**4.1 Early CU termination (ECU)**

This algorithm is used when switching from a depth p to the next p + 1. As **Figure 8** showed, if skip is the best current CU prediction mode, the sub-tree calculations can be skipped [23]. Thus, good mode is determined with rate distortion (RD) calculation cost [24]. The minimal RD cost relates to the skip mode that caused the stop of the partitioning [25].

Several works show that the most chosen mode was the skip [25]. This clarifies the detail that an excessive enhancement is obtained when the skip mode recognition is anticipated. This mode induces a better encoder performance since it denotes a block code deprived of residual information.
