in the NV_ENC_PIC_PARAMS struct the documentation for the meExternalHints says:
“For H264 and Hevc, Specifies the pointer to ME external hints for the current frame. The size of ME hint buffer should be equal to number of macroblocks * the total number of candidates per macroblock.
The total number of candidates per MB per direction = 1meHintCountsPerBlock[Lx].numCandsPerBlk16x16 + 2meHintCountsPerBlock[Lx].numCandsPerBlk16x8 + 2meHintCountsPerBlock[Lx].numCandsPerBlk8x8
+ 4meHintCountsPerBlock[Lx].numCandsPerBlk8x8. For frames using bidirectional ME , the total number of candidates for single macroblock is sum of total number of candidates per MB for each direction (L0 and L1)”
in the calculation numCandsPerBlk8x8 is used twice and numCandsPerBlk8x16 is not used at all - i think this is a mistake??