板端部署YOLOv8目标检测¶
Copyright © Quectel Wireless Solutions Co., Ltd. 2026. All rights reserved.
本文档基于高通Quick AI Application Builder (QAI AppBuilder)工具、wxWidgets库和YOLOv8模型，编写一个从摄像头取流，识别内容并显示到屏幕的App。
环境准备¶
执行以下命令：
sudo apt update -y
sudo apt install -y g++ make pkg-config wx3.2-headers libwxgtk3.2-dev
sudo apt install -y libopencv-core-dev libopencv-calib3d-dev libopencv-dnn-dev
sudo apt install -y libopencv-objdetect-dev libopencv-photo-dev libopencv-stitching-dev
sudo apt install -y libopencv-video-dev libgstreamer-plugins-base1.0-dev
下载 QAI AppBuilder 工具并解压到用户目录。
# 点击上面的链接下载压缩包ai-engine-direct-helper.tar，放置在~/ai-engine-direct-helper.tar# 解压cd ~
tar -xvf ai-engine-direct-helper.tar
编辑ai-engine-direct-helper/src/LibAppBuilder.cpp，移除其中的空main函数（后续编译时会用到该源文件，但不需要此main函数）。
下载 QAIRT 工具并解压到用户目录。
# 点击上面的链接下载压缩包v2.37.1.250807.zip，放置在~/v2.37.1.250807.zip# 解压cd ~
unzip v2.37.1.250807.zip
编写代码¶
创建main.cpp文件，内容如下：
#include "LibAppBuilder.hpp"#include <iostream>#include <filesystem>#include <string>#include <vector>#include <cstddef>#include <opencv2/opencv.hpp>#include <opencv2/core/utils/logger.hpp>#include <algorithm>#include <map>#include <thread>#include <wx/rawbmp.h>#include <gst/video/video-info.h>#include <wx/log.h>#include <wx/wx.h>#include <gst/gst.h>#include <gst/app/gstappsink.h>#include <wx/dcclient.h>#include <wx/thread.h>#include <chrono>#include <atomic>
namespace fs = std::filesystem;const std::string MODEL_NAME = "yolov8_det";const int IMAGE_SIZE = 640;unsigned long frameCounter = 0;// Class mapping for YOLOv8
std::map<int, std::string> class_map = {{0, "person"},{1, "bicycle"},{2, "car"},{3, "motorcycle"},{4, "airplane"},{5, "bus"},{6, "train"},{7, "truck"},{8, "boat"},{9, "traffic light"},{10, "fire hydrant"},{11, "stop sign"},{12, "parking meter"},{13, "bench"},{14, "bird"},{15, "cat"},{16, "dog"},{17, "horse"},{18, "sheep"},{19, "cow"},{20, "elephant"},{21, "bear"},{22, "zebra"},{23, "giraffe"},{24, "backpack"},{25, "umbrella"},{26, "handbag"},{27, "tie"},{28, "suitcase"},{29, "frisbee"},{30, "skis"},{31, "snowboard"},{32, "sports ball"},{33, "kite"},{34, "baseball bat"},{35, "baseball glove"},{36, "skateboard"},{37, "surfboard"},{38, "tennis racket"},{39, "bottle"},{40, "wine glass"},{41, "cup"},{42, "fork"},{43, "knife"},{44, "spoon"},{45, "bowl"},{46, "banana"},{47, "apple"},{48, "sandwich"},{49, "orange"},{50, "broccoli"},{51, "carrot"},{52, "hot dog"},{53, "pizza"},{54, "donut"},{55, "cake"},{56, "chair"},{57, "couch"},{58, "potted plant"},{59, "bed"},{60, "dining table"},{61, "toilet"},{62, "tv"},{63, "laptop"},{64, "mouse"},{65, "remote"},{66, "keyboard"},{67, "cell phone"},{68, "microwave"},{69, "oven"},{70, "toaster"},{71, "sink"},{72, "refrigerator"},{73, "book"},{74, "clock"},{75, "vase"},{76, "scissors"},{77, "teddy bear"},{78, "hair drier"},{79, "toothbrush"}};struct Detection {float x1, y1, x2, y2;float score;int class_id;};float calculateIoU(const Detection& box1, const Detection& box2) {float inter_x1 = std::max(box1.x1, box2.x1);float inter_y1 = std::max(box1.y1, box2.y1);float inter_x2 = std::min(box1.x2, box2.x2);float inter_y2 = std::min(box1.y2, box2.y2);float inter_area = std::max(0.0f, inter_x2 - inter_x1) * std::max(0.0f, inter_y2 - inter_y1);float box1_area = (box1.x2 - box1.x1) * (box1.y2 - box1.y1);float box2_area = (box2.x2 - box2.x1) * (box2.y2 - box2.y1);return inter_area / (box1_area + box2_area - inter_area);}
std::vector<Detection> nonMaximumSuppression(const std::vector<Detection>& detections,float score_threshold = 0.45,float iou_threshold = 0.7) {
std::vector<Detection> filtered_detections;
std::vector<Detection> candidates;// Filter by score thresholdfor (const auto& det : detections) {if (det.score >= score_threshold) {
candidates.push_back(det);}}// Sort by score in descending order
std::sort(candidates.begin(), candidates.end(),[](const Detection& a, const Detection& b) { return a.score > b.score; });// NMSwhile (!candidates.empty()) {// Take the highest scoring detection
Detection best_det = candidates[0];
filtered_detections.push_back(best_det);
candidates.erase(candidates.begin());// Remove overlapping detectionsfor (auto it = candidates.begin(); it != candidates.end();) {if (calculateIoU(best_det, *it) > iou_threshold) {
it = candidates.erase(it);} else {++it;}}}return filtered_detections;}void drawBoxOnImage(cv::Mat& image, const Detection& det,float scale_x = 1.0f, float scale_y = 1.0f) {// Scale coordinates back to original image sizeint x1 = static_cast<int>(det.x1 * scale_x);int y1 = static_cast<int>(det.y1 * scale_y);int x2 = static_cast<int>(det.x2 * scale_x);int y2 = static_cast<int>(det.y2 * scale_y);// Clamp coordinates to image boundaries
x1 = std::max(0, std::min(image.cols - 1, x1));
y1 = std::max(0, std::min(image.rows - 1, y1));
x2 = std::max(0, std::min(image.cols - 1, x2));
y2 = std::max(0, std::min(image.rows - 1, y2));if (x1 >= x2 || y1 >= y2) return; // Skip invalid boxes// Draw rectangle (BGR color: green)
cv::rectangle(image, cv::Point(x1, y1), cv::Point(x2, y2), cv::Scalar(0, 255, 0), 2);// Create label text
std::string label = class_map[det.class_id] + " " + std::to_string(det.score).substr(0, 4);// Draw label backgroundint baseline = 0;
cv::Size text_size = cv::getTextSize(label, cv::FONT_HERSHEY_SIMPLEX, 0.5, 2, &baseline);
cv::rectangle(image, cv::Point(x1, y1 - text_size.height - baseline),
cv::Point(x1 + text_size.width, y1), cv::Scalar(0, 255, 0), cv::FILLED);// Draw label text
cv::putText(image, label, cv::Point(x1, y1 - baseline),
cv::FONT_HERSHEY_SIMPLEX, 0.5, cv::Scalar(0, 0, 0), 2);}
class YOLOv8Detector {
private:
LibAppBuilder libAppBuilder;
bool initialized = false;
public:YOLOv8Detector() = default;~YOLOv8Detector() {if (initialized) {
libAppBuilder.ModelDestroy(MODEL_NAME);}}
bool Initialize() {// Get current working directory
fs::path execution_ws = fs::current_path();
fs::path backend_lib_path = execution_ws / "libQnnHtp.so";
fs::path system_lib_path = execution_ws / "libQnnSystem.so";
fs::path model_path = execution_ws / (MODEL_NAME + ".bin");// Disable OpenCV logging
cv::utils::logging::setLogLevel(cv::utils::logging::LOG_LEVEL_ERROR);SetLogLevel(1);SetProfilingLevel(1); // ProfilingLevel::BASIC
std::cout << "Initializing YOLOv8 model..." << std::endl;int ret = libAppBuilder.ModelInitialize(MODEL_NAME, model_path.string(),
backend_lib_path.string(), system_lib_path.string());if (ret < 0) {
std::cout << "Failed to initialize YOLOv8 model" << std::endl;return false;}
initialized = true;
std::cout << "YOLOv8 model initialized successfully" << std::endl;return true;}
std::vector<Detection> Detect(cv::Mat& image) {if (!initialized) return {};
frameCounter++;// Save original dimensions for scalingint orig_height = image.rows;int orig_width = image.cols;float scale_x = static_cast<float>(orig_width) / IMAGE_SIZE;float scale_y = static_cast<float>(orig_height) / IMAGE_SIZE;// Resize image to model input size
cv::Mat resized_image;
cv::resize(image, resized_image, cv::Size(IMAGE_SIZE, IMAGE_SIZE),0, 0, cv::INTER_LINEAR);// Convert BGR to RGB and normalize to [0, 1]
cv::Mat rgb_image;
cv::cvtColor(resized_image, rgb_image, cv::COLOR_BGR2RGB);
cv::Mat float_image;
rgb_image.convertTo(float_image, CV_32FC3, 1.0 / 255.0);// Prepare input tensor (NHWC format)
std::vector<float> input_data(IMAGE_SIZE * IMAGE_SIZE * 3);memcpy(input_data.data(), float_image.data, input_data.size() * sizeof(float));// Set performance profileSetPerfProfileGlobal("burst");// Prepare input/output buffers
std::vector<uint8_t*> inputBuffers;
std::vector<uint8_t*> outputBuffers;
std::vector<size_t> outputSize;
inputBuffers.push_back(reinterpret_cast<uint8_t*>(input_data.data()));// Perform inference
std::string perfProfile = "burst";int ret = libAppBuilder.ModelInference(MODEL_NAME, inputBuffers, outputBuffers,
outputSize, perfProfile);// Release performance profileRelPerfProfileGlobal();if (ret < 0) {
std::cout << "Inference failed" << std::endl;return {};}// Parse output tensorsif (outputBuffers.size() < 3) {
std::cout << "Unexpected number of output buffers: " << outputBuffers.size() << std::endl;return {};}// Get output datafloat* scores_data = reinterpret_cast<float*>(outputBuffers[0]);float* class_ids_data = reinterpret_cast<float*>(outputBuffers[1]);float* boxes_data = reinterpret_cast<float*>(outputBuffers[2]);// Assuming output shape is [1, 8400, ...]const int num_predictions = 8400;// Collect all detections
std::vector<Detection> all_detections;for (int i = 0; i < num_predictions; i++) {
Detection det;
det.score = scores_data[i];
det.class_id = static_cast<int>(class_ids_data[i]);// Box coordinates: [x1, y1, x2, y2]
det.x1 = boxes_data[i * 4];
det.y1 = boxes_data[i * 4 + 1];
det.x2 = boxes_data[i * 4 + 2];
det.y2 = boxes_data[i * 4 + 3];// Scale back to original image coordinates
det.x1 *= scale_x;
det.y1 *= scale_y;
det.x2 *= scale_x;
det.y2 *= scale_y;
all_detections.push_back(det);}// Apply NMS
std::vector<Detection> filtered_detections = nonMaximumSuppression(all_detections);// Free output buffersfor (auto buffer : outputBuffers) {free(buffer);}return filtered_detections;}};
class CameraFrame : public wxFrame
{
public:CameraFrame(const wxString& title);~CameraFrame();
private:
wxMutex m_imageMutex;
wxImage m_frameImage;
GstElement *m_pipeline = nullptr;
GstElement *m_appsink = nullptr;
YOLOv8Detector m_detector;
bool InitGstPipeline();static GstFlowReturn NewSampleCallback(GstAppSink *sink, gpointer user_data);void ConvertGstBufferToWxImage(GstBuffer *buffer, GstCaps *caps);void OnPaint(wxPaintEvent& event);void OnClose(wxCloseEvent& event);DECLARE_EVENT_TABLE()};
class CameraApp : public wxApp
{
public:
virtual bool OnInit();};IMPLEMENT_APP(CameraApp)BEGIN_EVENT_TABLE(CameraFrame, wxFrame)EVT_PAINT(CameraFrame::OnPaint)EVT_CLOSE(CameraFrame::OnClose)END_EVENT_TABLE()
bool CameraApp::OnInit(){gst_init(nullptr, nullptr);
CameraFrame *frame = new CameraFrame(wxT("YOLOv8 Real-time Detection (640x480)"));
frame->Show(true);return true;}
CameraFrame::CameraFrame(const wxString& title): wxFrame(nullptr, wxID_ANY, title, wxDefaultPosition, wxSize(640, 480)){// Initialize detectorif (!m_detector.Initialize()) {wxLogError("Failed to initialize YOLOv8 detector");Close();return;}// Initialize pipeline and startif (InitGstPipeline()) {gst_element_set_state(m_pipeline, GST_STATE_PLAYING);//wxLogMessage("GStreamer pipeline started successfully");} else {wxLogError("Failed to init GStreamer pipeline");Close();}}
CameraFrame::~CameraFrame(){if (m_pipeline) {gst_element_set_state(m_pipeline, GST_STATE_NULL);gst_object_unref(m_pipeline);}gst_deinit();}static void OnBusError(GstBus* bus, GstMessage* msg, gpointer data){
GError* err = nullptr;
gchar* debug_info = nullptr;gst_message_parse_error(msg, &err, &debug_info);wxLogError("GStreamer error: %s", err ? err->message : "Unknown error");g_error_free(err);g_free(debug_info);}
bool CameraFrame::InitGstPipeline(){const gchar *pipelineDesc = "qtiqmmfsrc name=camsrc ! ""video/x-raw,format=NV12,width=640,height=480,framerate=30/1 ! ""videoconvert ! ""video/x-raw,format=BGR ! ""appsink name=appsink sync=false max-buffers=1 drop=true";// Create pipeline
m_pipeline = gst_parse_launch(pipelineDesc, nullptr);if (!m_pipeline) return false;
GstBus* bus = gst_pipeline_get_bus(GST_PIPELINE(m_pipeline));gst_bus_add_signal_watch(bus);g_signal_connect(bus, "message::error", G_CALLBACK(OnBusError), this);gst_object_unref(bus);// Get appsink element
m_appsink = gst_bin_get_by_name(GST_BIN(m_pipeline), "appsink");if (!m_appsink) return false;// Configure appsinkgst_app_sink_set_emit_signals(GST_APP_SINK(m_appsink), TRUE);gst_app_sink_set_drop(GST_APP_SINK(m_appsink), TRUE);gst_app_sink_set_max_buffers(GST_APP_SINK(m_appsink), 1);
GstAppSinkCallbacks callbacks = {nullptr, nullptr, NewSampleCallback, nullptr, nullptr, nullptr};gst_app_sink_set_callbacks(GST_APP_SINK(m_appsink), &callbacks, this, nullptr);return true;}
GstFlowReturn CameraFrame::NewSampleCallback(GstAppSink *sink, gpointer user_data){
CameraFrame *frame = static_cast<CameraFrame*>(user_data);
GstSample *sample = gst_app_sink_pull_sample(sink);if (!sample) return GST_FLOW_ERROR;
GstBuffer *buffer = gst_sample_get_buffer(sample);
GstCaps *caps = gst_sample_get_caps(sample);if (buffer && caps) {
frame->ConvertGstBufferToWxImage(buffer, caps);
frame->Refresh();}gst_sample_unref(sample);return GST_FLOW_OK;}void CameraFrame::ConvertGstBufferToWxImage(GstBuffer *buffer, GstCaps *caps){
GstVideoInfo info;if (!gst_video_info_from_caps(&info, caps)) {wxLogWarning("Failed to get video info from caps");return;}// Validate video dimensionsif (info.width <= 0 || info.height <= 0) {wxLogWarning("Invalid video dimensions: %dx%d", info.width, info.height);return;}
GstMapInfo map;if (!gst_buffer_map(buffer, &map, GST_MAP_READ)) {wxLogWarning("Failed to map GST buffer");return;}// Validate data size (RGB format should be width×height×3)size_t expectedSize = info.width * info.height * 3;if (map.size < expectedSize) {wxLogWarning("Buffer size mismatch: expected %zu, got %zu", expectedSize, map.size);gst_buffer_unmap(buffer, &map);return;}// Convert GST buffer to cv::Mat for detection
cv::Mat frame(info.height, info.width, CV_8UC3, map.data);// Perform detectionauto detections = m_detector.Detect(frame);// Draw detections on framefor (const auto& det : detections) {drawBoxOnImage(frame, det);}// Convert BGR to RGB for wxImage
cv::cvtColor(frame, frame, cv::COLOR_BGR2RGB);
wxMutexLocker locker(m_imageMutex);
m_frameImage = wxImage(info.width, info.height, frame.data, true).Copy();gst_buffer_unmap(buffer, &map);}void CameraFrame::OnPaint(wxPaintEvent& event){
wxPaintDC dc(this);
wxMutexLocker locker(m_imageMutex);if (!m_frameImage.IsOk() || m_frameImage.GetWidth() <= 0 || m_frameImage.GetHeight() <= 0) {// Draw default background
dc.SetBackground(wxBrush(wxColour(50, 50, 50)));
dc.Clear();// Draw status text
dc.SetTextForeground(wxColour(255, 255, 255));
dc.DrawText(wxT("Waiting for camera feed..."), wxPoint(20, 20));return;}// Draw image, scaled to window size
wxSize clientSize = GetClientSize();if (clientSize.GetWidth() <= 0 || clientSize.GetHeight() <= 0)return;
wxBitmap bmp(m_frameImage.Scale(clientSize.GetWidth(), clientSize.GetHeight(), wxIMAGE_QUALITY_BILINEAR));
dc.DrawBitmap(bmp, 0, 0, false);}void CameraFrame::OnClose(wxCloseEvent& event){Destroy();}
创建Makefile¶
创建一个Makefile文件，内容如下：
SRCS += main.cpp
SRCS += $(wildcard ~/ai-engine-direct-helper/src/*.cpp)
SRCS += $(wildcard ~/ai-engine-direct-helper/src/Log/*.cpp)
SRCS += $(wildcard ~/ai-engine-direct-helper/src/PAL/src/linux/*.cpp)
SRCS += $(wildcard ~/ai-engine-direct-helper/src/Utils/*.cpp)
SRCS += $(wildcard ~/ai-engine-direct-helper/src/WrapperUtils/*.cpp)
SRCS += $(wildcard ~/ai-engine-direct-helper/src/PAL/src/common/*.cpp)
OBJS = $(patsubst %cpp, %o, $(SRCS))
DEPS = $(patsubst %cpp, %d, $(SRCS))
CXXFLAGS += -I/usr/include/opencv4
CXXFLAGS += -I/usr/include/wx-3.2
CXXFLAGS += -I ~/qairt/2.37.1.250807/include/QNN
CXXFLAGS += -I ~/ai-engine-direct-helper/src
CXXFLAGS += -I ~/ai-engine-direct-helper/src/Utils
CXXFLAGS += -I ~/ai-engine-direct-helper/src/WrapperUtils
CXXFLAGS += -I ~/ai-engine-direct-helper/src/Log
CXXFLAGS += -I ~/ai-engine-direct-helper/src/PAL/include
CXXFLAGS += -I/usr/include/torch/csrc/api/include
LDFLAGS += -lopencv_core -lopencv_highgui -lopencv_imgcodecs -lopencv_imgproc -lopencv_videoio
CXXFLAGS += `wx-config --cxxflags` `pkg-config --cflags gstreamer-1.0 gstreamer-app-1.0 gstreamer-video-1.0` -Wall -g
LDFLAGS += `wx-config --libs` `pkg-config --libs gstreamer-1.0 gstreamer-app-1.0 gstreamer-video-1.0`
TARGET = wx_yolo8
all: $(TARGET)%.o: %.cpp
g++ -c -g -MMD $(CXXFLAGS) $< -o $@$(TARGET): ${OBJS}
g++ -o $@ $^ ${LDFLAGS}sinclude $(DEPS).PHONY: clean
clean:$(RM) $(TARGET) ${OBJS} ${DEPS}
编译程序¶
执行命令 make 编译程序，获得可执行程序文件wx_yolo8。
获取模型文件¶
QAI AppBuilder 演示YOLOv8-det示例时会下载模型文件至yolov8_det/models/yolov8_det。也可点击 此处 下载模型文件。
获取运行时库文件¶
请从已解压的v2.37.1.250807目录中获取以下运行时库文件。
libQnnHtp.so
libQnnHtpV68Skel.so
libQnnHtpV68Stub.so
libQnnSystem.so
运行程序¶
执行下列命令：
FILE_PATH=$(sudo find /run/user/1001 -type f -name '.mutter-*' | head -n 1)sudo XAUTHORITY="$FILE_PATH" \LD_LIBRARY_PATH=lib:$LD_LIBRARY_PATH \GST_PLUGIN_PATH=/usr/lib/gstreamer-1.0:$GST_PLUGIN_PATH \DISPLAY=:0 ./wx_yolo8
运行效果¶
快速部署验证¶
将编译后的程序和运行需要的文件打包为 yolov8-det-deploy.tar.gz，可以快速部署验证。
tar xvf yolov8-det-deploy.tar.gz
#其中启动摄像头需要root权限，按照提示输入sudo密码即可。cd yolo-deploy
./run.sh