shall be inferred to be equal to chroma_phase_x_plus1_flag. eq_ref_layer_chroma_phase_y_plus1 specifies the vertical phase shift of the chroma components in units of half luma samples of a layer frame for the layer pictures that may be used for inter-layer prediction. When seq_ref_layer_chroma_phase_y_plus1 is not present, it shall be inferred to be equal to chroma_phase_y_plusl. The value of seq_ref_layer_chroma_phase_y_plus1 shall be in the range of 0 to 2, inclusive. seq_scaled_ref_layer_left_offsetspecifies the horizontal offset between the upper-left luma sample of a resampled layer picture used for inter-layer prediction the upper-left luma sample of the current picture or current layer picture units of two luma samples.When seq_scaled_ref_layer_left_offset is not present, it shall be inferred to be equal to 0. The value of seq_scaled_ref_layer_left_offset shall be in the range of -215 to 215 1, inclusive. seq_scaled_ref_layer_top_offset specifies the vertical offset between the upper-left luma sample of a resampled layer picture used for inter-layer prediction and the upper-left luma sample of the current picture or current layer picture. Depending on the value of frame_mbs_only_flag, following applies: - If equal to 1, the vertical offset is specified in units of two luma samples. Rec. ITU-T H.264 (01/2012) Otherwise (frame_mbs_only_flag is equal to 0), the vertical offset is specified in units of four luma samples. When seq_scaled_ref_layer_top_offset is not present, it shall be inferred to be equal to 0. The value of seq_scaled_ref_layer_top_offset shall be in the range of -215 to 215 - 1, inclusive. seq_scaled_ref_layer_right_offset specifies the horizontal offset between the bottom-right luma sample of a resampled layer picture used for inter-layer prediction and the bottom-right luma sample of the current picture or current layer picture in units of two luma samples. When seq_scaled_ref_layer_right_offser is not present, it shall be inferred to be equal to 0. The value of fseq_scaled_ref_layer_right_