 any primary coded VCL NAL unit with particular values of dependency_id quality_id, and temporal_io the scalability information SEI message shall not contain information for a scalable layer with dependency_id[i quality_id[i and temporal_id[i equal to the particular values of dependency_id, quality_id, and temporal_id, respectively. NOTE 5 - When an application removes NAL units from a scalable bitstream, e.g. in order to adapt the bitstream to a transmission channel or the capabilities of a receiving device, and keeps the present scalability information SEI messages, it might need to modify the content of the scalability information SEI messages in order to obtain a bitstream conforming to this Recommendation International Standard. Rec. ITU-T H.264 (01/2012) sub_pic_layer_flag| i ] specifies whether the current scalable layer represents a sub-picture scalable layer as specified subsequently. Depending on sub_pic_layer_flag[ ], the following applies: If sub_pic_layer_flag[ is equal to 0, the current scalable layer does not represent a sub-picture scalable layer. The VCL NAL units of the current scalable layer are all VCL NAL units of the target access unit set that have dependency_id quality_id, and temporal_id equal to dependency_id[i], quality_id[i] and temporal_id[i respectively. Otherwise (sub_pic_layer_flag[ i ] is equal to 1), the current scalable layer represents a sub-picture scalable layer and is associated with a sub-picture area as specified in the following: (a) The sub-picture area is a rectangular area of slice group map units inside the layer frames with dependency id equal to dependency_ic and represents a proper subset of the area of the layer frames with dependency_io equal to dependency_id i]. The sub-picture area associated with a sub-picture scalable layer does not change inside the target access unit set. The sub-picture area is specified by the syntax elements horizontal_offset[ ], vertical offset[ ], region_width[ ], and region_height[ as specified later in this clause. NOTE 6 - The sub-p