Shift based cross-component adaptive loop filter
A method, computer program, and computer system is provided for video coding. Video data comprising a chroma component and a luma component is received. Luma samples are extracted from the luma component of the received video data. The chroma component is filtered based on the extracted luma samples using a cross-component adaptive loop filter (CC-ALF). Coefficients associated with the CC-ALF are constrained to be less than a sum of a bit-depth value associated with the luma samples and a positive offset value.
1. A method of coding video data, executable by a processor, comprising:
receiving video data comprising a chroma component and a luma component;
extracting luma samples from the luma component;
filtering the chroma component based on the extracted luma samples using a cross-component adaptive loop filter (CC-ALF), wherein coefficients associated with the CC-ALF are constrained to be less than a sum of a bit-depth value associated with the luma samples and a positive offset value; and
constraining a number of the coefficients to no more than 2 n , wherein a sum of the bit-depth value associated with the luma samples, the positive offset value, and n is less than or equal to sixteen.
2. The method of claim 1 , wherein the sum of the bit-depth value associated with the luma samples and the positive offset value is less than or equal to sixteen.
3. The method of claim 2 , wherein the bit-depth value is ten and the positive offset value is four.
4. The method of claim 2 , wherein the luma samples are right-shifted by a greater of zero and a difference of sixteen and the sum of the bit-depth value and the positive offset value.
5. The method of claim 1 , wherein the bit-depth value is eight, the positive offset value is four, n is four, and the number of coefficients is less than or equal to sixteen.
6. The method of claim 1 , wherein the luma samples are right-shifted by a greater of zero and a difference of sixteen and the sum of the bit-depth value, the positive offset value, and n.
7. A computer system for video coding, the computer system comprising:
one or more computer-readable non-transitory storage media configured to store computer program code; and
one or more computer processors configured to access said computer program code and operate as instructed by said computer program code, said computer program code including:
receiving code configured to cause the one or more computer processors to receive video data comprising a chroma component and a luma component;
extracting code configured to cause the one or more computer processors to extract luma samples from the luma component;
filtering code configured to cause the one or more computer processors to filter the chroma component based on the extracted luma samples using a cross-component adaptive loop filter (CC-ALF), wherein coefficients associated with the CC-ALF are constrained to be less than a sum of a bit-depth value associated with the luma samples and a positive offset value; and
constraining code configured to cause the one or more computer processors to constrain a number of the coefficients to no more than 2 n , wherein a sum of the bit-depth value associated with the luma samples, the positive offset value, and n is less than or equal to sixteen.
8. The computer system of claim 7 , wherein the sum of the bit-depth value associated with the luma samples and the positive offset value is less than or equal to sixteen.
9. The computer system of claim 8 , wherein the bit-depth value is ten and the positive offset value is four.
10. The computer system of claim 8 , wherein the luma samples are right-shifted by a greater of zero and a difference of sixteen and the sum of the bit-depth value and the positive offset value.
11. The computer system of claim 7 , wherein the bit-depth value is eight, the positive offset value is four, n is four, and the number of coefficients is less than or equal to sixteen.
12. The computer system of claim 7 , wherein the luma samples are right-shifted by a greater of zero and a difference of sixteen and the sum of the bit-depth value, the positive offset value, and n.
13. A non-transitory computer readable medium having stored thereon a computer program for video coding, the computer program configured to cause one or more computer processors to:
receive video data comprising a chroma component and a luma component;
extract luma samples from the luma component;
filter the chroma component based on the extracted luma samples using a cross-component adaptive loop filter (CC-ALF), wherein coefficients associated with the CC-ALF are constrained to be less than a sum of a bit-depth value associated with the luma samples and a positive offset value; and
constrain a number of the coefficients to no more than 2 n , wherein a sum of the bit-depth value associated with the luma samples, the positive offset value, and n is less than or equal to sixteen.
14. The computer readable medium of claim 13 , wherein the sum of the bit-depth value associated with the luma samples and the positive offset value is less than or equal to sixteen.
15. The computer readable medium of claim 14 , wherein the bit-depth value is ten and the positive offset value is four.
16. The computer readable medium of claim 14 , wherein the luma samples are right-shifted by a greater of zero and a difference of sixteen and the sum of the bit-depth value and the positive offset value.
17. The computer readable medium of claim 13 , wherein the bit-depth value is eight, the positive offset value is four, n is four, and the number of coefficients is less than or equal to sixteen.