Device and method for coding video data based on one or more reference lines

Patent metadata

Field	Value
Publication number	US-2020007879-A1
Application number	US-201916453580-A
Country	US
Kind code	A1
Filing date	Jun 26, 2019
Priority date	Jun 29, 2018
Publication date	Jan 2, 2020
Grant date	—

Abstract

A method of decoding a bitstream by an electronic device is provided. A block unit having a block size is determined from an image frame according to the bitstream. The number of one or more reference lines neighboring to the block unit is determined based on the block size. One of the one or more reference lines is selected based on the number of the one or more reference lines. The block unit is reconstructed based on the selected one of the one or more reference lines.

First claim

What is claimed is:

1 . A method of decoding a bitstream by an electronic device, the method comprising:
determining a block size of a block unit from an image frame according to the bitstream; determining a number of one or more reference lines based on the block size; selecting one of the one or more reference lines based on the number of the one or more reference lines; and reconstructing the block unit based on the selected one of the one or more reference lines.

2 . The method according to claim 1 , further comprising:
determining the selected one of the one or more reference lines based on a line index, when the number of the one or more reference lines is greater than one; and setting the one or more reference lines as the selected one of the one or more reference lines, when the number of the one or more reference lines is equal to one.

3 . The method according to claim 1 , wherein a prediction mode of the block unit is selected from a plurality of mode candidates based on a mode flag and a mode index, when the selected one of the one or more reference lines is identical to a first one of the one or more reference lines and adjacent to the block unit.

4 . The method according to claim 3 , wherein the plurality of mode candidates is categorized into a most probable mode (MPM) list and a non-MPM list, and the mode flag indicates which one of the MPM list and the non-MPM list the prediction mode is included.

5 . The method according to claim 4 , wherein the prediction mode is selected based on the mode index from the MPM list without parsing the mode flag, when the selected one of the one or more reference lines is different from the first one of the one or more reference lines.

6 . The method according to claim 1 , wherein the number of the one or more reference lines is determined based on a size comparison generated based on the block size and a size threshold.

7 . The method according to claim 6 , further comprising:
determining the number of the one or more reference lines as a predefined quantity greater than one, when the size comparison satisfies a predefined condition; and determining the number of the one or more reference lines as one, when the size comparison does not satisfy the predefined condition.

8 . The method according to claim 7 , wherein the predefined condition includes at least one of a first condition that the block size is less than a first threshold, a second condition that the block size is greater than a second threshold different from the first threshold, a third condition that a size ratio determined based on a block width and a block height of the block size is less than a third threshold, and a fourth condition that the size ratio is equal to a fourth threshold different from the third threshold.

9 . An electronic device for decoding a bitstream, the electronic device comprising:
at least one processor; and a storage device coupled to the at least one processor and storing a plurality of instructions which, when executed by the at least one processor, causes the at least one processor to:
determine a block size of a block unit from an image frame according to the bitstream;
determine a number of one or more reference lines based on the block size;
select one of the one or more reference lines based on the number of the one or more reference lines; and
reconstruct the block unit based on the selected one of the one or more reference lines.

10 . The electronic device according to claim 9 , wherein the plurality of instructions, when executed by the at least one processor, further causes the at least one processor to:
determine the selected one of the one or more reference lines based on a line index, when the number of the one or more reference lines is greater than one; and set the one or more reference lines as the selected one of the one or more reference lines, when the number of the one or more reference lines is equal to one.

11 . The electronic device according to claim 9 , wherein a prediction mode of the block unit is selected from a plurality of mode candidates, when the selected one of the one or more reference lines is identical to a first one of the one or more reference lines and adjacent to the block unit.

12 . The electronic device according to claim 11 , wherein the prediction mode is selected from a plurality of most probable modes determined from the plurality of mode candidates, when the selected one of the one or more reference lines is different from the first one of the one or more reference lines.

13 . The electronic device according to claim 9 , wherein the plurality of instructions, when executed by the at least one processor, further causes the at least one processor to:
determine the number of the one or more reference lines as a predefined quantity greater than one, when a size comparison determined based on the block size and a size threshold satisfies a predefined condition; and determine the number of the one or more reference lines as one, when the size comparison does not satisfy the predefined condition.

14 . The electronic device according to claim 13 , wherein the predefined condition includes at least one of a first condition that the block size is less than a first threshold, a second condition that the block size is greater than a second threshold different from the first threshold, a third condition that a size ratio determined based on a block width and a block height of the block size is less than a third threshold, and a fourth condition that the size ratio is equal to a fourth threshold different from the third threshold.

15 . A method of decoding a bitstream by an electronic device, the method comprising:
determining a block width and a block height of a block unit from an image frame according to the bitstream; determining a number of one or more reference lines based on the block width and the block height; set the one or more reference lines as a prediction line, when the number of the one or more reference lines is equal to one; select the prediction line from the one or more reference lines based on a line index, when the number of the one or more reference lines is greater than one; and reconstructing the block unit based on the prediction line.

16 . The method according to claim 15 , wherein a prediction mode of the block unit is selected based on a mode index from one of a most probable mode (MPM) list and a non-MPM list selected based a mode flag, when the prediction line is identical to a first one of the one or more reference lines and adjacent to the block unit.

17 . The method according to claim 16 , wherein the prediction mode is selected based on the mode index directly from the MPM list without parsing the mode flag, when the prediction line is different from the first one of the one or more reference lines.

18 . The method according to claim 15 , wherein the number of the one or more reference lines is determined based on a size comparison determined based on the block width and the block height and a size threshold.

19 . The method according to claim 18 , further comprising:
determining the number of the one or more reference lines as a predefined quantity greater than one, when the size comparison satisfies a predefined condition; and determining the number of the one or more reference lines as one, when the comparison does not satisfy the predefined condition.

20 . The method according to claim 19 , wherein the predefined condition includes at least

Assignees

• Fg innovation co ltd

Inventors

• Jiang Hui-Yu
• Chang Yao-Jen

Classifications

• H04N19/11 Primary

  among a plurality of spatial predictive coding modes · CPC title

• H04N19/105 Primary

  Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction · CPC title

• H04N19/46

  Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) · CPC title

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title

• H04N19/44 Primary

  Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder · CPC title