High-dynamic-range (HDR) video streams have been delivered through high-efficiency video coding (HEVC). HDR video tone mapping is required additionally but is operated separately to adjust the content’s dynamic range for each display device. HDR video tone mapping and HEVC encoding share common computational processes for spatial and temporal coherence in a video stream; however, they have been developed and implemented independently with their own computational budgets. In this work, we propose a practical HDR video tone mapping method that combines two overlapping computational blocks in HDR video tone-mapping and HEVC compression frameworks with an objective to achieve real-time HDR video tone mapping. We utilize precomputed coding blocks and motion vectors so as to achieve spatial and temporal coherence of HDR video tone-mapping in the decoding stage, even without introducing a substantial computational cost. Results demonstrate that our method can achieve real-time performance without compromising the video quality, which is highly comparable to state-of-the-art video tone-mapping methods.