mirror of
https://chromium.googlesource.com/libyuv/libyuv
synced 2025-12-06 16:56:55 +08:00
This re-lands commit ba0bba5b2b7e38c9365a5d152b4efa0458863213.
Now with additional #ifdef __linux__ guards to avoid compiling
Linux-specific code on non-Linux platforms. Non-linux feature detection
will be added in a separate patch.
Using getauxval(AT_HWCAP{,2}) has the advantage of also working under
emulation where faking /proc/cpuinfo is not supported.
For the Chromium sandbox, getauxval is supported since API version 18.
The minimum supported API version at time of writing is 21 so we should
be able to use getauxval unconditionally. On the off-chance the call
fails it will return 0 and we will correctly fall-back to using only
Neon.
If we want to read the current CPU implementer or part number we could
do this by checking HWCAP_CPUID and then reading MIDR_EL1. This will
cause a kernel trap to emulate the EL1 read but should still be a lot
faster than reading the whole of /proc/cpuinfo.
Bug: libyuv:980
Change-Id: I8ae103ea7e32ef44db72f3c9896417bfe97ff5c5
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/5465590
Reviewed-by: Frank Barchard <fbarchard@chromium.org>
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| build_overrides | ||
| docs | ||
| include | ||
| infra/config | ||
| riscv_script | ||
| source | ||
| tools_libyuv | ||
| unit_test | ||
| util | ||
| .clang-format | ||
| .gitignore | ||
| .gn | ||
| .vpython | ||
| .vpython3 | ||
| Android.bp | ||
| Android.mk | ||
| AUTHORS | ||
| BUILD.gn | ||
| CM_linux_packages.cmake | ||
| CMakeLists.txt | ||
| codereview.settings | ||
| DEPS | ||
| DIR_METADATA | ||
| download_vs_toolchain.py | ||
| libyuv.gni | ||
| libyuv.gyp | ||
| libyuv.gypi | ||
| LICENSE | ||
| linux.mk | ||
| OWNERS | ||
| PATENTS | ||
| PRESUBMIT.py | ||
| public.mk | ||
| pylintrc | ||
| README.chromium | ||
| README.md | ||
| winarm.mk | ||
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 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.