on the amplitude of a single sample. A sample is categorized by its amplitude into one of 32 bands (histogram bins). Offsets are specified for four consecutive of the 32 bands, because in flat areas which are prone to banding artifacts, sample amplitudes tend to be clustered in a small range. The SAO filter was designed to increase picture quality, reduce banding artifacts, and reduce ringing artifacts. Range extensions Range extensions in MPEG are additional profiles, levels, and techniques that support needs beyond consumer video playback: Profiles supporting bit depths beyond 10, and differing luma/chroma bit depths. Intra profiles for when file size is much less important than random-access decoding speed. Still Picture profiles, forming the basis of High Efficiency Image File Format, without any limit on the picture size or complexity (level 8.5). Unlike all other levels, no minimum decoder capacity is required, only a best-effort with reasonable fallback. Within these new profiles came enhanced coding features, many of which support efficient screen encoding or high-speed processing: Persistent Rice adaptation, a general optimization of entropy coding. Higher precision weighted prediction at high bit depths. Cross-component prediction, allowing the imperfect YCbCr color decorrelation to let the luma (or G) match set the predicted chroma (or R/B) matches, which results in up to 7% gain for YCbCr 4:4:4 and up to 26% for RGB video. Particularly useful for screen coding. Intra smoothing control, allowing the encoder to turn smoothing on or off per-block, instead of per-frame. Modifications of transform skip: Residual DPCM (RDPCM), allowing more-optimal coding of residual data if possible, vs the typical zig-zag. Block size flexibility, supporting block sizes up to 32×32 (versus only 4×4 transform skip support in version 1). 4×4 rotation, for potential efficiency. Transform skip context, enabling DCT and RDPCM blocks to carry a separate context. Extended precision processing, giving low bit-depth video slightly more accurate decoding. CABAC bypass alignment, a decoding optimization specific to High Throughput 4:4:4 16 Intra profile. HEVC version 2 adds several supplemental enhancement information (SEI) messages: Color remapping: mapping one color space to another. Knee function: hints for converting between dynamic ranges, particularly from HDR to SDR. Mastering display color volume Time code, for archival purposes Screen content coding extensions Additional coding tool options have been added in the March 2016 draft of the screen content coding (SCC) extensions: Adaptive color transform. Adaptive motion vector resolution. Intra block copying. Palette mode.