George Steed 2dd4257364 AArch64: Fix HalfMergeUVRow_SVE2 average calculation
The existing SVE2 path only computes the average for a pair of input
values instead of groups of four as done in the Neon implementation.

The average of two values must be retained for the final odd element if
present. Existing code just handles this by falling back to the C
implementation, so mirror that for SVE2 as well.

Reduction in time taken relative to the existing Neon code, the SVE2
code remains faster even with the correct averaging:

       Cortex-A510: -12.66%
     Lumex C1-Nano:  -6.38%
       Cortex-A720:  -9.73%
      Lumex C1-Pro:  +0.99%
         Cortex-X4:  -3.05%
    Lumex C1-Ultra: -18.98%

Bug: 546962730
Change-Id: I7ab348e64a9d079b81d070cea5fd575243b037d2
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/8252281
Reviewed-by: Wan-Teh Chang <wtc@google.com>
Reviewed-by: Justin Green <greenjustin@google.com>
Commit-Queue: Wan-Teh Chang <wtc@google.com>
2026-09-11 05:56:04 -07:00
build_overrides [tracing] Remove enable_base_tracing 2025-05-15 01:22:38 -07:00
docs Enable RVV support in CMake and Bazel for RISC-V targets 2026-09-04 13:20:27 -07:00
include AArch64: Fix HalfMergeUVRow_SVE2 average calculation 2026-09-11 05:56:04 -07:00
infra/config Use default xcode version in libyuv 2025-11-24 07:54:14 -08:00
riscv_script Support RVV v0.12 intrinsics for row_rvv.cc & scale_rvv.cc 2024-06-17 18:01:49 +00:00
source AArch64: Fix HalfMergeUVRow_SVE2 average calculation 2026-09-11 05:56:04 -07:00
tools_libyuv Remove libyuv dependency on base/ 2025-01-08 09:04:21 -08:00
unit_test Make loops iterate over arrays using size_t index 2026-09-09 10:56:48 -07:00
util [libyuv] Keep LIBYUV_API in basic_types.h and remove legacy types and bool macros 2026-08-28 08:32:19 -07:00
.clang-format clang-format libyuv 2016-11-07 17:37:23 -08:00
.gitignore DetilePlane and unittest for NEON 2022-01-31 20:05:55 +00:00
.gn Set use_siso=true by default in .gn 2025-06-23 23:50:32 -07:00
.vpython3 [libyuv] Bump vpython from 3.8 to 3.11 2025-09-03 12:22:19 -07:00
Android.bp [libyuv] Update build files with missing sources and sort lists 2026-09-03 11:02:07 -07:00
Android.mk [libyuv] Update build files with missing sources and sort lists 2026-09-03 11:02:07 -07:00
AUTHORS Fix same-width vertical point upsampling 2026-08-24 19:28:50 -07:00
BUILD.bazel [libyuv] Use Armv8.5-A architecture flags for SME and SVE2 build targets 2026-09-09 09:17:24 -07:00
BUILD.gn [libyuv] Use Armv8.5-A architecture flags for SME and SVE2 build targets 2026-09-09 09:17:24 -07:00
CM_linux_packages.cmake Use grep extended regex for version 2024-11-13 02:11:17 +00:00
CMakeLists.txt [libyuv] Use Armv8.5-A architecture flags for SME and SVE2 build targets 2026-09-09 09:17:24 -07:00
codereview.settings [infra] remove no longer supported git cl upload setting. 2021-04-28 12:47:52 +00:00
DEPS [DEPS] Add CPython CIPD package for hermetic Python toolchain 2026-08-19 20:31:30 -07:00
DIR_METADATA Move metadata in OWNERS files to DIR_METADATA files 2021-02-09 19:34:43 +00:00
download_vs_toolchain.py Update pylintrc to a pep-8 like style 2024-12-18 05:38:56 -08:00
GEMINI.md GEMINI.md: Update Arm wording and guidance 2026-08-18 11:21:14 -07:00
libyuv.bzl [libyuv] Simplify RVV configuration in BUILD.bazel and libyuv.bzl 2026-09-08 17:50:17 -07:00
libyuv.gni row_win.cc rewrite into intrinsics 2026-04-15 19:53:16 -07:00
libyuv.gyp Stop setting --dynamic-linker for target_os="android" 2026-05-27 04:34:07 -07:00
libyuv.gypi [libyuv] Update build files with missing sources and sort lists 2026-09-03 11:02:07 -07:00
LICENSE Update Copyright notice to follow new chromium conventions. 2012-08-08 19:04:24 +00:00
linux.mk Deprecate MIPS and MSA support. 2025-10-16 12:20:40 -07:00
OWNERS Remove magjed from OWNERS 2026-08-24 10:43:21 -07:00
PATENTS LibYuv: Adding PATENT and LICENSE files 2011-10-25 16:15:49 +00:00
PRESUBMIT.py Update pylintrc to a pep-8 like style 2024-12-18 05:38:56 -08:00
public.mk use unix line endings 2018-06-20 23:19:59 +00:00
pylintrc Update pylintrc to a pep-8 like style 2024-12-18 05:38:56 -08:00
README.chromium [libyuv] Add SwapUVRow_AVX2 and NV12ToNV21 2026-09-04 12:23:24 -07:00
README.md Update README.md and environment_variables.md for Arm 2024-09-20 00:29:33 +00:00
winarm.mk NV12 Copy, include scale_uv.h 2020-12-08 18:54:16 +00:00
WORKSPACE.bazel Add Bazel build support 2026-04-15 18:20:26 -07:00

libyuv is an open source project that includes YUV scaling and conversion functionality.

  • Scale YUV to prepare content for compression, with point, bilinear or box filter.
  • Convert to YUV from webcam formats for compression.
  • Convert to RGB formats for rendering/effects.
  • Rotate by 90/180/270 degrees to adjust for mobile devices in portrait mode.
  • Optimized for SSSE3/AVX2 on x86/x64.
  • Optimized for Neon/SVE2/SME on Arm.
  • Optimized for MSA on Mips.
  • Optimized for RVV on RISC-V.

Development

See Getting started for instructions on how to get started developing.

You can also browse the docs directory for more documentation.