1.配置
qt的pro配置文件

#TensorRT
#头文件路径
INCLUDEPATH += /usr/include/x86_64-linux-gnu
#查找：sudo find / -name "NvInfer.h"#链接TensorRT的库文件
LIBS += -L/lib/x86_64-linux-gnu -lnvinfer
LIBS += -L/lib/x86_64-linux-gnu -lnvonnxparser
LIBS += -L/lib/x86_64-linux-gnu -lnvinfer_plugin
#查找方式ldconfig -p | grep libnvinfer

2.构建模型
【参考官网】https://developer.nvidia.com/zh-cn/blog/tensorrt-c-interface-cn/

void build_model()
{IBuilder* builder = createInferBuilder(logger);//【创建网络定义】uint32_t flag = 1U <<static_cast<uint32_t>(NetworkDefinitionCreationFlag::kEXPLICIT_BATCH);INetworkDefinition* network = builder->createNetworkV2(flag);//【创建网络定义】IParser*  parser = createParser(*network, logger);const char* modelFile="";parser->parseFromFile(modelFile,static_cast<int32_t>(ILogger::Severity::kWARNING));for(int32_t i = 0; i < parser->getNbErrors(); ++i){std::cout << parser->getError(i)->desc() << std::endl;}//【构建配置】IBuilderConfig* config = builder->createBuilderConfig();config->setMemoryPoolLimit(MemoryPoolType::kWORKSPACE, 1U << 20);IHostMemory*  serializedModel = builder->buildSerializedNetwork(*network, *config);delete parser;delete network;delete config;delete builder;//【保存模型】....delete serializedModel;
}

2.1 构建模型
构建模型可以进一步细化

bool constructNetwork(nvinfer1::IBuilder *builder, nvinfer1::INetworkDefinition *network, nvinfer1::IBuilderConfig *config, nvonnxparser::IParser *parser)
{// 解析onnx文件if (!parser->parseFromFile(modelFile,static_cast<int32_t>(ILogger::Severity::kWARNING))){return false;}if (RUN_FP16){config->setFlag(nvinfer1::BuilderFlag::kFP16);}if (RUN_INT8){config->setFlag(nvinfer1::BuilderFlag::kINT8);}return true;
}

2.2 保存模型

	// 保存plan文件数据bool saveEngineFile(nvinfer1::IHostMemory *data){std::ofstream file;file.open(m_engine_file, std::ios::binary | std::ios::out);cout << "writing engine file..." << endl;file.write((const char *)data->data(), data->size());cout << "save engine file done" << endl;file.close();return true;}nvinfer1::ICudaEngine *m_engine;trt_model_stream = m_engine->serialize();nvinfer1::IHostMemory *data = builder->buildSerializedNetwork(*network,*config);saveEngineFile(data);

3.运行时
直接加载Engine

nvinfer1::ICudaEngine *m_engine;
bool loadEngineFromFile()
{int length = 0; // 记录data的长度std::unique_ptr<char[]> data = readEngineFile(length);nvinfer1::IRuntime *runtime = nvinfer1::createInferRuntime(sample::gLogger.getTRTLogger());m_engine = runtime->deserializeCudaEngine(data.get(), length);if (!m_engine){std::cout << "Failed to create engine" << std::endl;return false;}return true;
}

运行推理应该至少包含以下几步

1. 创建nvinfer1::IExecutionContext
2. 为输入和输出创建空间：用于后面宿主机和设备机数据的传递
3. 推理：图片处理+数据传递+推理
4. 后处理：后处理每种问题各不相同

3.2.1 创建nvinfer1

    nvinfer1::IExecutionContext *context = m_engine->createExecutionContext();assert(context != nullptr);

3.2.2 为输入和输出创建空间

int nbBindings = m_engine->getNbBindings();
assert(nbBindings == 2); // 输入和输出，一共是2个// 为输入和输出创建空间
void *buffers[2];                 // 待创建的空间  为指针数组
std::vector<int64_t> buffer_size; // 要创建的空间大小
buffer_size.resize(nbBindings);
for (int i = 0; i < nbBindings; i++)
{nvinfer1::Dims dims = m_engine->getBindingDimensions(i);    // (3, 224, 224)  (1000)nvinfer1::DataType dtype = m_engine->getBindingDataType(i); // 0, 0 也就是两个都是kFloat类型// std::cout << static_cast<int>(dtype) << endl;int64_t total_size = volume(dims) * 1 * getElementSize(dtype);buffer_size[i] = total_size;CHECK(cudaMalloc(&buffers[i], total_size));
}

3.2.3 推理

// 将输入传递到GPUCHECK(cudaMemcpyAsync(buffers[0], cur_input.data(), buffer_size[0], cudaMemcpyHostToDevice, stream));// 异步执行t_start = std::chrono::high_resolution_clock::now();context->enqueueV2(&buffers[0],stream,nullptr);// 输出传回给CPUCHECK(cudaMemcpyAsync(out, buffers[1], buffer_size[1], cudaMemcpyDeviceToHost, stream));cudaStreamSynchronize(stream);