High-dynamic-range (HDR) technology is an emerging video technology that allows displays to produce a higher range of luminance to better approximate the range of brightness perceived by the human eye. However, during the transition to this new technology, not all consumer devices will support the full range of luminance values offered by HDR. In order to also support these devices with lower dynamic ranges, content providers have to supply multiple dynamic range versions to provide the best experience to all viewers. This means that the processing cost to compress these versions will be multiplied by the number of versions. As a solution, this paper proposes a simultaneous encoder based on high efficiency video coding. This encoder reuses parts of the coding information generated during compression of an HDR video to accelerate the encoding of a low-dynamic-range (LDR) version of the same video. The proposed method speeds up the encoder 299 times with a bit rate increase of 12.4% compared to a non-accelerated encode of the LDR version. This is more than 90 times faster compared to state-of-the-art fast encoding algorithms and allows simultaneous encoding of the two versions for approximately the computational cost of a single encoder(1).