0
0

Delete article

Deleted articles cannot be recovered.

Draft of this article would be also deleted.

Are you sure you want to delete this article?

@tom_tom_tom(トム トムトム)

ネットワークカメラの取得と表示

0
Last updated at Posted at 2026-01-27

はじめに

先日、ネットワークカメラの設定を投稿させていただきました。

今回は設定したネットワークカメラをOpenCVを使用して取得し表示します。

環境

Ubuntu24.04
OpenCV 4.6.0
Qt Creator 13.0.0 Based on Qt6.4.2(GCC 13.2.0,x86_64)

インストール

前提条件

Update済み

OpenCVのインストール

sudo apt install -y libopencv-dev

Qtのインストール

sudo apt install -y build-essential gdb cmake ninja-build pkg-config qt6-base-dev qt6-base-dev-tools qt6-tools-dev qt6-tools-dev-tools qt6-declarative-dev qt6-svg-dev qt6-networkauth-dev libglx-dev libgl1-mesa-dev clang qtcreator

QtCreatorでプロジェクトの作成(ビルドシステムはqmake)

適当でOK(私はnetCamで作成)

追加変更するファイル

追加(後述)

getCamThread.cpp
getCamThread.h

変更(後述)

mainwindow.cpp
mainwindow.h
mainwindow.ui
netCam.pro

追加ファイル詳細

getCamThread.cpp
#include "getCamThread.h"

#define CAMERA_FPS				30
#define CAM_SIZE_WIDTH			1280
#define CAM_SIZE_HEIGHT			720
#define WAIT_TIME				(1000 / CAMERA_FPS)

getCamThread::getCamThread(QObject *parent, bool b) : QThread(parent), Stop(b)
{
}

getCamThread::~getCamThread()
{
	cap_.release();
	Stop = true;
}

bool getCamThread::initCam(QString cameraUrl)
{
	bool ret = true;

	cap_.open(cameraUrl.toStdString());
	if(cap_.isOpened()){
		cap_.set(cv::CAP_PROP_BUFFERSIZE,1);
		cap_.set(cv::CAP_PROP_FRAME_WIDTH, CAM_SIZE_WIDTH);
		cap_.set(cv::CAP_PROP_FRAME_HEIGHT, CAM_SIZE_HEIGHT);
		cap_.set(cv::CAP_PROP_FPS, CAMERA_FPS);
		cap_.set(cv::CAP_PROP_FOURCC, cv::VideoWriter::fourcc('H', '2', '6', '4'));
	} else {
		ret = false;
	}

	return ret;
}

void getCamThread::run(void)
{
	QMutex mutex;
	cv::Mat frame;

	while(cap_.read(frame)){
		// prevent other threads from changing the "Stop" value
		mutex.lock();
		if(this->Stop){
			 break;
		}
		mutex.unlock();

		cv::cvtColor(frame, dst_, cv::COLOR_BGR2RGB);

		// emit the signal for the count label
		emit valueChangedCam(&dst_);

		// slowdown the count change, msec
		this->msleep(WAIT_TIME);
    }
	cap_.release();
}

void getCamThread::threadStop(void)
{
	Stop = true;
}
getCamThread.h
#ifndef GETCAMTHREAD_H
#define GETCAMTHREAD_H

#include <QString>
#include <QThread>
#include <QMutex>
#include <QObject>
#include <opencv2/opencv.hpp>

class getCamThread : public QThread
{
	Q_OBJECT

	public:
		explicit getCamThread(QObject *parent = nullptr, bool b = false);
		~getCamThread();
		bool initCam(QString);
		void run(void);
		void threadStop(void);
	public:
		bool Stop;
	signals:
		void valueChangedCam(cv::Mat*);
	private:
		cv::VideoCapture cap_;
		cv::Mat dst_;
};
#endif // GETCAMTHREAD_H

変更ファイル詳細

mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow)
{
	QMessageBox msgBox(this);
	QString messText;

	ui->setupUi(this);

	getCamT_ = new getCamThread(this);
	if(!getCamT_->initCam("rtsp://admin:123456@192.168.1.168/0")){
		messText = "カメラの初期化に失敗しました。";
		msgBox.setText(messText);					// メッセージ
		msgBox.setWindowTitle(tr("Information"));	// タイトル
		msgBox.setStandardButtons(QMessageBox::Ok);	// ボタン
		msgBox.setDefaultButton(QMessageBox::Ok);	// デフォルトボタン
		msgBox.setIcon(QMessageBox::Information);	// アイコン
		msgBox.exec();								// 表示
		exit(-1);									// プログラム終了
	}
	// signal/slotの接続
	connect(getCamT_, SIGNAL(valueChangedCam(cv::Mat*)), this, SLOT(onValueChangedCam(cv::Mat*)));
	getCamT_->start();
}


MainWindow::~MainWindow()
{
	getCamT_->threadStop();
	delete getCamT_;
	delete ui;
}


void MainWindow::onValueChangedCam(cv::Mat *dst)
{
	// イメージ作成
	qtImage_ = QImage((const unsigned char*)(dst->data), dst->cols, dst->rows, QImage::Format_RGB888);

	// ラベルへ表示
	ui->label->setPixmap(QPixmap::fromImage(qtImage_));
}
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QMessageBox>
#include "getCamThread.h"


QT_BEGIN_NAMESPACE
namespace Ui {
class MainWindow;
}
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
	Q_OBJECT

	public:
		MainWindow(QWidget *parent = nullptr);
		~MainWindow();

	private:
		Ui::MainWindow *ui;
		getCamThread *getCamT_;
		QImage qtImage_;

	public slots:
		void onValueChangedCam(cv::Mat*);

};
#endif // MAINWINDOW_H
mainwindow.ui
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>1300</width>
    <height>760</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QLabel" name="label">
    <property name="geometry">
     <rect>
      <x>10</x>
      <y>20</y>
      <width>1280</width>
      <height>720</height>
     </rect>
    </property>
    <property name="styleSheet">
     <string notr="true">background-color: rgb(255, 255, 255);</string>
    </property>
    <property name="text">
     <string/>
    </property>
   </widget>
  </widget>
 </widget>
 <resources/>
 <connections/>
</ui>
netcam.pro
QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
	getCamThread.cpp \
	main.cpp \
	mainwindow.cpp

HEADERS += \
	getCamThread.h \
	mainwindow.h

FORMS += \
	mainwindow.ui

TRANSLATIONS += \
	netCam_ja_JP.ts
#CONFIG += lrelease
#CONFIG += embed_translations

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target


INCLUDEPATH += /usr/include/opencv4
DEPENDPATH += /usr/include/opencv4

unix:!macx: LIBS += \
-lopencv_alphamat \
-lopencv_aruco \
-lopencv_barcode \
-lopencv_bgsegm \
-lopencv_bioinspired \
-lopencv_calib3d \
-lopencv_ccalib \
-lopencv_core \
-lopencv_cvv \
-lopencv_datasets \
-lopencv_dnn \
-lopencv_dnn_objdetect \
-lopencv_dnn_superres \
-lopencv_dpm \
-lopencv_face \
-lopencv_features2d \
-lopencv_flann \
-lopencv_freetype \
-lopencv_fuzzy \
-lopencv_hdf \
-lopencv_hfs \
-lopencv_highgui \
-lopencv_img_hash \
-lopencv_imgcodecs \
-lopencv_imgproc \
-lopencv_intensity_transform \
-lopencv_line_descriptor \
-lopencv_mcc \
-lopencv_ml \
-lopencv_objdetect \
-lopencv_optflow \
-lopencv_phase_unwrapping \
-lopencv_photo \
-lopencv_plot \
-lopencv_quality \
-lopencv_rapid \
-lopencv_reg \
-lopencv_rgbd \
-lopencv_saliency \
-lopencv_shape \
-lopencv_stereo \
-lopencv_stitching \
-lopencv_structured_light \
-lopencv_superres \
-lopencv_surface_matching \
-lopencv_text \
-lopencv_tracking \
-lopencv_video \
-lopencv_videoio \
-lopencv_videostab \
-lopencv_viz \
-lopencv_wechat_qrcode \
-lopencv_ximgproc \
-lopencv_xobjdetect \
-lopencv_xphoto

実行

Qt Creatorの▶をクリックすると実行できます。
mainwindo.cppの19行目の

if(!getCamT_->initCam("rtsp://admin:123456@192.168.1.168/0")){

は各自のIPアドレスにしてください
サブストリームを表示させたいときは、

if(!getCamT_->initCam("rtsp://admin:123456@192.168.1.168/1")){

にしてください。

実行画面

Screenshot.jpg
映像はモザイク処理をしています。

前に投降した

に近いです。

0
0
0

Register as a new user and use Qiita more conveniently

  1. You get articles that match your needs
  2. You can efficiently read back useful information
  3. You can use dark theme
What you can do with signing up
Sign upLogin
0
0

Delete article

Deleted articles cannot be recovered.

Draft of this article would be also deleted.

Are you sure you want to delete this article?