Systems and methods for reference offset signaling in video coding
View Patent ↗A method of deriving prediction sample values for decoding video data by a device is provided. A reference wraparound offset syntax specifying an offset used for computing a horizontal wrap-around position is decoded. A luma location is derived based on a product of a value of the reference wraparound offset syntax and a minimum coding block size. A predicted luma sample value is derived by using the luma location.
1. A method of deriving prediction sample values for decoding video data, the method comprising:
decoding a reference wraparound offset syntax specifying an offset used for computing a horizontal wrap-around position, wherein a maximum value of the reference wraparound offset syntax is determined based on a quotient obtained by dividing a width of each decoded picture by a minimum coding block size;
deriving a luma location based on a product of a value of the reference wraparound offset syntax and the minimum coding block size; and
deriving a predicted luma sample value by using the luma location.
2. The method of claim 1 , wherein the luma location is derived for a luma sample bilinear interpolation process.
3. The method of claim 1 , further comprising:
setting an offset variable equal to a value obtained by dividing the product of the value of the reference wraparound offset syntax and the minimum coding block size by a width value; and
deriving a chroma location by using the offset variable,
wherein the width value is specified based on a chroma format.
4. The method of claim 3 , wherein the chroma format includes one of a 4:2:0 format, a 4:2:2 format and a 4:4:4 format.
5. A method of deriving prediction sample values for encoding data, the method comprising:
encoding a reference wraparound offset syntax specifying an offset used for computing a horizontal wrap-around position, wherein a maximum value of the reference wraparound offset syntax is determined based on a quotient obtained by dividing a width of each decoded picture by a minimum coding block size;
deriving a luma location based on a product of a value of the reference wraparound offset syntax and the minimum coding block size; and
deriving a predicted luma sample value by using the luma location.
6. A device for deriving prediction sample values for decoding video data, the device comprising:
one or more processors; and
a storage device coupled to the one or more processors and storing a program which, when executed by the one or more processors, causes the device to:
decode a reference wraparound offset syntax specifying an offset used for computing a horizontal wrap-around position, wherein a maximum value of the reference wraparound offset syntax is determined based on a quotient obtained by dividing a width of each decoded picture by a minimum coding block size;
derive a luma location based on a product of a value of the reference wraparound offset syntax and the minimum coding block size; and
derive a predicted luma sample value by using the luma location.
7. The method of claim 1 , wherein the maximum value of the reference wraparound offset syntax is further determined by subtracting a positive number from the quotient.
8. The method of claim 5 , wherein the luma location is derived for a luma sample bilinear interpolation process.
9. The method of claim 5 , further comprising:
setting an offset variable equal to a value obtained by dividing the product of the value of the reference wraparound offset syntax and the minimum coding block size by a width value; and
deriving a chroma location by using the offset variable,
wherein the width value is specified based on a chroma format.
10. The method of claim 9 , wherein the chroma format includes one of a 4:2:0 format, a 4:2:2 format and a 4:4:4 format.
11. The method of claim 5 , wherein the maximum value of the reference wraparound offset syntax is further determined by subtracting a positive number from the quotient.
12. The device of claim 6 , wherein the luma location is derived for a luma sample bilinear interpolation process.
13. The device of claim 6 , further comprising:
setting an offset variable equal to a value obtained by dividing the product of the value of the reference wraparound offset syntax and the minimum coding block size by a width value; and
deriving a chroma location by using the offset variable,
wherein the width value is specified based on a chroma format.
14. The device of claim 13 , wherein the chroma format includes one of a 4:2:0 format, a 4:2:2 format and a 4:4:4 format.
15. The device of claim 6 , wherein the maximum value of the reference wraparound offset syntax is further determined by subtracting a positive number from the quotient.