  This paper investigates the energy consumption of video encoding for high
dynamic range videos. Specifically, we compare the energy consumption of the
compression process using 10-bit input sequences, a tone-mapped 8-bit input
sequence at 10-bit internal bit depth, and encoding an 8-bit input sequence
using an encoder with an internal bit depth of 8 bit. We find that linear
scaling of the luminance and chrominance values leads to degradations of the
visual quality, but that significant encoding complexity and thus encoding
energy can be saved. An important reason for this is the availability of vector
instructions, which are not available for the 10-bit encoder. Furthermore, we
find that at sufficiently low target bitrates, the compression efficiency at an
internal bit depth of 8 bit exceeds the compression efficiency of regular
10-bit encoding.
