Video decoding method and video decoder
A video decoding method includes obtaining a to-be-entropy-decoded syntax element in a current block by parsing a received bitstream, where the to-be-entropy-decoded syntax element includes a syntax element 1 or a syntax element 2 in the current block, obtaining a context model corresponding to the to-be-entropy-decoded syntax element, where both of a context model corresponding to the syntax element 1 and a context model corresponding to the syntax element 2 are determined from the same preset context model set, entropy decoding the to-be-entropy-decoded syntax element based on the context model corresponding to the to-be-entropy-decoded syntax element, and obtaining a reconstructed image of the current block based on the syntax element obtained by entropy decoding.
1. A method comprising:
parsing a received bitstream to obtain information corresponding to a quantized coefficient and to a to-be-entropy-decoded syntax element in a current block, wherein the to-be-entropy-decoded syntax element comprises a first syntax element or a second syntax element, and wherein either the first syntax element is a first flag indicating whether a subblock-based merge mode is used for the current block or the second syntax element is a second flag indicating whether an affine motion model-based advanced motion vector prediction (AMVP) mode is used for the current block when a slice in which the current block is located is a P-type slice or a B-type slice;
obtaining a first context model corresponding to the to-be-entropy-decoded syntax element;
performing entropy decoding on the to-be-entropy-decoded syntax element based on the first context model;
obtaining the quantized coefficient based on the information;
performing inverse quantization on the quantized coefficient to obtain an inverse quantized coefficient;
performing prediction processing on the current block based on a third syntax element that is in the current block and that is based on entropy decoding in order to obtain a prediction block of the current block; and
obtaining a reconstructed image of the current block based on the prediction block and the inverse quantized coefficient.
2. The method of claim 1 , wherein a second context model corresponding to the first syntax element is based on a preset context model set by determining a first context index of the first syntax element based on a fourth syntax element and a fifth syntax element in a left neighboring block of the current block and a sixth syntax element and a seventh syntax element in an upper neighboring block of the current block, and wherein the first context index indicates the second context model.
3. The method of claim 1 , wherein a third context model corresponding to the second syntax element is based on a preset context model set by determining a second context index of the second syntax element in the current block based on a fourth syntax element and a fifth syntax element in a left neighboring block of the current block and a sixth syntax element and a seventh syntax element in an upper neighboring block of the current block, and wherein the second context index indicates the third context model.
4. A video decoding device, comprising:
a non-transitory memory storage configured to store video data in a form of a bitstream, wherein the bitstream comprises information corresponding to a quantized coefficient and to a to-be-entropy-decoded syntax element in a current block, and wherein the to-be-entropy-decoded syntax element comprises a first syntax element or a second syntax element, and wherein either the first syntax element is a first flag indicating whether a subblock-based merge mode is used for the current block or the second syntax element is a second flag indicating whether an affine motion model-based advanced motion vector prediction (AMVP) mode is used for the current block when a slice in which the current block is located is a P-type slice or a B-type slice; and
a video decoder coupled to the non-transitory memory storage and configured to:
parse the bitstream to obtain the information corresponding to the quantized coefficient and to the to-be-entropy-decoded syntax element;
obtain a first context model corresponding to the to-be-entropy-decoded syntax element;
perform entropy decoding on the to-be-entropy-decoded syntax element based on the first context model;
obtain the quantized coefficient based on the information;
perform inverse quantization on the quantized coefficient to obtain an inverse quantized coefficient;
perform prediction processing on the current block based on a third syntax element that is in the current block and that is based on entropy decoding in order to obtain a prediction block of the current block; and
obtain a reconstructed image of the current block based on the prediction block and the inverse quantized coefficient.
5. The video decoding device of claim 4 , wherein the video decoder is further configured to determine a first context index of the first syntax element based on a fourth syntax element and a fifth syntax element in a left neighboring block of the current block and a sixth syntax element and a seventh syntax element in an upper neighboring block of the current block, and wherein the first context index indicates a second context model corresponding to the first syntax element and based on a preset context model set.
6. The video decoding device of claim 4 , wherein the video decoder is further configured to determine a second context index of the second syntax element based on a fourth syntax element and a fifth syntax element in a left neighboring block of the current block and a sixth syntax element and a seventh syntax element in an upper neighboring block of the current block, and wherein the second context index indicates a third context model corresponding to the second syntax element based on a preset context model set.
7. A video encoding device comprising:
one or more memories configured to store programming instructions; and
one or more processors coupled to the one or more memories and configured to execute the programming instructions to cause the video encoding device to:
obtain a quantized coefficient by performing quantization;
obtain a to-be-entropy-encoded syntax element in a current block, wherein the to-be-entropy-encoded syntax element in the current block comprises a first syntax element or a second syntax element, and wherein either the first syntax element is a first flag indicating whether a subblock-based merge mode is used for the current block or the second syntax element is a second flag indicating whether an affine motion model-based advanced motion vector prediction (AMVP) mode is used for the current block when a slice in which the current block is located is a P-type slice or a B-type slice;
obtain a first context model corresponding to the to-be-entropy-encoded syntax element;
perform entropy encoding on the to-be-entropy-encoded syntax element based on the first context model;
generate a bitstream, wherein the bitstream comprises information corresponding to the quantized coefficient and comprises entropy encoded syntax element corresponding to the to-be-entropy-encoded syntax element; and
transmit the bitstream to a video decoding device.
8. The video encoding device of claim 7 , wherein the one or more processors further cause the video encoding device to determine a first context index of the first syntax element based on a third syntax element and a fourth syntax element in a left neighboring block of the current block and a fifth syntax element and a sixth syntax element in an upper neighboring block of the current block, and wherein the first context index indicates a second context model corresponding to the first syntax element and based on a preset context model set.
9. The video encoding device of claim 7 , wherein the one or more processors further cause the video encoder to determine a second context index of the second syntax element based on a third syntax element and a fourth syntax element in a left neighboring block of the current block and a fifth syntax element and a sixth syntax element in an upper neighboring block of the current block, and wherein the second context index indicates a third context model corresponding to the second syntax element and based on a preset context model set.
10. A non-transitory storage medium storing an encoded bitstream for video signals, wherein the encoded bitstream comprises:
information corresponding to a quantized coefficient based on performing quantization; and
a to-be-entropy-decoded syntax element in a current block,
wherein the to-be-entropy-decoded syntax element comprises a first syntax element or a second syntax element,
wherein both of a first context model corresponding to the first syntax element and a second context model corresponding to the second syntax element are based on a same preset context model set, and
wherein either the first syntax element is a first flag indicating whether a subblock-based merge mode is used for the current block or the second syntax element is a second flag indicating whether an affine motion model-based advanced motion vector prediction (AMVP) mode is used for the current block when a slice in which the current block is located is a P-type slice or a B-type slice.
11. The non-transitory storage medium of claim 10 , wherein the first context model is determined based on a third syntax element and a fourth syntax element in a left neighboring block of the current block and a fifth syntax element and a sixth syntax element in an upper neighboring block of the current block, and wherein a first context index of the first syntax element indicates the context model corresponding to the first syntax element.
12. The non-transitory storage medium of claim 10 , wherein the second context model is determined based on a third syntax element and a fourth syntax element in a left neighboring block of the current block and a fifth syntax element and a sixth syntax element in an upper neighboring block of the current block, and wherein a first context index of the first syntax element indicates the context model corresponding to the first syntax element.
13. The method of claim 1 , wherein the AMVP mode comprises a translational model-based AMVP mode.
14. The method of claim 1 , wherein the AMVP mode comprises a non-translational model-based AMVP mode.
15. The video decoding device of claim 4 , wherein the AMVP mode comprises a translational model-based AMVP mode.
16. The video decoding device of claim 4 , wherein the AMVP mode comprises a non-translational model-based AMVP mode.
17. The video encoding device of claim 7 , wherein the AMVP mode comprises a translational model-based AMVP mode.
18. The video encoding device of claim 7 , wherein the AMVP mode comprises a non-translational model-based AMVP mode.
19. The non-transitory storage medium of claim 10 , wherein the AMVP mode comprises a translational model-based AMVP mode.
20. The non-transitory storage medium of claim 10 , wherein the AMVP mode comprises a non-translational model-based AMVP mode.