layer prediction using a second up-sampling operation different from the first up-sampling operation; generating an inter-layer prediction using the up-sampled reference-layer residual and the up-sampled reference-layer prediction; and reconstructing the enhancement-layer image based upon the inter-layer prediction. | 03-06-2014 |
20140064365 | METHODS AND DEVICES FOR ENTROPY CODING IN SCALABLE VIDEO COMPRESSION - Methods and devices for decoding, in a video decoder, a block of enhancement-layer transform domain data for an enhancement-layer encoded video and corresponding to a reconstructed block of reference-layer transform domain data, are provided. The method includes determining a context for an enhancement-layer element based, at least in part, upon elements in the corresponding reconstructed block of reference-layer transform domain data, wherein the elements are identified by a template and wherein the position of the template in the reference-layer reconstructed block is based upon the position of that enhancement-layer element in the block of enhancement-layer transform domain data. | 03-06-2014 |
20150078432 | CODING POSITION DATA FOR THE LAST NON-ZERO TRANSFORM COEFFICIENT IN A COEFFICIENT GROUP - Methods and devices for video coding are described. When encoding a non-zero coefficient group (CG) prior to the last such group in a group scan ordering within a transform block, data representative of the true (x,y)-position of the last non-zero transform coefficient in a scan ordering within that CG is modified, to improve coding efficiency, based upon at least one of (a) an intra-prediction mode used to encode the block and (b) at least one coefficient group neighbouring that CG. Upon decoding a CG thus encoded, the modification is un-done to retrieve the true (x,y)-position. | 03-19-2015 |
20150078445 | TRANSPOSING A BLOCK OF TRANSFORM COEFFICIENTS, BASED UPON AN INTRA-PREDICTION MODE - Methods and devices for video coding are described. If an intra-prediction mode to be used in encoding a block of residual data is in a specific predetermined class, e.g., the horizontal class, then at least a portion of a quantized transformed block of residual data is transposed during encoding. Likewise, if an intra-prediction mode that was used to generate an encoded block of residual data is in such a class, then at least a portion of an entropy-decoded block of residual data is transposed during decoding. | 03-19-2015 |
20150189280 | MULTI-LEVEL SIGNIFICANCE MAPS FOR ENCODING AND DECODING - Methods of encoding and decoding for video data are described in which multi-level significance maps are used in the encoding and decoding processes. The significant-coefficient flags that form the significance map are grouped into contiguous groups, and a significant-coefficient-group flag signifies for each group whether that group contains no non-zero significant-coefficient flags. If there are no non-zero significant-coefficient flags in the group, then the significant-coefficient-group flag is set to zero. The set of significant-coefficient-group flags is encoded in the bitstream. Any significant-coefficient flags that fall within a group that has a significant-coefficient-group flag that is non-zero are encoded in the bitstream, whereas significant-coefficient flags that fall within a group that has a significant-coefficient-group flag that is zero are not encoded in the bitstream. | 07-02-2015 |
20150334425 | ADAPTIVE CONTEXT INITIALIZATION - Methods of encoding and decoding video are described. The encoder and decoder include a buffer storing at least two context model states, each being the context model state after context-adaptive encoding/decoding of a respective previously-encoded/decoded picture. One of the at least two stored context model states is selected from the buffer and used to initialize the context model for context-adaptively decoding a current picture. The current picture is then context-adaptively entropy encoding/decoded. | 11-19-2015 |