1. A method of decoding a bitstream, comprising: receiving a bitstream at a decoder; decoding said bitstream with said decoder into color values and metadata items indicating information about adaptive post-processing operations to be performed by said decoder; performing, with said decoder, one or more high dynamic range (HDR) adaptation operations on said color values based on said metadata items; and performing, with said decoder, one or more fixed post-processing operations to reconstruct an HDR video from said color values, wherein said one or more HDR adaptation operations convert said color values into a format expected by said one or more fixed post-processing operations.