ipred_4x4_ver, ipred_4x4_hor, ipred_4x4_dc,
ipred_4x4_diag_down_left, ipred_4x4_diag_down_right,
ipred_4x4_ver_right, ipred_4x4_hor_down, ipred_4x4_ver_left, ipred_4x4_hor_up,
ipred_4x4_ver, ipred_4x4_hor, ipred_4x4_dc,
ipred_4x4_diag_down_left, ipred_4x4_diag_down_right,
ipred_4x4_ver_right, ipred_4x4_hor_down, ipred_4x4_ver_left, ipred_4x4_hor_up,