ependency_id[ sub_pic_layer_flag[ a ] is equal to 1, and one of the following conditions is true: sub_pic_layer_flag[ b ] is equal to 0, sub_pic_layer_flag[ is equal to 1 and (horizontal_offset[ a is not equal to horizontal_offset[ b ] vertical offset[ a ] is not equal to vertical_offset[ region_width[ is not equal to region_width[b], or region_height[ a ] is not equal to region_height[ NOTE 1 - Sub-picture scalable layers with a particular value of dependency id and a particular sub-picture area are only considered to depend on scalable layers with the same value of dependency_id when these scalable layers are associated with the same sub-picture area. A scalable layer A is indirectly dependent on a scalable layer B when the scalable layer A is not directly dependent on the scalable layer B but there exists a set of n (with n being greater than 0) scalable layers {Co, Cn-1} with the following properties: The scalable layer A is directly dependent on the scalable layer C0, each scalable layer C with i in the range of 0 to n - 2, inclusive, is directly dependent on the scalable layer Ci+1, and the scalable layer Cn-1 is directly dependent on the scalable layer B. The representation of a particular scalable layer is the set of NAL units that represents the set union of the particular scalable layer and all scalable layers on which the particular scalable layer directly or indirectly depends. The representation of a scalable layer is also referred to as scalable layer representation. In the following specification of this clause, the terms representation of a scalable layer and scalable layer representation are also used for referring to the access unit set that can be constructed from the NAL units of the scalable layer representation. A scalable layer representation can be decoded independently of all NAL units that do not belong to the scalable layer representation. The decoding result of a scalable layer representation is the set of decoded pictures that are obtained by decoding the access unit set of the scalab