Take it from someone who has backpacked the length and breadth of Africa: it's big, slow, exciting and infuriating in equal measure.
引用一位背着行囊已经踏遍非洲山山水水的旅行者的话：广袤、缓慢、激动人心、使人恼怒，非洲都兼而有之。
2
I determined they should come about as they pleased for me; and though it was a tiresomely slow process, I began to rejoice at length in a faint dawn of its progress: as I thought at first.
The three-step search method is a commonly used fast motion estimation algorithm, but its initial step length is too big, thus the estimation effect of slow motion sequence is not so satisfactory.