Undertone introduces several proprietary --tune parameters that override dozens of internal encoder decisions:
Undertone is not recommended for real-time or live encoding.
Undertone x265 is a of the official x265 (HEVC/H.265) encoder. While mainstream builds (like those from MulticoreWare) prioritize encoding speed or broad device compatibility, Undertone focuses on maximum compression efficiency and psychovisual retention —often at the cost of slower encoding speeds.