阅读说明：本技术 预测方向的确定方法、解码器以及计算机存储介质 (Method for determining prediction direction, decoder and computer storage medium ) 是由 霍俊彦 马彦卓 王江林 万帅 杨付正 于 2019-01-02 设计创作，主要内容包括：一种预测方向的确定方法、解码器以及计算机存储介质,所述方法应用于一解码器中,所述方法包括：获取待解码块的色度帧内预测模式中DM模式(S101)；根据DM模式的预测方向的索引号M和预设的偏移量N,确定DM推导模式的预测方向的索引号,以确定DM推导模式(S102)。(A method for determining a prediction direction, a decoder and a computer storage medium, the method being applied to a decoder, the method comprising: acquiring a DM mode in a chroma intra-prediction mode of a block to be decoded (S101); and determining the index number of the prediction direction of the DM derivation mode according to the index number M of the prediction direction of the DM mode and the preset offset N to determine the DM derivation mode (S102).)

A method for determining a prediction direction, wherein the method is applied to a decoder, and the method comprises:

acquiring a same-position brightness DM mode in a chroma intra-frame prediction mode of a block to be decoded;

determining the index number of the prediction direction of the DM derivation mode according to the index number M of the prediction direction of the DM mode and a preset offset N so as to determine the DM derivation mode;

wherein N is a positive integer greater than or equal to 2, and M is a positive integer.

The method according to claim 1, wherein the determining the index number of the prediction direction of the DM derivation mode according to the index number M of the prediction direction of the DM mode and a preset offset N to determine the DM derivation mode comprises:

summing M and N to obtain a sum value, and subtracting M and N to obtain a difference value;

acquiring a minimum value K1 of the index numbers of the prediction directions contained in the DM mode and a maximum value K2 of the index numbers of the prediction directions contained in the DM mode;

determining an index number of a prediction direction of the DM derivation mode according to the sum, the difference, K1 and K2 to determine the DM derivation mode.

The method of claim 2, wherein the determining an index number of a prediction direction of the DM derivation mode according to the sum and the difference to determine the DM derivation mode comprises:

when the sum is less than or equal to K2 and the difference is greater than or equal to K1, determining the index numbers of the prediction directions of the DM derivation mode to be the sum and the difference, respectively;

when the difference is less than or equal to K1, determining the index numbers of the prediction directions of the DM derivation mode as the sum value and a first output value respectively; the first output value is obtained by inputting M and N into a preset first preset formula;

when the sum is greater than or equal to K2, determining the index numbers of the prediction directions of the DM derivation mode as a second output value and the difference value respectively; and the second output value is obtained by inputting M and N into a preset second preset formula.

The method of claim 2, wherein the determining an index number of a prediction direction of the DM derivation mode according to the sum and the difference to determine the DM derivation mode comprises:

when the sum is less than or equal to K2 and the difference is greater than or equal to K1, determining the index numbers of the prediction directions of the DM derivation mode as the sum and the difference respectively;

when the difference value is less than or equal to K1, determining the index numbers of the prediction directions of the DM derivation mode as the sum value and K1 respectively;

and when the sum is greater than or equal to K2, determining the index numbers of the prediction directions of the DM derivation mode as the difference and K2 respectively.

The method according to claim 2, wherein, when the index number of the prediction direction included in the DM mode is different from the index number of the prediction direction included in the block to be decoded, correspondingly, the determining the index number of the prediction direction of the DM derivation mode according to the sum and the difference to determine the DM derivation mode comprises:

acquiring a minimum value L1 of the index numbers of the prediction directions contained in the block to be decoded and a maximum value L2 of the index numbers of the prediction directions contained in the DM mode;

acquiring a corresponding relation between the index number of the prediction direction contained in the DM mode and the index number of the prediction direction contained in the block to be decoded;

according to the sum value, the difference value, L1 and L2, determining an index number from index numbers of prediction directions contained in the block to be decoded;

and according to the corresponding relation, determining the index number of the prediction direction of the DM mode corresponding to the determined index number as the index number of the prediction direction of the DM derivation mode so as to determine the DM derivation mode.

The method of claim 5, wherein said determining an index number from the index numbers of the prediction directions contained in the block to be decoded according to the sum, the difference, L1 and L2 comprises:

when the sum is less than or equal to L2 and the difference is greater than or equal to L1, the determined index numbers are the sum and the difference respectively;

when the difference value is less than or equal to L1, the determined index numbers are the sum value and a third output value respectively; the third output value is obtained by inputting M and N into a preset third preset formula;

when the sum is greater than or equal to L2, the determined index numbers are respectively a fourth output value and the difference value; and the fourth output value is obtained by inputting M and N into a preset fourth preset formula.

The method of claim 5, wherein said determining an index number from the index numbers of the prediction directions contained in the block to be decoded according to the sum, the difference, L1 and L2 comprises:

when the sum is less than or equal to L2 and the difference is greater than or equal to L1, the determined index numbers are the sum and the difference respectively;

when the difference value is less than or equal to L1, the determined index numbers are the sum value and L1 respectively;

when the sum is greater than or equal to L2, the determined index numbers are the difference and L2, respectively.

The method of claim 1, wherein after determining the index number of the prediction direction of the DM derivation mode according to the index number M of the prediction direction of the DM mode and a preset offset N to determine the DM derivation mode, the method further comprises:

determining that a decoding priority of the DM derivation mode is lower than a priority of the DM mode and lower than a decoding priority of a cross-component linear model prediction (CCLM) mode.

The method of claim 8, wherein after determining the index number of the prediction direction of the DM derivation mode according to the index number M of the prediction direction of the DM mode and a preset offset N to determine the DM derivation mode, the method further comprises:

determining that a decoding priority of the DM derivation mode is lower than a decoding priority of the DM mode, and lower than a decoding priority of the CCLM mode, and higher than a decoding priority of the vertical VER mode, and higher than a decoding priority of the horizontal HOR mode.

The method of claim 8, wherein after determining the index number of the prediction direction of the DM derivation mode according to the index number M of the prediction direction of the DM mode and a preset offset N to determine the DM derivation mode, the method further comprises:

determining that a decoding priority of the DM derivation mode is lower than a decoding priority of the DM mode, and lower than a decoding priority of the CCLM mode, and lower than a decoding priority of the DC-DC mode, and lower than a decoding priority of the gradual-flat PLANAR mode.

The method according to claim 9 or 10, wherein after determining the index number of the prediction direction of the DM derivation mode according to the index number M of the prediction direction of the DM mode and a preset offset N to determine the DM derivation mode, the method further comprises:

determining that a decoding priority of the DM derivation mode is lower than a decoding priority of the DM mode, and lower than a decoding priority of the CCLM mode, and lower than a decoding priority of the DC mode, and lower than a decoding priority of the PLANAR mode, and higher than a decoding priority of the VER mode, and higher than a decoding priority of the HOR mode.

A decoder, wherein the decoder comprises:

the acquisition module is used for acquiring a same-position brightness DM mode in a chroma intra-frame prediction mode of a block to be decoded;

a first determining module, configured to determine, according to the index number M of the prediction direction of the DM mode and a preset offset N, the index number of the prediction direction of the DM derivation mode to determine the DM derivation mode;

wherein N is a positive integer greater than or equal to 2, and M is a positive integer.

The decoder of claim 12, wherein the first determining module comprises:

the calculation submodule is used for summing the M and the N to obtain a sum value and subtracting the M and the N to obtain a difference value;

a first obtaining sub-module, configured to obtain a minimum value K1 of the index numbers of the prediction directions included in the DM mode and a maximum value K2 of the index numbers of the prediction directions included in the DM mode;

a first determining sub-module for determining an index number of a prediction direction of the DM derivation mode according to the sum, the difference, K1 and K2 to determine the DM derivation mode.

The decoder according to claim 13, wherein the first determining submodule is specifically configured to:

when the sum is less than or equal to K2 and the difference is greater than or equal to K1, determining the index numbers of the prediction directions of the DM derivation mode to be the sum and the difference, respectively;

when the difference is less than or equal to K1, determining the index numbers of the prediction directions of the DM derivation mode as the sum value and a first output value respectively; the first output value is obtained by inputting M and N into a preset first preset formula;

when the sum is greater than or equal to K2, determining the index numbers of the prediction directions of the DM derivation mode as a second output value and the difference value respectively; and the second output value is obtained by inputting M and N into a preset second preset formula.

The decoder according to claim 13, wherein the first determining submodule is specifically configured to:

when the sum is less than or equal to K2 and the difference is greater than or equal to K1, determining the index numbers of the prediction directions of the DM derivation mode as the sum and the difference respectively;

when the difference value is less than or equal to K1, determining the index numbers of the prediction directions of the DM derivation mode as the sum value and K1 respectively;

and when the sum is greater than or equal to K2, determining the index numbers of the prediction directions of the DM derivation mode as the difference and K2 respectively.

The decoder according to claim 13, when the index number of the prediction direction included in the DM mode is different from the index number of the prediction direction included in the block to be decoded, the first determining sub-module correspondingly comprises:

a second obtaining sub-module, configured to obtain a minimum value L1 of the index numbers of the prediction directions included in the block to be decoded, and a maximum value L2 of the index numbers of the prediction directions included in the DM mode;

a third obtaining sub-module, configured to obtain a correspondence between an index number of the prediction direction included in the DM mode and an index number of the prediction direction included in the block to be decoded;

a second determining submodule, configured to determine an index number from index numbers of prediction directions included in the block to be decoded according to the sum, the difference, L1, and L2;

and a third determining submodule, configured to determine, according to the correspondence, an index number of the prediction direction of the DM mode corresponding to the determined index number as an index number of the prediction direction of the DM derivation mode, so as to determine the DM derivation mode.

The decoder according to claim 16, wherein the second determining sub-module is specifically configured to:

when the sum is less than or equal to L2 and the difference is greater than or equal to L1, the determined index numbers are the sum and the difference respectively;

when the difference value is less than or equal to L1, the determined index numbers are the sum value and a third output value respectively; the third output value is obtained by inputting M and N into a preset third preset formula;

when the sum is greater than or equal to L2, the determined index numbers are respectively a fourth output value and the difference value; and the fourth output value is obtained by inputting M and N into a preset fourth preset formula.

The decoder according to claim 16, wherein the second determining sub-module is specifically configured to:

when the sum is less than or equal to L2 and the difference is greater than or equal to L1, the determined index numbers are the sum and the difference respectively;

when the difference value is less than or equal to L1, the determined index numbers are the sum value and L1 respectively;

when the sum is greater than or equal to L2, the determined index numbers are the difference and L2, respectively.

The decoder of claim 12, wherein the decoder further comprises:

and the second determining module is used for determining the index number of the prediction direction of the DM derivation mode according to the index number M of the prediction direction of the DM mode and a preset offset N so as to determine the DM derivation mode, and then determining that the decoding priority of the DM derivation mode is lower than the priority of the DM mode and lower than the decoding priority of the cross-component linear model prediction CCLM mode.

The decoder according to claim 19, wherein the second determining module is specifically configured to:

determining that a decoding priority of the DM derivation mode is lower than a decoding priority of the DM mode, and lower than a decoding priority of the CCLM mode, and higher than a decoding priority of the vertical VER mode, and higher than a decoding priority of the horizontal HOR mode.

The decoder according to claim 19, wherein the second determining module is specifically configured to:

determining that a decoding priority of the DM derivation mode is lower than a decoding priority of the DM mode, and lower than a decoding priority of the CCLM mode, and lower than a decoding priority of the DC-DC mode, and lower than a decoding priority of the gradual-flat PLANAR mode.

The decoder according to claim 20 or 21, wherein the second determining module is specifically configured to:

determining that a decoding priority of the DM derivation mode is lower than a decoding priority of the DM mode, and lower than a decoding priority of the CCLM mode, and lower than a decoding priority of the DC mode, and lower than a decoding priority of the PLANAR mode, and higher than a decoding priority of the VER mode, and higher than a decoding priority of the HOR mode.

A decoder, wherein the decoder comprises:

a processor and a storage medium storing instructions executable by the processor to perform operations dependent on the processor via a communication bus, the instructions when executed by the processor performing the method of determining a prediction direction according to any of the preceding claims 1 to 11.

A computer storage medium having stored thereon executable instructions which, when executed by one or more processors, perform the method of determining a prediction direction of any one of claims 1 to 11.