Parallel motion estimation in video coding

A method for parallel motion estimation in a video encoder, the method comprising:

• dividing a largest coding unit (LCU) of a picture in a video stream into a plurality of prediction units (PUs) and into a plurality of non-overlapping parallel motion estimation regions (PMERs) of equal size, wherein a PMER of the plurality of PMERs comprises a plurality of the PUs;
• and
• performing motion estimation on the plurality of PUs in the PMER in parallel, wherein parallel motion estimation comprises construction of a merging candidate list for each PU in the PMER by:
• determining a spatial motion data (SMD) position corresponding to a spatial merging candidate for the PU;
• selecting motion data of the SMD position as the spatial merging candidate when the SMD position is not in the PMER and the motion data is available;
• and
• indicating that the spatial merging candidate is not available when the SMD position is in the PMER.

A method for decoding an encoded video bit stream in a video decoder, the method comprising:

• receiving a size of parallel motion estimation regions (PMERs) in an encoded largest coding unit (LCU) in encoded video stream;
• and
• decoding the encoded LCU, wherein the decoding comprises construction of a merging candidate list for a first inter-predicted PU comprised in a first PMER of the encoded LCU by:
• determining a spatial motion data (SMD) position corresponding to a spatial merging candidate for the first inter-predicted PU;
• selecting motion data of the SMD position as the spatial merging candidate when the SMD position is not in the first PMER and the motion data is available;
• and
• indicating that the spatial merging candidate is not available when the SMD position is in the first PMER.