Qualcomm Incorporated

Other

Wei Pu

Marta Karczewicz

Rajan Laxman Joshi

Joel Sole Rojals

Vadim Seregin

Feng Zou

Jianle Chen

Krishnakanth Rapaka

Xiang Yang Li

Liwei Guo

Woo-Shik Kim

Ye-Kui Wang

Cheng-Teh Hsieh

Chao Pang

Li Feng Zhang

In Suk Chong

In an example, a method of processing video data may include inferring a pixel scan order for a first palette mode encoded block of video data without receiving a block-level syntax element having a value representative of the pixel scan order for the first palette mode encoded block. The method may include decoding the first palette mode encoded block of video data using the inferred pixel scan order. The method may include receiving a block-level syntax element having a value representative of a pixel scan order for a second palette mode encoded block of video data. The method may include determining the pixel scan order for the second palette mode encoded block of video data based on the received block-level syntax element. The method may include decoding the second palette mode encoded block of video data using the determined pixel scan order.

Palette mode encoding and decoding design

Methods incorporating extensions to copy-above mode for palette mode coding are disclosed. In one aspect, the method includes coding a current pixel of a current block of video data in copy-previous mode via coding a previous line index. The coding of the current pixel in copy-previous mode further including identifying a number of candidate values for the previous line index, identifying a number of escape pixels in a column of pixels above the current pixel in the current block, and reducing a number of candidate values of the previous line index by the number of identified escape pixels.

Methods incorporating extensions to copy-above mode for palette mode coding

In an example a method of processing video data includes determining a first palette for a first block of video data that is located in a first row of blocks, generating a predictor palette for constructing at least one second palette of at least one second block of video data in the first row of blocks coded, reinitializing the predictor palette for determining a third palette of a third block of video data that is located in a second row of blocks, wherein re-initializing the predictor palette comprises re-initializing the predictor palette based on the one or more palette entries of the first palette or an initial predictor palette generated after coding the first block, determining the third palette of the third block based on the re-initialized predictor palette, and coding the third block using the third palette.

Predictor palette initialization in palette-based video coding

The method includes receiving video blocks that are each associated with a table having entries specifying pixel values used in the blocks. The method further includes dividing the blocks into sub-blocks each having an array of pixels. The method also includes selecting a sub-block scanning order that specifies an order in which the plurality of sub-blocks are to be encoded and a pixel scanning order that specifies an order in which the pixels of each sub-block are to be encoded. The scanning order and the pixel scanning order are selected based at least in part upon pixel value distributions and a bit rate for encoding the block according to the scanning or pixel scanning order, respectively. The blocks are then encoded using the selected scanning order and pixel scanning order and the index values in the table.

Methods and apparatus for encoding video data using block palettes and sub-block and pixel scanning orders

An example method of coding video data includes coding, from a coded video bitstream, a syntax element that indicates whether a transpose process is applied to palette indices of a palette for a current block of video data; decoding, from the coded video bitstream and at a position in the coded video bitstream that is after the syntax element that indicates whether the transpose process is applied to palette indices of the palette for the current block of video data, one or more syntax elements related to delta quantization parameter (QP) and/or chroma QP offsets for the current block of video data; and decoding the current block of video data based on the palette for the current block of video data and the one or more syntax elements related to delta QP and/or chroma QP offsets for the current block of video data.

Grouping palette bypass bins for video coding

In an example, a method of processing video data includes coding at least one of data that indicates a maximum palette size of a palette of color values for coding a block of video data or data that indicates a maximum palette predictor size of a palette predictor for determining the palette of color values. The method also includes coding the block of video data in accordance with the data.

Maximum palette parameters in palette-based video coding

In general, techniques are described for performing multiple passes of sample adaptive offset (SAO) filtering when coding video data. A video decoding device comprising one or more processors may perform the techniques. The processors may determine a first SAO pixel classification for a block of video data and determine a first offset value based on the first SAO pixel classification and one or more pixel values of the block. The one or more processors may also determine a second SAO pixel classification for the block and determine a second offset value based on the second SAO pixel classification and the one or more pixel values of block of video data. The processors may then apply the first offset value and the second offset value to the block of video data to generate a block of SAO filtered video data.

Multi-type parallelized sample adaptive offset in video coding

Palette mode encoding and decoding with inferred pixel scan order

A device for decoding video data is configured to determine, based on first entropy encoded data in the bitstream, a set of run-related syntax element groups for a current block of a current picture of the video data; determine, based on second entropy encoded data the bitstream, a set of palette index syntax elements for the current block, the first entropy encoded data occurring in the bitstream before the second entropy encoded data, wherein: each respective run-related syntax element group of the set of run-related syntax element groups indicates a respective type of a respective run of identical palette mode type indicators and a respective length of the respective run and each respective palette index syntax element of the set of palette index syntax elements indicates an entry in a palette comprising a set of sample values; and reconstruct, based on the sample values in the palette, the current block.

Grouping palette index at the end and index coding using palette size and run value

Methods and systems for video image coding are provided. Sets of filters may be selected and applied to video information at least partially based on phase displacement information between a first and second layer of video information. For example, the phase displacement information may correspond to a difference between a position of a pixel in the first layer and a corresponding position of the pixel in the second layer. The selected filter set can be an up-sampling filter or a down-sampling filter. The phase displacement information may be encoded as a syntax element embedded in the video bit stream.

Signaling of down-sampling location information in scalable video coding

In one example, a device includes a memory configured to store video data and a video decoder configured to decode an exponential Golomb codeword representative of at least a portion of a value for an escape pixel of a palette-mode coded block of video data, the video decoder is configured to decode the exponential Golomb codeword using exponential Golomb with parameter 3 decoding, and decode the block using the value for the escape pixel.

Coding escape pixels for palette coding

A method of decoding video data includes decoding a first block of video data to produce a block of reconstructed luma residual values and a block of predicted chroma residual values, wherein the block of video data has one of a 4:2:0 or a 4:2:2 chroma sub-sampling format. The method further includes performing a color residual prediction process to reconstruct a block of chroma residual values for the first block of video data using a subset of the reconstructed luma residual values as luma predictors for the block of predicted chroma residual values.

Color residual prediction for video coding

In an example a method of processing video data includes determining a run value that indicates a run-length of a run of a palette index of a block of video data, wherein the palette index is associated with a color value in a palette of color values for coding the block of video data, the method also includes determining a context for context adaptive coding of data that represents the run value based on the palette index, and coding the data that represents run value from a bitstream using the determined context.

Coding run values based on palette index in palette-based video coding

In palette-based coding, a video coder may form a so-called 'palette' as a table of colors representing the video data of a given block. The video coder may code index values for one or more pixels values of a current block of video data, where the index values indicate entries in the palette that represent the pixel values of the current block. A method includes determining a palette for a block of video data, identifying escape pixel(s) not associated with any palette entries, identifying a single quantization parameter (QP) value for all escape pixels of the block for a given color channel using a QP value for non-palette based coding of transform coefficients, dequantizing each escape pixel using the identified QP value, and determining pixel values of the block using the dequantized escape pixels and index values for any pixel(s) associated with any palette entries.

Color index coding for palette-based video coding

Techniques for encoding a binary prediction vector for predicting a palette for palette-based video coding is described. In one example, a method of decoding video comprises receiving an encoded binary prediction vector for a current block of video data, decoding the encoded binary prediction vector using a run-length decoding technique, generating a palette for the current block of video data based on the binary prediction vector, the binary prediction vector comprising entries indicating whether or not previously-used palette entries are reused for the palette for the current block of video data, and decoding the current block of video data using the palette.

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Wei Pu