Relation between partition constraint elements
The present disclosure relates generally to video coding and picture partitioning methods. In particular, the disclosure is concerned with relations between partition constraint elements, by setting partitioning rules for different picture partitioning methods. The disclosure provides devices and corresponding methods for generating or processing a bitstream including encoded pictures, particularly for setting and including partition constraint element into the bitstream. One of the devices is configured to determine a minimum luma size of a leaf block resulting from quadtree splitting (MinQtSizeY), determine a maximum luma size of a coding block where partitioning using a binary tree splitting is allowed (MaxBtSizeY) based on the MinQtSizeY, and include information for the determined MinQtSizeY into the bitstream.
1. A device for decoding or processing a video bitstream, the device comprising circuitry configured to:
obtain, from the bitstream, a syntax element;
obtain information for a minimum size in luma samples of a luma leaf block resulting from quadtree splitting; and
determine a maximum size in luma samples of a luma root block where partitioning using binary tree splitting is allowed based on the information for the minimum size in luma samples of the luma leaf block resulting from quadtree splitting and the obtained syntax element;
wherein the syntax element is a syntax element of a difference between the base 2 logarithm of the minimum size in luma samples of the luma leaf block resulting from quadtree splitting and the base 2 logarithm of the maximum size in luma samples of the luma root block where partitioning using binary tree splitting is allowed; or
wherein the syntax element is a syntax element of a difference between the minimum size in luma samples of the luma leaf block resulting from quadtree splitting and the maximum size in luma samples of the luma root block where partitioning using binary tree splitting is allowed, wherein the syntax element of the difference is signaling said difference in logarithmic scale with base 2.
2. The device according to claim 1 , wherein the circuitry is configured to determine the maximum size in luma samples of the luma root block where partitioning using binary tree splitting is allowed considering that its lower limit is the minimum size in luma samples of the luma leaf block resulting from quadtree splitting.
3. The device according to claims 1 , wherein the circuitry is configured to obtain the syntax element from the bitstream dependent on a maximum hierarchy depth for coding units resulting from multi-type tree splitting.
4. The device according to claim 3 , wherein the circuitry is configured to obtain the syntax element from the bitstream, responsive to determining that the maximum hierarchy depth for coding units resulting from multi-type tree splitting is not equal to zero.
5. A device for encoding or generating a video bitstream, the device comprising circuitry configured to:
determine a minimum luma size of a leaf block resulting from quadtree splitting;
determine a maximum luma size of a coding block where partitioning using binary tree splitting is allowed based on the minimum luma size of the leaf block resulting from quadtree splitting;
include information for the determined minimum luma size of the leaf block resulting from quadtree splitting into the bitstream; and
include into the bitstream:
(i) a syntax element of a difference between the base 2 logarithm of the minimum luma size of the leaf block resulting from quadtree splitting and the base 2 logarithm of the maximum size in luma samples of the luma root block where partitioning using binary tree splitting is allowed, or
(ii) a syntax element of the difference between the minimum luma size of the leaf block resulting from quadtree splitting and the maximum size in luma samples of the luma root block where partitioning using binary tree splitting is allowed, wherein the syntax element of the difference is signaling said difference in logarithmic scale with base 2.
6. The device according to claim 5 , wherein the circuitry is further configured to:
determine the maximum size in luma samples of the luma root block where partitioning using binary tree splitting is allowed considering that its lower limit is the minimum size in luma samples of the luma leaf block resulting from quadtree splitting.
7. The device according to claims 5 , wherein the circuitry is further configured to:
include the syntax element into the bitstream, dependent on a maximum hierarchy depth for coding units resulting from multi-type tree splitting.
8. The device according to claim 7 , wherein the circuitry is further configured to:
include the syntax element into the bitstream, responsive to determining that the maximum hierarchy depth for coding units resulting from multi-type tree splitting is not equal to zero.
9. A method for generating a video bitstream, the method comprising:
determining a minimum luma size of a leaf block resulting from quadtree splitting;
determining a maximum luma size of a coding block where partitioning using binary tree splitting is allowed, based on the minimum luma size of the leaf block resulting from quadtree splitting;
including information for the determined minimum luma size of the leaf block resulting from quadtree splitting into the bitstream; and
including into the bitstream:
(i) a syntax element of a difference between the base 2 logarithm of the minimum luma size of the leaf block resulting from quadtree splitting and the base 2 logarithm of the maximum size in luma samples of the luma root block where partitioning using binary tree splitting is allowed, or
(ii) a syntax element of the difference between the minimum luma size of the leaf block resulting from quadtree splitting and the maximum size in luma samples of the luma root block where partitioning using binary tree splitting is allowed, wherein the syntax element of the difference is signaling said difference in logarithmic scale with base 2.
10. A method for decoding or processing a video bitstream, the method comprising:
obtaining, from the bitstream, a syntax element;
obtaining information for a minimum size in luma samples of a luma leaf block resulting from quadtree splitting; and
determining a maximum size in luma samples of a luma root block where partitioning using binary tree splitting is allowed, based on the minimum size in luma samples of the luma leaf block resulting from quadtree splitting and the syntax element
wherein the syntax element is a syntax element of a difference between the base 2 logarithm of the minimum size in luma samples of the luma leaf block resulting from quadtree splitting and the base 2 logarithm of the maximum size in luma samples of the luma root block where partitioning using binary tree splitting is allowed; or
wherein the syntax element is a syntax element of a difference between the minimum size in luma samples of the luma leaf block resulting from quadtree splitting and the maximum size in luma samples of the luma root block where partitioning using binary tree splitting is allowed, wherein the syntax element of the difference is signaling said difference in logarithmic scale with base 2.
11. A computer program product comprising program code for controlling a device to perform the method of claim 10 when the program code is executed by one or more processors of the device.
12. A computer program product comprising program code for controlling a device to perform the method of claim 9 when the program code is executed by one or more processors of the device.