Linux测试处理fps为30、1920*1080、一分钟的视频性能
前置条件
模拟fps为30、1920*1080、一分钟的视频
项目CMakeLists.txt
cmake_minimum_required(VERSION 3.30)
project(testOpenGl)
set(CMAKE_CXX_STANDARD 11)
add_executable(testOpenGl main.cpp
testOpenCl.cpp
testOpenCl.h
TestCpp.cpp
TestCpp.h
TestCppThread.cpp
TestCppThread.h
TestSIMD.cpp
TestSIMD.h)
# 查找OpenCL
find_package(OpenCL REQUIRED)
# 链接OpenCl库
target_include_directories(testOpenGl PRIVATE ${OpenCL_INCLUDE_DIRS})
target_link_libraries(testOpenGl PRIVATE ${OpenCL_LIBRARIES})
# 检测SIMD支持并添加编译选项
include(CheckCXXCompilerFlag)
check_cxx_compiler_flag("-mavx" COMPILER_SUPPORTS_AVX)
check_cxx_compiler_flag("-mavx2" COMPILER_SUPPORTS_AVX2)
if(COMPILER_SUPPORTS_AVX2)
target_compile_options(testOpenGl PRIVATE -mavx2)
elseif (COMPILER_SUPPORTS_AVX)
target_compile_options(testOpenGl PRIVATE -mavx)
else ()
message(FATAL_ERROR "AVX or AVX2 is not supported by compiler")
endif ()
C++代码
//
// Created by lai on 2025/1/17.
//
#include "TestCpp.h"
#include <iostream>
#include <vector>
#include <random>
#include <chrono>
// 灰度转换函数
void to_gray(const std::vector<unsigned char>& input, std::vector<unsigned char>& output, int width, int height) {
for (int i = 0; i < width * height; ++i) {
int offset = i * 3; // RGB 分量
unsigned char r = input[offset];
unsigned char g = input[offset + 1];
unsigned char b = input[offset + 2];
// 灰度公式
output[i] = static_cast<unsigned char>(0.299f * r + 0.587f * g + 0.114f * b);
}
}
void TestCpp::runTest() {
const int width = 1920; // 视频宽度
const int height = 1080; // 视频高度
const int fps = 30; // 帧率
const int duration = 60; // 视频持续时间(秒)
const int frameCount = fps * duration; // 总帧数
// 模拟视频帧数据:随机生成每帧的 RGB 数据
std::vector<unsigned char> inputFrame(width * height * 3);
std::vector<unsigned char> outputFrame(width * height);
std::random_device rd;
std::mt19937 gen(rd());
std::uniform_int_distribution<> dis(0, 255);
// 开始处理
auto startTime = std::chrono::high_resolution_clock::now();
for (int frame = 0; frame < frameCount; ++frame) {
// 随机生成模拟的 RGB 数据
for (auto& pixel : inputFrame) {
pixel = dis(gen);
}
// 调用灰度转换函数
to_gray(inputFrame, outputFrame, width, height);
// 打印进度
if (frame % 30 == 0) {
std::cout << "Processed frame: " << frame + 1 << "/" << frameCount << std::endl;
}
}
auto endTime = std::chrono::high_resolution_clock::now();
double elapsedTime = std::chrono::duration<double>(endTime - startTime).count();
// 打印处理时间
std::cout << "Processed " << frameCount << " frames in " << elapsedTime << " seconds." << std::endl;
std::cout << "Average time per frame: " << (elapsedTime / frameCount) << " seconds." << std::endl;
}
C++多线程
//
// Created by lai on 2025/1/17.
//
#include "TestCppThread.h"
#include <iostream>
#include <vector>
#include <random>
#include <chrono>
#include <thread>
// 灰度转换函数,每个线程处理一部分图像
void to_gray_chunk(const std::vector<unsigned char>& input, std::vector<unsigned char>& output, int width, int height, int start, int end) {
for (int i = start; i < end; ++i) {
int offset = i * 3; // RGB 分量
unsigned char r = input[offset];
unsigned char g = input[offset + 1];
unsigned char b = input[offset + 2];
// 灰度公式
output[i] = static_cast<unsigned char>(0.299f * r + 0.587f * g + 0.114f * b);
}
}
void TestCppThread::runTest() {
const int width = 1920; // 视频宽度
const int height = 1080; // 视频高度
const int fps = 30; // 帧率
const int duration = 60; // 视频持续时间(秒)
const int frameCount = fps * duration; // 总帧数
const int numThreads = std::thread::hardware_concurrency(); // 获取可用线程数
// 模拟视频帧数据:随机生成每帧的 RGB 数据
std::vector<unsigned char> inputFrame(width * height * 3);
std::vector<unsigned char> outputFrame(width * height);
std::random_device rd;
std::mt19937 gen(rd());
std::uniform_int_distribution<> dis(0, 255);
// 开始处理
auto startTime = std::chrono::high_resolution_clock::now();
for (int frame = 0; frame < frameCount; ++frame) {
// 随机生成模拟的 RGB 数据
for (auto& pixel : inputFrame) {
pixel = dis(gen);
}
// 启动多个线程来处理图像
std::vector<std::thread> threads;
int chunkSize = width * height / numThreads; // 每个线程处理的像素块大小
for (int t = 0; t < numThreads; ++t) {
int start = t * chunkSize;
int end = (t == numThreads - 1) ? (width * height) : (start + chunkSize); // 最后一个线程处理剩余的像素
threads.emplace_back(to_gray_chunk, std::cref(inputFrame), std::ref(outputFrame), width, height, start, end);
}
// 等待所有线程完成
for (auto& t : threads) {
t.join();
}
// 打印进度
if (frame % 30 == 0) {
std::cout << "Processed frame: " << frame + 1 << "/" << frameCount << std::endl;
}
}
auto endTime = std::chrono::high_resolution_clock::now();
double elapsedTime = std::chrono::duration<double>(endTime - startTime).count();
// 打印处理时间
std::cout << "Processed " << frameCount << " frames in " << elapsedTime << " seconds." << std::endl;
std::cout << "Average time per frame: " << (elapsedTime / frameCount) << " seconds." << std::endl;
}
CPU版本的Opencl
cmake中添加
# 查找OpenCL
find_package(OpenCL REQUIRED)
# 链接OpenCl库
target_include_directories(testOpenGl PRIVATE ${OpenCL_INCLUDE_DIRS})
target_link_libraries(testOpenGl PRIVATE ${OpenCL_LIBRARIES})
测试代码
//
// Created by lai on 2025/1/16.
//
#include "testOpenCl.h"
#include <chrono>
#include <CL/cl.h>
#include <iostream>
#include <vector>
#include <random>
// OpenCL 内核代码
const char* kernelSource = R"(
__kernel void to_gray(
__global unsigned char* input,
__global unsigned char* output,
const int width,
const int height)
{
int id = get_global_id(0); // 每个线程处理一个像素
if (id < width * height) {
int offset = id * 3; // RGB 分量
unsigned char r = input[offset];
unsigned char g = input[offset + 1];
unsigned char b = input[offset + 2];
// 灰度公式
output[id] = (unsigned char)(0.299f * r + 0.587f * g + 0.114f * b);
}
}
)";
void TestOpenCl::runTests() {
const int width = 1920; // 视频宽度
const int height = 1080; // 视频高度
const int fps = 30; // 帧率
const int duration = 60; // 视频持续时间(秒)
const int frameCount = fps * duration; // 总帧数
// 模拟视频帧数据:随机生成每帧的 RGB 数据
std::vector<unsigned char> inputFrame(width * height * 3);
std::vector<unsigned char> outputFrame(width * height);
std::random_device rd;
std::mt19937 gen(rd());
std::uniform_int_distribution<> dis(0, 255);
// 初始化 OpenCL
cl_int err;
cl_platform_id platform;
clGetPlatformIDs(1, &platform, nullptr);
cl_device_id device;
clGetDeviceIDs(platform, CL_DEVICE_TYPE_CPU, 1, &device, nullptr);
cl_context context = clCreateContext(nullptr, 1, &device, nullptr, nullptr, &err);
cl_command_queue queue = clCreateCommandQueue(context, device, 0, &err);
cl_program program = clCreateProgramWithSource(context, 1, &kernelSource, nullptr, &err);
clBuildProgram(program, 1, &device, nullptr, nullptr, nullptr);
cl_kernel kernel = clCreateKernel(program, "to_gray", &err);
// 创建 OpenCL 缓冲区
cl_mem inputBuffer = clCreateBuffer(context, CL_MEM_READ_ONLY, inputFrame.size(), nullptr, &err);
cl_mem outputBuffer = clCreateBuffer(context, CL_MEM_WRITE_ONLY, outputFrame.size(), nullptr, &err);
// 开始处理
auto startTime = std::chrono::high_resolution_clock::now();
for (int frame = 0; frame < frameCount; ++frame) {
// 随机生成模拟的 RGB 数据
for (auto& pixel : inputFrame) {
pixel = dis(gen);
}
// 写入数据到 OpenCL 缓冲区
clEnqueueWriteBuffer(queue, inputBuffer, CL_TRUE, 0, inputFrame.size(), inputFrame.data(), 0, nullptr, nullptr);
// 设置内核参数
clSetKernelArg(kernel, 0, sizeof(cl_mem), &inputBuffer);
clSetKernelArg(kernel, 1, sizeof(cl_mem), &outputBuffer);
clSetKernelArg(kernel, 2, sizeof(int), &width);
clSetKernelArg(kernel, 3, sizeof(int), &height);
// 定义工作区大小
size_t globalSize = width * height;
// 执行内核
clEnqueueNDRangeKernel(queue, kernel, 1, nullptr, &globalSize, nullptr, 0, nullptr, nullptr);
// 读取处理后的灰度数据
clEnqueueReadBuffer(queue, outputBuffer, CL_TRUE, 0, outputFrame.size(), outputFrame.data(), 0, nullptr, nullptr);
// 打印进度
if (frame % 30 == 0) {
std::cout << "Processed frame: " << frame + 1 << "/" << frameCount << std::endl;
}
}
auto endTime = std::chrono::high_resolution_clock::now();
double elapsedTime = std::chrono::duration<double>(endTime - startTime).count();
// 打印处理时间
std::cout << "Processed " << frameCount << " frames in " << elapsedTime << " seconds." << std::endl;
std::cout << "Average time per frame: " << (elapsedTime / frameCount) << " seconds." << std::endl;
// 释放 OpenCL 资源
clReleaseMemObject(inputBuffer);
clReleaseMemObject(outputBuffer);
clReleaseKernel(kernel);
clReleaseProgram(program);
clReleaseCommandQueue(queue);
clReleaseContext(context);
}
内存对齐的SIMD指令集
cmake添加
# 检测SIMD支持并添加编译选项
include(CheckCXXCompilerFlag)
check_cxx_compiler_flag("-mavx" COMPILER_SUPPORTS_AVX)
check_cxx_compiler_flag("-mavx2" COMPILER_SUPPORTS_AVX2)
if(COMPILER_SUPPORTS_AVX2)
target_compile_options(testOpenGl PRIVATE -mavx2)
elseif (COMPILER_SUPPORTS_AVX)
target_compile_options(testOpenGl PRIVATE -mavx)
else ()
message(FATAL_ERROR "AVX or AVX2 is not supported by compiler")
endif ()
//
// Created by lai on 2025/1/17.
//
#include "TestSIMD.h"
#include <iostream>
#include <vector>
#include <random>
#include <chrono>
#include <immintrin.h> // SIMD 指令集
#include <cstdlib> // 用于posix_memalign
void to_gray_simd(const unsigned char* input, unsigned char* output, int width, int height) {
const int pixelCount = width * height;
const __m256 scale_r = _mm256_set1_ps(0.299f); // 红色通道的权重
const __m256 scale_g = _mm256_set1_ps(0.587f); // 绿色通道的权重
const __m256 scale_b = _mm256_set1_ps(0.114f); // 蓝色通道的权重
int i = 0;
for (; i <= pixelCount - 8; i += 8) {
// 加载 8 组 RGB 像素
__m256i pixel_r = _mm256_loadu_si256((__m256i*)&input[i * 3]); // 确保内存对齐
__m256i pixel_g = _mm256_loadu_si256((__m256i*)&input[i * 3 + 1]);
__m256i pixel_b = _mm256_loadu_si256((__m256i*)&input[i * 3 + 2]);
// 转换为浮点数以便计算
__m256 r_f = _mm256_cvtepi32_ps(pixel_r);
__m256 g_f = _mm256_cvtepi32_ps(pixel_g);
__m256 b_f = _mm256_cvtepi32_ps(pixel_b);
// 灰度转换公式
__m256 gray_f = _mm256_add_ps(
_mm256_add_ps(_mm256_mul_ps(r_f, scale_r), _mm256_mul_ps(g_f, scale_g)),
_mm256_mul_ps(b_f, scale_b));
// 转回整数
__m256i gray_i = _mm256_cvtps_epi32(gray_f);
// 存储结果
_mm256_storeu_si256((__m256i*)&output[i], gray_i);
}
// 处理剩余像素(非对齐部分)
for (; i < pixelCount; ++i) {
int offset = i * 3;
unsigned char r = input[offset];
unsigned char g = input[offset + 1];
unsigned char b = input[offset + 2];
output[i] = static_cast<unsigned char>(0.299f * r + 0.587f * g + 0.114f * b);
}
}
void TestSIMD::runTest() {
const int width = 1920; // 视频宽度
const int height = 1080; // 视频高度
const int fps = 30; // 帧率
const int duration = 60; // 视频持续时间(秒)
const int frameCount = fps * duration; // 总帧数
size_t size = width * height * 3 * sizeof(unsigned char);
// 模拟视频帧数据:随机生成每帧的 RGB 数据
// 使用posix_memalign分配对齐内存
unsigned char* inputFrame;
unsigned char* outputFrame;
int alignment = 32; // 使用32字节对齐
int resultInput = posix_memalign((void**)&inputFrame, alignment, size);
int resultOutput = posix_memalign((void**)&outputFrame, alignment, size);
if (resultInput != 0 || resultOutput != 0) {
std::cerr << "memory allocation failed" << std::endl;
return;
}
std::random_device rd;
std::mt19937 gen(rd());
std::uniform_int_distribution<> dis(0, 255);
// 开始处理
auto startTime = std::chrono::high_resolution_clock::now();
for (int frame = 0; frame < frameCount; ++frame) {
// 随机生成模拟的 RGB 数据
for (int i = 0; i < width * height * 3; ++i) {
inputFrame[i] = dis(gen);
}
// 使用 SIMD 转换灰度
to_gray_simd(inputFrame, outputFrame, width, height);
// 打印进度
if (frame % 30 == 0) {
std::cout << "Processed frame: " << frame + 1 << "/" << frameCount << std::endl;
}
}
auto endTime = std::chrono::high_resolution_clock::now();
double elapsedTime = std::chrono::duration<double>(endTime - startTime).count();
// 打印处理时间
std::cout << "Processed " << frameCount << " frames in " << elapsedTime << " seconds." << std::endl;
std::cout << "Average time per frame: " << (elapsedTime / frameCount) << " seconds." << std::endl;
}
结论
C++
Processed 1800 frames in 251.789 seconds.
Average time per frame: 0.139883 seconds.
C++ thread
Processed 1800 frames in 229.571 seconds.
Average time per frame: 0.12754 seconds.
CPU版本POCL的OPENCL
Processed 1800 frames in 233.25 seconds.
Average time per frame: 0.129583 seconds.
SIMD 内存对齐以后
Processed 1800 frames in 191.015 seconds.
Average time per frame: 0.106119 seconds.
SIMD的性能明显由于其他几项,但是还需要测试GPU版本的OPencl和多线程指令集优化对性能的提升