METHOD AND SYSTEM FOR PROCESSING VIDEO CONTENT

1 . A computer-implemented video processing method, comprising:

decoding or encoding a bitstream comprising coded information representing a plurality of luma samples; and

reconstructing a chroma block based on the plurality of luma samples,

wherein reconstructing the chroma block comprises:

determining whether a transform unit has non-zero chroma residuals; and

in response to a determination that the transform unit has no non-zero chroma residuals, bypassing a process of averaging the plurality of luma samples, wherein the process of averaging is used for scaling chroma residuals of the transform unit.

2 . The method according to claim 1 , wherein reconstructing the chroma block further comprises:

in response to a determination that the transform unit has one or more non-zero chroma residuals, performing the process of averaging to determine an averaged value of the plurality of luma samples, scaling the one or more non-zero chroma residuals based on the averaged value, and reconstructing the chroma block based on the scaled one or more non-zero chroma residuals.

3 . The method according to claim 2 , where scaling the one or more non-zero chroma residuals based on the averaged value of the plurality of luma samples comprises:

determining a chroma scaling factor based on the averaged value; and

applying the chroma scaling factor to the one or more non-zero chroma residuals.

4 . The method according to claim 1 , wherein whether the transform unit has no non-zero chroma residuals is determined based on a value of a coded flag associated with the transform unit.

5 . The method according to claim 4 , further comprising:

in response to the value of the coded flag being equal to 1, determining that the transform unit has one or more non-zero chroma residuals.

6 . The method according to claim 4 , further comprising:

in response to the value of the coded flag being equal to 0, determining that the transform unit has no non-zero chroma residuals.

7 . The method according to claim 1 , wherein whether the transform unit has no non-zero chroma residuals is determined based on:

a value of a first coded flag associated with a first chroma component of the transform unit, and

a value of a second coded flag associated with a second chroma component of the transform unit.

8 . The method according to claim 7 , further comprising:

in response to at least one of the value of the first coded flag or the value of the second coded flag being equal to 1, determining that the transform unit has one or more non-zero chroma residuals.

9 . The method according to claim 7 , further comprising:

in response to both the value of the first coded flag and the value of the second coded flag being equal to 0, determining that the transform unit has no non-zero chroma residuals.

10 . An apparatus, comprising:

one or more memories storing a set of instructions; and

one or more processors configured to execute the set of instructions to cause the apparatus to perform:

decoding or encoding a bitstream comprising coded information representing a plurality of luma samples; and

reconstructing a chroma block based on the plurality of luma samples,

wherein in reconstructing the chroma block, the one or more processors are configured to execute the set of instructions to cause the apparatus to further perform:

determining whether a transform unit has non-zero chroma residuals; and

in response to a determination that the transform unit has no non-zero chroma residuals, bypassing a process of averaging the plurality of luma samples, wherein the process of averaging is used for scaling chroma residuals of the transform unit.

11 . The apparatus according to claim 10 , wherein the one or more processors are configured to execute the set of instructions to cause the apparatus to further perform:

in response to a determination that the transform unit has one or more non-zero chroma residuals, performing the process of averaging to determine an averaged value of the plurality of luma samples, scaling the one or more non-zero chroma residuals based on the averaged value, and reconstructing the chroma block based on the scaled one or more non-zero chroma residuals.

12 . The apparatus according to claim 11 , wherein the one or more processors are configured to execute the set of instructions to cause the apparatus to further perform:

determining a chroma scaling factor based on the averaged value of the plurality of luma samples; and

applying the chroma scaling factor to the one or more non-zero chroma residuals.

13 . The apparatus according to claim 10 , wherein the one or more processors are configured to execute the set of instructions to cause the apparatus to further perform:

determining whether the transform unit has no non-zero chroma residuals, based on a value of a coded flag associated with the transform unit.

14 . The apparatus according to claim 13 , wherein the one or more processors are configured to execute the set of instructions to cause the apparatus to further perform:

in response to the value of the coded flag being equal to 1, determining that the transform unit has one or more non-zero chroma residuals.

15 . The apparatus according to claim 13 , wherein the one or more processors are configured to execute the set of instructions to cause the apparatus to further perform:

in response to the value of the coded flag being equal to 0, determining that the transform unit has no non-zero chroma residuals.

16 . A method of storing a bitstream of a video, the method comprising:

reconstructing a chroma block based on a plurality of luma samples associated with the chroma block;

generating a bitstream comprising coded information for reconstructing the chroma block; and

storing the bitstream in a non-transitory computer readable medium,

wherein reconstructing the chroma block comprises:

determining whether a transform unit has non-zero chroma residuals; and

in response to a determination that the chroma block has no non-zero chroma residuals, bypassing a process of averaging the plurality of luma samples, wherein the process of averaging is used for scaling chroma residuals of the transform unit.

17 . The method according to claim 16 , further comprising:

in response to a determination that the transform unit has one or more non-zero chroma residuals, performing the process of averaging to determine an averaged value of the plurality of luma samples, scaling the one or more non-zero chroma residuals based on the averaged value, and reconstructing the chroma block based on the scaled one or more non-zero chroma residuals.

18 . The method according to claim 17 , where scaling the one or more non-zero chroma residuals based on the averaged value comprises:

determining a chroma scaling factor based on the averaged value; and

applying the chroma scaling factor to the one or more non-zero chroma residuals.

19 . The method of claim 16 , wherein the bitstream comprises a coded flag indicating whether the chroma block has no non-zero chroma residuals.

20 . The method of claim 16 , wherein the bitstream comprises:

a first coded flag associated with a first chroma component of the chroma block, and

a second coded flag associated with a second chroma component of the chroma block, wherein:

when at least one of a value of the first coded flag or a value of the second coded flag is equal to 1, it is indicated that the chroma block has one or more non-zero chroma residuals; and

when both the value of the first coded flag and the value of the second coded flag are equal to 0, it is indicated that the chroma block has no non-zero chroma residuals.