Philipp Hancke aa6cedb39c Add a box filter to ScaleUV
kFilterBox only had 1/2 and 1/4 fast paths. Everything else fell
through to ScaleUVSimple and point sampled, so NV12 chroma was
unfiltered where I420 was not. 13.6 dB against 50.2 dB at 3x.

ScaleUVBox mirrors ScalePlaneBox. Row accumulation reuses ScaleAddRow
and its SIMD variants, since summing is position wise and an
interleaved row is just src_cols * 2 samples. Only the column pass,
which sums U and V at a stride of 2, is new.

Output is now byte identical to the I420 path. Tests compare against
ScalePlane rather than C against SIMD, which is what missed this.

Bug: libyuv:564129034
Change-Id: I26221f5435dbfc845ad2fc13aa347ef56ccf7bc6
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/8426668
Reviewed-by: richard winterton <rrwinterton@gmail.com>
Reviewed-by: Frank Barchard <fbarchard@google.com>
2026-10-02 15:37:21 -07:00
build_overrides [vpython] Migrate .vpython3 to vpython.toml 2026-09-18 00:28:26 -07:00
docs convert, scale: Add P010/P210/P410 convert paths and NV16/NV24/Px10 scale 2026-09-23 20:43:22 -07:00
include Compare AVX512BW and AVX2, intrinsics for Visual C and ROWWIN 2026-10-02 15:30:05 -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 Add a box filter to ScaleUV 2026-10-02 15:37:21 -07:00
tools_libyuv Remove libyuv dependency on base/ 2025-01-08 09:04:21 -08:00
unit_test Add a box filter to ScaleUV 2026-10-02 15:37:21 -07:00
util [libyuv] Fix RISC-V CMake/GN/Bazel builds and C compiler driver linking 2026-09-28 10:59:30 -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] 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] Fix RISC-V CMake/GN/Bazel builds and C compiler driver linking 2026-09-28 10:59:30 -07:00
BUILD.gn [libyuv] Fix RISC-V CMake/GN/Bazel builds and C compiler driver linking 2026-09-28 10:59:30 -07:00
CM_linux_packages.cmake Use grep extended regex for version 2024-11-13 02:11:17 +00:00
CMakeLists.txt [libyuv] Fix RISC-V CMake/GN/Bazel builds and C compiler driver linking 2026-09-28 10:59:30 -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 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 [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] 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 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.