By Pradeep Ramachandran
Encoder enhancements
- HDR10+ supported. Dynamic metadata may be either supplied as a bitstream via the userSEI field of x265_picture, or as a json jile that can be parsed by x265 and inserted into the bitstream; use
--dhdr10-infoto specify json file name, and--dhdr10-optto enable optimization of inserting tone-map information only at IDR frames, or when the tone map information changes. - Lambda tables for 8, 10, and 12-bit encoding revised, resulting in significant enhancement to subjective visual quality.
- Enhanced HDR10 encoding with HDR-specific QP optimzations for chroma, and luma planes of WCG content enabled; use
--hdr-optto activate. - Ability to accept analysis information from other previous encodes (that may or may not be x265), and selectively reuse and refine analysis for encoding subsequent passes enabled with the
--refine-leveloption. - Slow and veryslow presets receive a 20% speed boost at iso-quality by enabling the
--limit-tuoption. - The bitrate target for x265 can now be dynamically reconfigured via the reconfigure API.
- Performance optimized SAO algorithm introduced via the
--limit-saooption; seeing 10% speed benefits at faster presets.
API changes
- x265_reconfigure API now also accepts rate-control parameters for dynamic reconfiguration.
- Several additions to data fields in x265_analysis to support
--refine-level: see x265.h for more details.
Bug fixes
- Avoid negative offsets in x265 lambda2 table with SAO enabled.
- Fix mingw32 build error.
- Seek now enabled for pipe input, in addition to file-based input
- Fix issue of statically linking core-utils not working in linux.
- Fix visual artifacts with
--multi-pass-opt-distortionwith VBV. - Fix bufferFill stats reported in csv.