Systems and methods for applying deblocking filters in video coding
This disclosure relates to video coding and more particularly to techniques for applying deblocking filters for coded video. In one example, a method of decoding chroma component parameter information for decoding video data comprises: receiving a picture parameter set (PPS) including syntax elements corresponding to a picture; parsing a flag in the PPS indicating whether chroma quantization parameter syntax elements are included in the PPS and whether chroma deblocking parameter syntax elements are included in the PPS; conditionally parsing the chroma quantization parameter syntax elements in the PPS based on the value of the flag; conditionally parsing the chroma deblocking parameter syntax elements in the PPS based on the value of the flag; deriving a quantization parameter based on the chroma quantization parameter syntax elements; and performing a deblocking filter based on the chroma deblocking parameter syntax elements.
1. A method of decoding chroma component parameter information for decoding video data, the method comprising:
receiving a picture parameter set;
parsing a first flag in the picture parameter set, wherein the first flag specifies whether chroma tool offsets related syntax elements, pps_cb_qp_offset and pps_cr_qp_offset, are present in the picture parameter set and whether chroma deblocking offset syntax elements, pps_cb_beta_offset_div2, pps_cb_tc_offset_div2, pps_cr_beta_offset_div2, and pps_cr_tc_offset_div2, are present in the picture parameter set;
conditionally parsing the chroma tool offsets related syntax elements in the picture parameter set based on a value of the first flag;
parsing a second flag in the picture parameter set, wherein the second flag is a deblocking filter override enabled flag and specifies whether deblocking behavior may be overridden at a picture level or at a slice level;
conditionally parsing a third flag in the picture parameter set based on a value of the second flag, wherein the third flag is a deblocking filter information in picture header flag and specifies whether deblocking filter information is present in a picture header syntax structure and not present in slice headers referring to the picture parameter set;
conditionally parsing the chroma deblocking offset syntax elements in the picture parameter set based on the value of the first flag;
deriving quantization parameters based on the chroma tool offsets related syntax elements; and
performing a deblocking filter based on the chroma deblocking offset syntax elements,
wherein the second flag and the third flag are ordered in the picture parameter set between the chroma tool offsets related syntax elements and the chroma deblocking offset syntax elements.
2. A device comprising one or more processors configured to:
receive a picture parameter set;
parse a first flag in the picture parameter set, wherein the first flag specifies whether chroma tool offsets related syntax elements, pps_cb_qp_offset and pps_cr_qp_offset, are present in the picture parameter set and whether chroma deblocking offset syntax elements, pps_cb_beta_offset_div2, pps_cb_tc_offset_div2, pps_cr_beta_offset_div2, and pps_cr_tc_offset_div2, are present in the picture parameter set;
conditionally parse the chroma tool offsets related syntax elements in the picture parameter set based on a value of the first flag;
parse a second flag in the picture parameter set, wherein the second flag is a deblocking filter override enabled flag and specifies whether deblocking behavior may be overridden at a picture level or at a slice level;
conditionally parse a third flag in the picture parameter set based on a value of the second flag, wherein the third flag is a deblocking filter information in picture header flag and specifies whether deblocking filter information is present in a picture header syntax structure and not present in slice headers referring to the picture parameter set;
conditionally parse the chroma deblocking offset syntax elements in the picture parameter set based on the value of the first flag;
derive quantization parameters based on the chroma tool offsets related syntax elements; and
perform a deblocking filter based on the chroma deblocking offset syntax elements,
wherein the second flag and the third flag are ordered in the picture parameter set between the chroma tool offsets related syntax elements and the chroma deblocking offset syntax elements.
3. The device of claim 2 , wherein the device includes a video decoder.
4. A device comprising one or more processors configured to:
signal a picture parameter set,
wherein the picture parameter set includes:
a first flag, wherein the first flag specifies whether chroma tool offsets related syntax elements, pps_cb_qp_offset and pps_cr_qp_offset, are present in the picture parameter set and whether chroma deblocking offset syntax elements are present in the picture parameter set, wherein the chroma tool offsets related syntax elements, pps_cb_beta_offset_div2, pps_cb_tc_offset_div2, pps_cr_beta_offset_div2, and pps_cr_tc_offset_div2, are conditionally parsed based on a value of the first flag,
a second flag, wherein the second flag is a deblocking filter override enabled flag and specifies whether deblocking behavior may be overridden at a picture level or at a slice level, and
a third flag that is conditionally parsed based on a value of the second flag, wherein the third flag is a deblocking filter information in picture header flag and specifies whether deblocking filter information is present in a picture header syntax structure and not present in slice headers referring to the picture parameter set, wherein the chroma deblocking offset syntax elements are conditionally parsed based on the value of the first flag;
derive quantization parameters based on the chroma tool offsets related syntax elements; and
perform a deblocking filter based on the chroma deblocking offset syntax elements, wherein the second flag and the third flag are ordered in the picture parameter set between the chroma tool offsets related syntax elements and the chroma deblocking offset syntax elements.