A method for sending a buffering period Supplemental Enhancement Information SEI message by an electronic device, comprising: coding first initial CPB removal delay initial_cpb_removal_delay, first initial CPB removal delay offset initial_cpb_removal_delay_offset, a flag cra_leadingpict_discard_flag which indicates whether second initial CPB removal delay initial_cra_cpb_removal_delay, second initial CPB removal delay offset initial_cra_cpb_removal_delay_offset, are present, and second initial CPB removal delay, second initial CPB removal delay offset when the flag indicates its presence, wherein the first initial CPB removal delay, the first initial CPB removal delay offset, the flag, second initial CPB removal delay and second initial CPB removal delay offset are in the buffering period Supplemental Enhancement Information SEI message, wherein initial removal delay variables are set to second initial CPB removal delay, and second initial CPB removal delay offset when a set of conditions is met, and initial removal delay variables are set to first initial CPB removal delay and first initial CPB removal delay offset when the set of conditions is not met, and sending the buffering period Supplemental Enhancement Information SEI message, wherein the initial arrival time for access unit is derived using 1/ either the first initial CPB removal delay or the second initial CPB removal delay and 2/ either the first initial CPB removal delay offset or the second initial CPB removal delay offset when the access unit is not first access unit and the initial arrival time for access unit is derived using either the first initial CPB removal delay or the second initial CPB removal delay when the access unit is first access unit, wherein the set of conditions includes the following, 1) a first access unit includes only I slice, 2) leading pictures are not present, and 3) the flag is equal to 1. coding first initial CPB removal delay initial_cpb_removal_delay, first initial CPB removal delay offset initial_cpb_removal_delay_offset, a flag cra_leadingpict_discard_flag which indicates whether second initial CPB removal delay initial_cra_cpb_removal_delay, second initial CPB removal delay offset initial_cra_cpb_removal_delay_offset, are present, and second initial CPB removal delay, second initial CPB removal delay offset when the flag indicates its presence, wherein the first initial CPB removal delay, the first initial CPB removal delay offset, the flag, second initial CPB removal delay and second initial CPB removal delay offset are in the buffering period Supplemental Enhancement Information SEI message, wherein initial removal delay variables are set to second initial CPB removal delay, and second initial CPB removal delay offset when a set of conditions is met, and initial removal delay variables are set to first initial CPB removal delay and first initial CPB removal delay offset when the set of conditions is not met, and sending the buffering period Supplemental Enhancement Information SEI message, wherein the initial arrival time for access unit is derived using 1/ either the first initial CPB removal delay or the second initial CPB removal delay and 2/ either the first initial CPB removal delay offset or the second initial CPB removal delay offset when the access unit is not first access unit and the initial arrival time for access unit is derived using either the first initial CPB removal delay or the second initial CPB removal delay when the access unit is first access unit, wherein the set of conditions includes the following, 1) a first access unit includes only I slice, 2) leading pictures are not present, and 3) the flag is equal to 1. 1) a first access unit includes only I slice, 2) leading pictures are not present, and 3) the flag is equal to 1.