f such a picture. D.2.21 Deblocking filter display preference SEI message semantics This SEI message provides the decoder with an indication of whether the display of the cropped result of the deblocking filter process specified in clause 8.7 or of the cropped result of the picture construction process prior to the deblocking filter process specified in clause 8.5.14 is preferred by the encoder for the display of each decoded picture that is output. NOTE 1 - The display process is not specified in this Recommendation | International Standard. The means by which an encoder determines what to indicate as its preference expressed in a deblocking filter display preference SEI message is also not specified in this Recommendation | International Standard, and the expression of an expressed preference in a deblocking filter display preference SEI message does not impose any requirement on the display process. deblocking_display_preference_cancel_flag equal to 1 indicates that the SEI message cancels the persistence of any previous deblocking filter display preference SEI message in output order.deblocking_display_preference_cancel_flag equal indicates display_prior_to_deblocking_preferred_flag deblocking_display_preference_repetition_period follow. NOTE 2 - In the absence of the deblocking filter display preference SEI message, or after the receipt of a deblocking filter display preference SEI message in which deblocking_display_preference_cancel_flag is equal to 1, the decoder should infer that the display of the cropped result of the deblocking filter process specified in clause 8.7 is preferred over the display of the cropped result of the picture construction process prior to the deblocking filter process specified in clause 8.5.14 for the display of each decoded picture that is output. display_prior_to_deblocking_preferred_flag equal to 1 indicates that the encoder preference is for the display process (which is not specified in this Recommendation | International Standard) to display the cropped result of the pict