Frank Barchard f310cb6ce1 [libyuv] Pilot OpenMP support for row processing
Add SetMaxThreads() and GetMaxThreads() APIs (with LIBYUV_NUM_THREADS
environment variable override, defaulting to half of logical cores
capped at 8 when built with -fopenmp).

Enable OpenMP parallel row processing for large frames (>= 1280x720)
in I420ToARGBMatrix and CopyPlane (including reshaping coalesced
contiguous planes across threads), and configure thread counts for
ComputeHammingDistance, ComputeSumSquareError, and CalcFrameSsim.

1280x720 Benchmarks (ms):
Benchmark          Reps    1T    2T    4T    8T  Speedup
--------------------------------------------------------
I420ToARGB_Opt     1000   272   162    88    60    4.53x
CopyPlane_Opt      1000    57    42    19    14    4.07x
BenchmarkPsnr_Opt  1000    92    76    56    34    2.71x
BenchmarkSsim_Opt   100   518   241   147    89    5.82x

R=rrwinterton@gmail.com

Bug: none
Test: libyuv_unittest --gtest_filter=*TestSetMaxThreads*:*I420ToARGB_Opt*:*CopyPlane_Opt*:*Ssim*
Change-Id: I5ca9a2b8c68eaac870da6353c51306930d015c3a
CONV=a7f09b98-93ab-4652-a8eb-8d9551361f61
TAG=agy
2026-10-19 15:17:30 -07:00
build_overrides [vpython] Migrate .vpython3 to vpython.toml 2026-09-18 00:28:26 -07:00
docs [libyuv] Pilot OpenMP support for row processing 2026-10-19 15:17:30 -07:00
include [libyuv] Pilot OpenMP support for row processing 2026-10-19 15:17:30 -07:00
infra/config Use default xcode version in libyuv 2025-11-24 07:54:14 -08:00
riscv_script [libyuv] Fix RISC-V CMake/GN/Bazel builds and C compiler driver linking 2026-09-28 10:59:30 -07:00
source [libyuv] Pilot OpenMP support for row processing 2026-10-19 15:17:30 -07:00
tools_libyuv Remove libyuv dependency on base/ 2025-01-08 09:04:21 -08:00
unit_test [libyuv] Pilot OpenMP support for row processing 2026-10-19 15:17:30 -07:00
util [libyuv] Pilot OpenMP support for row processing 2026-10-19 15:17:30 -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 [build] Use hermetic python3 for script_executable in .gn 2026-09-28 06:02:39 -07:00
Android.bp [libyuv] Add Qualcomm Hexagon HVX SIMD support 2026-10-19 14:16:18 -07:00
Android.mk [libyuv] Add Qualcomm Hexagon HVX SIMD support 2026-10-19 14:16:18 -07:00
AUTHORS Fix same-width vertical point upsampling 2026-08-24 19:28:50 -07:00
BUILD.bazel [libyuv] Add WASM SIMD128 and Relaxed SIMD for RAWToRGB24Row 2026-10-05 17:45:41 -07:00
BUILD.gn [libyuv] Add Qualcomm Hexagon HVX SIMD support 2026-10-19 14:16:18 -07:00
CM_linux_packages.cmake Use grep extended regex for version 2024-11-13 02:11:17 +00:00
CMakeLists.txt [libyuv] Add Qualcomm Hexagon HVX SIMD support 2026-10-19 14:16:18 -07:00
codereview.settings [infra] remove no longer supported git cl upload setting. 2021-04-28 12:47:52 +00:00
DEPS [build] Use hermetic python3 for script_executable in .gn 2026-09-28 06:02:39 -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 [libyuv] Add Qualcomm Hexagon HVX SIMD support 2026-10-19 14:16:18 -07:00
libyuv.bzl [libyuv] Simplify RVV configuration in BUILD.bazel and libyuv.bzl 2026-09-08 17:50:17 -07:00
libyuv.gni [libyuv] Fix RISC-V CMake/GN/Bazel builds and C compiler driver linking 2026-09-28 10:59:30 -07:00
libyuv.gyp Stop setting --dynamic-linker for target_os="android" 2026-05-27 04:34:07 -07:00
libyuv.gypi [libyuv] Add Qualcomm Hexagon HVX SIMD support 2026-10-19 14:16:18 -07:00
LICENSE Update Copyright notice to follow new chromium conventions. 2012-08-08 19:04:24 +00:00
linux.mk [libyuv] Add Qualcomm Hexagon HVX SIMD support 2026-10-19 14:16:18 -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 ARGBToRGB24 AVX512 with tail masking 2026-09-29 16:15:44 -07:00
README.md Update README.md and environment_variables.md for Arm 2024-09-20 00:29:33 +00:00
vpython.toml [vpython] Migrate .vpython3 to vpython.toml 2026-09-18 00:28:26 -07:00
vpython.toml.uv.lock [vpython] Migrate .vpython3 to vpython.toml 2026-09-18 00:28:26 -07:00
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.