x265 0.8 is a regularly scheduled feature release. Binaries for 8+17 are available here: Our builds

New in 0.8

* 4:4:4 internal color space is now supported. Input pictures must also be 4:4:4, 8 or 10bit. We advise to disable weightp with 4:4:4. Note that since the HEVC Range Extensions are not finalized, this feature should be considered highly experimental. Our output streams may not be compliant with the final spec.
* Improved VBV. x265 will now do mid-frame QP adjustments in order to better meet the bit target. Further improvements will be in the next release (partial slice re-encode when bit budget is very tight).
* FPS is finally handled in a sane fashion. It may be configured as a rational number (numerator/denominator) or as a float. The frame rate is now signaled in the VPS header for use by the decoder.
* VUI signaling is now exposed in the x265_param structure and in the x265 CLI. The exact params and CLI options should be considered experimental at this point, and are liable to change.
* Near full ASM coverage of the 8bit build, and much more 10bit assembly than the previous release. All of the interpolation and intra primitives that were written with SIMD intrinsics have been replaced with assembly routines.
* Input pixel bit depth is now decoupled from the internal bit depth. An 8bpp build and a 16bpp build of x265 will both be able to encode 8bit or 10bit or 16bit raw video streams. The encoder will shift and mask pixels as necessary to get them to the internal depth.
* Motion compensated weight analysis. This will be further improved in the next release.

CLI changes since 0.7
# Added #
–scenecut
-i/–min-keyint
–vui
–sar
–overscan
–videoformat
–range
–colorprim
–transfer
–colormatrix
–chromaloc
–[no-]fieldseq
–[no-]framefieldinfo
–crop-rect
–timinginfo
–nal-hrd
–bitstreamrestriction
–subpichrd

Replaced options, to sync with x264

–refresh is now –[no]open-gop –frame-skip is now –seek -i/–keyint is now -I/–keyint (short opt case change)

Upcoming work

The next release will focus on improving all of the recently added features, particularly VBV and adaptive quant, and focusing heavily on improving perceptive visual quality.