specified by (D-18) log2_scale_factor specifies a scale factor used in the film grain characterization equations. comp_model_present_flag[ C ] equal to 0 indicates that film grain is not modelled on the c-th colour component, where C equal to 0 refers to the luma component, C equal to 1 refers to the Cb component, and C equal to 2 refers to the Cr component. comp_model_present_flag[ c ] equal to 1 indicates that syntax elements specifying modelling of film grain on colour component C are present in the SEI message. num_intensity_intervals_minus1[c plus 1 specifies the number of intensity intervals for which a specific set of model values has been estimated. NOTE 5 - The intensity intervals may overlap in order to simulate multi-generational film grain. num_model_values_minus1[c]p plus 1 specifies the number of model values present for each intensity interval in which the film grain has been modelled. The value of num_model_values_minus1| c ] shall be in the range of 0 to 5, inclusive. Rec. ITU-T H.264 (01/2012) intensity_interval_lower_bound[c ][ specifies the lower bound of the interval i of intensity levels for which the set of model values applies. intensity_interval_upper_bound[c][i) ] specifies the upper bound of the interval i of intensity levels for which the set of model values applies. Depending on model_id, the selection of the sets of model values is specified as follows: If model id is equal to 0, the average value of each block b of 8x8 samples in Idecoded referred as bavg, is used to select the sets of model values with index s[j ] that apply to all the samples in the block: for( = 0;i<=num_intensity_intervals_minus1[c];i++ if(bavg>=intensity_interval_lower_bound[c][i]&&bavg<=intensity_interval_upper_bound[c][i]) s[j]=i (D-19) Otherwise (model_id is equal to 1), the sets of model values used to generate the film grain are selected for each sample value in Idecoded as follows: i<=num_intensity_intervals_minus1[c];i+ if(Idecoded[x, y,c]>=intensity_interval_lower_bound[c][i]&& intensity_interval_upper_