Generalized bi-prediction and weighted prediction

Abstract

A decoding method is presented. At least one high level syntax element is decoded that indicates whether generalized bi-prediction applies for predicting blocks of a slice. A block is then decoded from said slice using generalized bi-prediction in the case where said at least one high level syntax element indicates to apply generalized bi-prediction.

1 - 17 . (canceled) 
     
     
         18 . A decoding method comprising:
 obtaining a first value of a first high level syntax element, the first high level syntax element indicating whether a group-of-blocks level weighted prediction applies for predicting blocks;   obtaining a second value of a second high level syntax element, the second high level syntax element indicating whether a block-level generalized bi-prediction mode applies for predicting blocks; and   decoding a current block by applying the block-level generalized bi-prediction mode responsive to the first value indicating the group-of-blocks-level weighted prediction mode applies, the second value indicating the block-level generalized bi-prediction mode applies, and at least one block level parameter of the current block related to a feature of the group-of-blocks level weighted prediction mode has a value compliant with an application of the block-level generalized bi-prediction mode.   
     
     
         19 . The method of  claim 18 , wherein the first and second high level syntax elements are decoded from a sequence parameter set, a picture parameter set, a tile header or from a slice header. 
     
     
         20 . The method of  claim 18 , further comprising decoding the at least one parameter responsive to a condition on the current block indicating whether the at least one parameter is coded explicitly is fulfilled and the second high level syntax element indicating the block-level generalized bi-prediction mode applies. 
     
     
         21 . The method of  claim 18 , wherein the at least one block level parameter of the current block related to a feature of the group-of-blocks level weighted prediction mode comprises at least one parameter representative of a value of a weight and at least one parameter representative of a value of an offset. 
     
     
         22 . The method of  claim 21 , wherein the at least one parameter representative of a value of a weight compliant with an application of the block-level generalized bi-prediction mode is representative of a value of a weight equal to one and the at least one parameter representative of a value of an offset compliant with an application of the block-level generalized bi-prediction mode is representative of a value of an offset equal to zero. 
     
     
         23 . A non-transitory information storage medium storing instructions for implementing the method according to  claim 18 . 
     
     
         24 . An encoding method comprising:
 obtaining a first value of a first high level syntax element, the first high level syntax element indicating whether a group-of-blocks level weighted prediction applies for predicting blocks;
 obtaining a second value of a second high level syntax element, the second high level syntax element indicating whether a block-level generalized bi-prediction mode applies for predicting blocks; and 
 encoding a current block by applying the block-level generalized bi-prediction mode responsive to the first value indicating the group-of-blocks-level weighted prediction mode applies, the second value indicating the block-level generalized bi-prediction mode applies, and at least one block level parameter of the current block related to a feature of the group-of-blocks level weighted prediction mode has a value compliant with an application of the block-level generalized bi-prediction mode. 
   
     
     
         25 . The method of  claim 24 , wherein the first and second high level syntax elements are encoded in a sequence parameter set, a picture parameter set, a tile header or in a slice header. 
     
     
         26 . The method of  claim 24 , further comprising encoding the at least one parameter responsive to a condition on the current block indicating whether the at least one parameter is coded explicitly is fulfilled and the second high level syntax element indicating the block-level generalized bi-prediction mode applies. 
     
     
         27 . The method of  claim 24 , wherein the at least one block level parameter of the current block related to a feature of the group-of-blocks level weighted prediction mode comprises at least one parameter representative of a value of a weight and at least one parameter representative of a value of an offset. 
     
     
         28 . The method of  claim 27 , wherein the at least one parameter representative of a value of a weight compliant with an application of the block-level generalized bi-prediction mode is representative of a value of a weight equal to one and the at least one parameter representative of a value of an offset compliant with an application of the block-level generalized bi-prediction mode is representative of a value of an offset equal to zero. 
     
     
         29 . A non-transitory information storage medium storing instructions for implementing the method according to  claim 24 . 
     
     
         30 . A decoding apparatus comprising:
 one or more processors configured to perform:   obtaining a first value of a first high level syntax element, the first high level syntax element indicating whether a group-of-blocks level weighted prediction applies for predicting blocks;   obtaining a second value of a second high level syntax element, the second high level syntax element indicating whether a block-level generalized bi-prediction mode applies for predicting blocks; and   decoding a current block by applying the block-level generalized bi-prediction mode responsive to the first value indicating the group-of-blocks-level weighted prediction mode applies, the second value indicating the block-level generalized bi-prediction mode applies, and at least one block level parameter of the current block related to a feature of the group-of-blocks level weighted prediction mode has a value compliant with an application of the block-level generalized bi-prediction mode.   
     
     
         31 . The decoding apparatus of  claim 30 , wherein the first and second high level syntax elements are decoded from a sequence parameter set, a picture parameter set, a tile header or from a slice header. 
     
     
         32 . The decoding apparatus of  claim 30 , wherein the one or more processors are further configured to perform decoding the at least one parameter responsive to a condition on the current block indicating whether the at least one parameter is coded explicitly is fulfilled and the second high level syntax element indicating the block-level generalized bi-prediction mode applies. 
     
     
         33 . The decoding apparatus of  claim 30 , wherein the at least one block level parameter of the current block related to a feature of the group-of-blocks level weighted prediction mode comprises at least one parameter representative of a value of a weight and at least one parameter representative of a value of an offset. 
     
     
         34 . The decoding apparatus of  claim 33 , wherein the at least one parameter representative of a value of a weight compliant with an application of the block-level generalized bi-prediction mode is representative of a value of a weight equal to one and the at least one parameter representative of a value of an offset compliant with an application of the block-level generalized bi-prediction mode is representative of a value of an offset equal to zero. 
     
     
         35 . An encoding apparatus comprising:
 one or more processors configured to perform:   obtaining a first value of a first high level syntax element, the first high level syntax element indicating whether a group-of-blocks level weighted prediction applies for predicting blocks;   obtaining a second value of a second high level syntax element, the second high level syntax element indicating whether a block-level generalized bi-prediction mode applies for predicting blocks; and   encoding a current block by applying the block-level generalized bi-prediction mode responsive to the first value indicating the group-of-blocks-level weighted prediction mode applies, the second value indicating the block-level generalized bi-prediction mode applies, and at least one block level parameter of the current block related to a feature of the group-of-blocks level weighted prediction mode has a value compliant with an application of the block-level generalized bi-prediction mode.   
     
     
         36 . The encoding apparatus of  claim 35 , wherein the first and second high level syntax elements are encoded in a sequence parameter set, a picture parameter set, a tile header or in a slice header. 
     
     
         37 . The encoding apparatus of  claim 35 , wherein the one or more processors are further configured to perform encoding the at least one parameter responsive to a condition on the current block indicating whether the at least one parameter is coded explicitly is fulfilled and the second high level syntax element indicating the block-level generalized bi-prediction mode applies. 
     
     
         38 . The encoding apparatus of  claim 35 , wherein the at least one block level parameter of the current block related to a feature of the group-of-blocks level weighted prediction mode comprises at least one parameter representative of a value of a weight and at least one parameter representative of a value of an offset. 
     
     
         39 . The encoding apparatus of  claim 38 , wherein the at least one parameter representative of a value of a weight compliant with an application of the block-level generalized bi-prediction mode is representative of a value of a weight equal to one and the at least one parameter representative of a value of an offset compliant with an application of the block-level generalized bi-prediction mode is representative of a value of an offset equal to zero.