Video coding method and apparatus
The present invention relates to a method and apparatus for performing encoding and decoding using a variably-sized quantization coefficient group, in quantization coefficient group encoding and decoding of video compression technology.
1. A video decoding method, performed by a video decoding apparatus, comprising:
obtaining sub-group usage information indicating whether sub-group partitioning is usable for a sequence, the sub-group usage information being obtained from a sequence parameter set of a bitstream;
obtaining, based on the sub-group usage information, partition type information of a current coding unit from the bitstream, wherein the partition type information includes a partition flag indicating whether the current coding unit is partitioned into a plurality of sub-groups and partition direction information indicating whether the current coding unit is partitioned in a horizontal direction or in a vertical direction; and
decoding the current coding unit based on the partition flag,
wherein the partition flag equal to 1 indicates that the current coding unit is partitioned into the plurality of the sub-groups, and the partition flag equal to 0 indicates that the current coding unit is not partitioned into the plurality of the sub-groups,
wherein, in response to the partition flag equal to 1, a number of the sub-groups resulting from partitioning the current coding unit is adaptively determined based on a size of the current coding unit,
wherein, in response to the current coding unit with the partition flag equal to 1, coefficients of the current coding unit is scanned using a first scan order among a plurality of scan orders pre-defined in a decoding apparatus, and
wherein, in response to the current coding unit with the partition flag equal to 0, the coefficients of the current coding unit is scanned using a second scan order among the plurality of the scan orders pre-defined in the decoding apparatus.
2. The method of claim 1 , wherein, when the partition flag indicates that the current coding unit is not partitioned, the current coding unit is inverse-quantized based on the sub-group having a same size as the current coding unit.
3. The method of claim 1 , wherein, when the partition direction information indicates that the current coding unit is horizontally partitioned, the current coding unit is inverse-quantized based on at least two sub-groups resulting from partitioning the current coding unit horizontally.
4. The method of claim 1 , wherein, when the partition direction information indicates that the current coding unit is vertically partitioned, the current coding unit is inverse-quantized based on at least two sub-groups resulting from partitioning the current coding unit vertically.
5. A video encoding method, performed by a video encoding apparatus, comprising:
determining whether sub-group partitioning is usable for a sequence;
determining a partition type of a current coding unit in response to a case where the sub-group partitioning of a coding unit is usable for the sequence; and
encoding the current coding unit based on the determined partition type,
wherein sub-group usage information is encoded, based on a result of determining whether the sub-group partitioning is usable for the sequence, into a sequence parameter set of a bitstream,
wherein partition type information is encoded, based on the determined partition type, into a bitstream,
wherein the partition type information includes a partition flag indicating whether the current coding unit is partitioned into a plurality of sub-groups and partition direction information indicating whether the current coding unit is partitioned in a horizontal direction or in a vertical direction,
wherein the partition flag equal to 1 indicates that the current coding unit is partitioned into the plurality of the sub-groups, and the partition flag equal to 0 indicates that the current coding unit is not partitioned into the plurality of the sub-groups,
wherein, in response to the partition flag equal to 1, a number of the sub-groups resulting from partitioning the current coding unit is adaptively determined based on a size of the current coding unit,
wherein, in response to the current coding unit with the partition flag equal to 1, coefficients of the current coding unit is scanned using a first scan order among a plurality of scan orders pre-defined in an encoding apparatus, and
wherein, in response to the current coding unit with the partition flag equal to 0, the coefficients of the current coding unit is scanned using a second scan order among the plurality of the scan orders pre-defined in the encoding apparatus.
6. A non-transitory computer-readable medium for storing a bitstream associated with a video signal,
wherein the bitstream includes sub-group usage information indicating whether sub-group partitioning is usable for a sequence and partition type information of a current coding unit,
wherein the sub-group usage information is included in a sequence parameter set of the bitstream,
wherein the partition type information is obtained based on the sub-group usage information,
wherein the partition type information includes a partition flag indicating whether the current coding unit is partitioned into a plurality of sub-groups and partition direction information indicating whether the current coding unit is partitioned in a horizontal direction or in a vertical direction,
wherein the partition flag equal to 1 indicates that the current coding unit is partitioned into the plurality of the sub-groups, and the partition flag equal to 0 indicates that the current coding unit is not partitioned into the plurality of the sub-groups,
wherein, in response to the partition flag equal to 1, a number of the sub-groups resulting from partitioning the current coding unit is adaptively determined based on a size of the current coding unit,
wherein, in response to the current coding unit with the partition flag equal to 1, coefficients of the current coding unit is scanned using a first scan order among a plurality of pre-defined scan orders, and
wherein, in response to the current coding unit with the partition flag equal to 0, the coefficients of the current coding unit is scanned using a second scan order among the plurality of the pre-defined scan orders.