Patent ID: 9161046
Filing Date: 2015-10-13
Classification: H04N

Abstract:
1. A method of decoding video data, the method comprising: extracting from a coded representation of the video data, a plurality of syntax elements, the syntax elements including a first delta quantization parameter (dQP) syntax element and a second dQP syntax element, wherein a picture of the video data is partitioned into a plurality of Largest Coding Units (LCUs), the plurality of LCUs including a particular LCU that includes a plurality of coding units (CUs), each respective CU of the plurality of CUs corresponding to a respective video block, the CUs of the particular LCU being grouped into a plurality of quantization groups that includes at least a first quantization group and a second quantization group; adding the first dQP syntax element to a predicted quantization parameter (QP) value from a first neighboring CU to determine a first QP value, wherein the first QP value is associated with each CU in the first quantization group; adding the second dQP syntax element to a predicted QP value from a second each CU in the second quantization group, the second-quantization group including multiple CUs or the particular LCU, each of the CUs of the second quantization group having a size smaller than a minimum CU quantization group size, wherein all leaf CUs within any CU having the minimum CU quantization group size share the same QP value, and wherein a dQP syntax element is only signaled for any leaf CU if the leaf CU is large than or equal to the minimum CU quantization group size; determining a deblocking QP value based on an average of the first QP value and the second QP value; identifying threshold values based on the deblocking QP value; making a determination, based on the threshold values, whether to apply a strong deblocking filter or a weak deblocking filter; and applying a deblocking filter based on the deblocking QP value to an edge occurring at a boundary between a first video block and a second video block, the first video block being associated with a first CU, the second video block being associated with a second CU, the first CU being in the first quantization group, the second CU being in the second quantization group, wherein applying the deblocking filter comprises: applying, in response to making the determination to apply the strong deblocking filter, the strong deblocking filter to modify samples of the first video block up to three samples away from the boundary and to modify samples of the second video block up to three samples away from the boundary; and applying, in response to making the determination to apply the weak deblocking filter, the weak deblocking filter to modify samples of the first video block up to two samples away from the boundary and to modify samples of the second video block up to two samples away from the boundary.