segment, in coding tree block raster scan of the tile identified by slice tile id. The length of the slice_segment_address syntax element is Ceil( Log2( TileSizelnCtbsY ) ) bits, where TileSizelnCtbsY is the number of luma coding tree blocks of the tile. In another embodiment, block index wrt tile id has type ue(v) instead of u(v). [00149] In an embodiment, a block index relative to a tile is indicated with two syntax elements, one indicating a horizontal position of the block within the tile, and another indicating a vertical position of the block within the tile. The type of the two syntax elements may be e.g. ue(v) or u(v). When u(v) is used the length of the syntax elements may be determined by the number of block rows and the number of block columns. [00150] In some embodiments, the apparatus 10 further includes means, such as the processing circuitry 12, for constructing one or more motion vectors associated with one or more prediction units in one or more coding units in the one or more tiles. The one or more motion vectors comprise one or more anchor location identifiers, each defining a position relative to the one or more tiles indicated by the one or more tile identifiers. Motion vectors include anchor identifiers in the form of syntax elements indicative of a pre-defined position, such as tile ref x and tile ref y, referred to as the horizontal and vertical offset, respectively. As described above, the horizontal and vertical offset are used to determine an anchor position for applying the motion vector to obtain a prediction block. In an example illustrated in Figure 3, anchor indentifiers are used for 360-degree video, where a shared coded picture at base quality and tiles at enhanced quality are coded within the same coded picture, and where the shared coded picture and enhanced-quality tiles of the same coded picture originate from the same 360-degree pictuture. In Figure 3, anchor indentifiers for an enhanced-quality tile indicate a location within a shared constituent picture. [00151] In some embodiments, anchor position(s) for motion vectors are indicated through tile identifier(s), such as tile id value(s) or alike, rather than x and y sample coordinates relative to the picture. The motion vector anchor position is derived to be a pre-defined location relative to the tile identified by the tile identifier (e.g. the tile id value), such as the top-left comer of the tile identified by the tile identifier (e.g. the tile id value). [00152] An embodiment for decoding a coded tile into a decoded tile comprises the following: decoding a tile identifier intended for deriving a motion vector anchor position; deriving a tile position from the tile identifier; deriving a horizontal offset and a vertical offset from the tile position;