Release date – 15th February, 2017.
- New SSIM-based RD-cost computation for improved visual quality, and efficiency; use
- Multi-pass encoding can now share analysis information from prior passes (in addition to rate-control information) to improve performance and quality of subsequent passes; to your multi-pass command-lines that use the
--multi-pass-opt-distortionto share distortion information, and
--multi-pass-opt-analysisto share other analysis information.
- A dedicated thread pool for lookahead can now be specified with
- option:–dynamic-rd dynamically increase analysis in areas where the bitrate is being capped by VBV; works for both CRF and ABR encodes with VBV settings.
- The number of bits used to signal the delta-QP can be optimized with the
--opt-cu-delta-qpoption; found to be useful in some scenarios for lower bitrate targets.
- Experimental feature option:–aq-motion adds new QP offsets based on relative motion of a block with respect to the movement of the frame.
- Reconfigure API now supports signalling new scaling lists.
- x265 application’s csv functionality now reports time (in milliseconds) taken to encode each frame.
--strict-cbrenables stricter bitrate adherence by adding filler bits when achieved bitrate is lower than the target; earlier, it was only reacting when the achieved rate was higher.
--hdrcan be used to ensure that max-cll and max-fall values are always signaled (even if 0,0).
- Fixed incorrect HW thread counting on MacOS platform.
- Fixed scaling lists support for 4:4:4 videos.
- Inconsistent output fix for
--opt-qp-pssby removing last slice’s QP from cost calculation.
- VTune profiling (enabled using ENABLE_VTUNE CMake option) now also works with 2017 VTune builds.