Log Message:
Version 2.5

Encoder enhancements
--------------------
1. Improved grain handling with :option:`--tune` grain option by throttling VBV \ 
operations to limit QP jumps.
2. Frame threads are now decided based on number of threads specified in the \ 
:option:`--pools`, as opposed to the number of hardware threads available. The \ 
mapping was also adjusted to improve quality of the encodes with minimal impact \ 
to performance.
3. CSV logging feature (enabled by :option:`--csv`) is now part of the library; \ 
it was previously part of the x265 application. Applications that integrate \ 
libx265 can now extract frame level statistics for their encodes by exercising \ 
this option in the library.
4.  Globals that track min and max CU sizes, number of slices, and other \ 
parameters have now been moved into instance-specific variables. Consequently, \ 
applications that invoke multiple instances of x265 library are no longer \ 
restricted to use the same settings for these parameter options across the \ 
multiple instances.
5. x265 can now generate a seprate library that exports the HDR10+ parsing API. \ 
Other libraries that wish to use this API may do so by linking against this \ 
library. Enable ENABLE_HDR10_PLUS in CMake options and build to generate this \ 
library.
6. SEA motion search receives a 10% performance boost from AVX2 optimization of \ 
its kernels.
7. The CSV log is now more elaborate with additional fields such as PU \ 
statistics, average-min-max luma and chroma values, etc. Refer to documentation \ 
of :option:`--csv` for details of all fields.
8. x86inc.asm cleaned-up for improved instruction handling.

API changes
-----------
1. New API x265_encoder_ctu_info() introduced to specify suggested partition \ 
sizes for various CTUs in a frame. To be used in conjunction with \ 
:option:`--ctu-info` to react to the specified partitions appropriately.
2. Rate-control statistics passed through the x265_picture object for an \ 
incoming frame are now used by the encoder.
3. Options to scale, reuse, and refine analysis for incoming analysis shared \ 
through the x265_analysis_data field in x265_picture for runs that use \ 
:option:`--analysis-reuse-mode` load; use options :option:`--scale`, \ 
:option:`--refine-mv`, :option:`--refine-inter`, and :option:`--refine-intra` to \ 
explore.
4. VBV now has a deterministic mode. Use :option:`--const-vbv` to exercise.

Bug fixes
---------
1. Several fixes for HDR10+ parsing code including incompatibility with \ 
user-specific SEI, removal of warnings, linking issues in linux, etc.
2. SEI messages for HDR10 repeated every keyint when HDR options \ 
(:option:`--hdr-opt`, :option:`--master-display`) specified.