Adding FOURCC usb camera support (#1366)

* Adding FOURCC usb camera support

* Improved warnings

* more checks and warnings

corelib/include/rtabmap/core/camera/CameraStereoVideo.h

@@ -69,6 +69,7 @@ public:
 	virtual std::string getSerial() const;
 
 	void setResolution(int width, int height) {_width=width, _height=height;}
+	void setFOURCC(const std::string & fourcc) { _fourcc = fourcc; }
 
 protected:
 	virtual SensorData captureImage(SensorCaptureInfo * info = 0);
@@ -86,6 +87,7 @@ private:
 	int usbDevice2_;
 	int _width;
 	int _height;
+	std::string _fourcc;
 };
 
 } // namespace rtabmap

corelib/include/rtabmap/core/camera/CameraVideo.h

@@ -62,6 +62,7 @@ public:
 	 * has been loaded, thus resolution from calibration is used.
 	 * */
 	void setResolution(int width, int height) {_width=width, _height=height;}
+	void setFOURCC(const std::string & fourcc) { _fourcc = fourcc; }
 
 protected:
 	virtual SensorData captureImage(SensorCaptureInfo * info = 0);
@@ -79,6 +80,7 @@ private:
 	std::string _guid;
 	int _width;
 	int _height;
+	std::string _fourcc;
 
 	CameraModel _model;
 };

corelib/src/camera/CameraStereoVideo.cpp

@@ -199,14 +199,39 @@ bool CameraStereoVideo::init(const std::string & calibrationFolder, const std::s
 	{
 		if(stereoModel_.isValidForProjection())
 		{
+			if(_width > 0 && _height > 0 && (_width!=stereoModel_.left().imageWidth() || _height != stereoModel_.left().imageHeight()))
+			{
+				UWARN("Desired resolution of %dx%d is set but calibration has "
+				      "been loaded with resolution %dx%d, using calibration resolution.",
+					  _width, _height,
+					  stereoModel_.left().imageWidth(), stereoModel_.left().imageHeight());
+			}
+
 			if(capture_.isOpened())
 			{
-				capture_.set(CV_CAP_PROP_FRAME_WIDTH, stereoModel_.left().imageWidth()*(capture2_.isOpened()?1:2));
+				bool resolutionSet = false;
-				capture_.set(CV_CAP_PROP_FRAME_HEIGHT, stereoModel_.left().imageHeight());
+				resolutionSet = capture_.set(CV_CAP_PROP_FRAME_WIDTH, stereoModel_.left().imageWidth()*(capture2_.isOpened()?1:2));
+				resolutionSet = resolutionSet && capture_.set(CV_CAP_PROP_FRAME_HEIGHT, stereoModel_.left().imageHeight());
 				if(capture2_.isOpened())
 				{
-					capture2_.set(CV_CAP_PROP_FRAME_WIDTH, stereoModel_.right().imageWidth());
+					resolutionSet = resolutionSet && capture2_.set(CV_CAP_PROP_FRAME_WIDTH, stereoModel_.right().imageWidth());
-					capture2_.set(CV_CAP_PROP_FRAME_HEIGHT, stereoModel_.right().imageHeight());
+					resolutionSet = resolutionSet && capture2_.set(CV_CAP_PROP_FRAME_HEIGHT, stereoModel_.right().imageHeight());
+				}
+
+				// Check if the resolution was set successfully
+				int actualWidth = int(capture_.get(CV_CAP_PROP_FRAME_WIDTH));
+				int actualHeight = int(capture_.get(CV_CAP_PROP_FRAME_HEIGHT));
+				if(!resolutionSet ||
+				   actualWidth != stereoModel_.left().imageWidth()*(capture2_.isOpened()?1:2) ||
+				   actualHeight != stereoModel_.left().imageHeight())
+				{
+					UERROR("Calibration resolution (%dx%d) cannot be set to camera driver, "
+					      "actual resolution is %dx%d. You would have to re-calibrate with one "
+						  "supported format by your camera. "
+						  "Do \"v4l2-ctl --list-formats-ext\" to list all supported "
+						  "formats by your camera. For side-by-side format, you should set listed width/2.",
+						  stereoModel_.left().imageWidth(), stereoModel_.left().imageHeight(),
+						  actualWidth/(capture2_.isOpened()?1:2), actualHeight);
 				}
 			}
 		}
@@ -214,13 +239,92 @@ bool CameraStereoVideo::init(const std::string & calibrationFolder, const std::s
 		{
 			if(capture_.isOpened())
 			{
-				capture_.set(CV_CAP_PROP_FRAME_WIDTH, _width*(capture2_.isOpened()?1:2));
+				bool resolutionSet = false;
-				capture_.set(CV_CAP_PROP_FRAME_HEIGHT, _height);
+				resolutionSet = capture_.set(CV_CAP_PROP_FRAME_WIDTH, _width*(capture2_.isOpened()?1:2));
+				resolutionSet = resolutionSet && capture_.set(CV_CAP_PROP_FRAME_HEIGHT, _height);
 				if(capture2_.isOpened())
 				{
-					capture2_.set(CV_CAP_PROP_FRAME_WIDTH, _width);
+					resolutionSet = resolutionSet && capture2_.set(CV_CAP_PROP_FRAME_WIDTH, _width);
-					capture2_.set(CV_CAP_PROP_FRAME_HEIGHT, _height);
+					resolutionSet = resolutionSet && capture2_.set(CV_CAP_PROP_FRAME_HEIGHT, _height);
 				}
+
+				// Check if the resolution was set successfully
+				int actualWidth = int(capture_.get(CV_CAP_PROP_FRAME_WIDTH));
+				int actualHeight = int(capture_.get(CV_CAP_PROP_FRAME_HEIGHT));
+				if(!resolutionSet ||
+				   actualWidth != _width*(capture2_.isOpened()?1:2) ||
+				   actualHeight != _height)
+				{
+					UWARN("Desired resolution (%dx%d) cannot be set to camera driver, "
+					      "actual resolution is %dx%d. "
+						  "Do \"v4l2-ctl --list-formats-ext\" to list all supported "
+						  "formats by your camera. For side-by-side format, you should set listed width/2.",
+						  _width, _height,
+						  actualWidth/(capture2_.isOpened()?1:2), actualHeight);
+				}
+			}
+		}
+
+		// Set FPS
+		if (this->getFrameRate() > 0)
+		{
+			bool fpsSupported = false;
+			fpsSupported = capture_.set(CV_CAP_PROP_FPS, this->getFrameRate());
+			if (capture2_.isOpened())
+			{
+				fpsSupported = fpsSupported && capture2_.set(CV_CAP_PROP_FPS, this->getFrameRate());
+			}
+			if(fpsSupported)
+			{
+				// Check if the FPS was set successfully
+				double actualFPS = capture_.get(cv::CAP_PROP_FPS);
+				
+				if(fabs(actualFPS - this->getFrameRate()) < 0.01)
+				{
+					this->setFrameRate(0);
+				}
+				else
+				{
+					UWARN("Desired FPS (%f Hz) cannot be set to camera driver, "
+					      "actual FPS is %f Hz. We will throttle to lowest FPS. "
+						  "Do \"v4l2-ctl --list-formats-ext\" to list all supported "
+						  "formats by your camera.",
+						  this->getFrameRate(), actualFPS);
+					if(this->getFrameRate() > actualFPS)
+					{
+						this->setFrameRate(0);
+					}
+				}
+			}
+		}
+
+		// Set FOURCC
+		if (!_fourcc.empty())
+		{
+			if(_fourcc.size() == 4)
+			{
+				std::string fourccUpperCase = uToUpperCase(_fourcc);
+				int fourcc = cv::VideoWriter::fourcc(fourccUpperCase.at(0), fourccUpperCase.at(1), fourccUpperCase.at(2), fourccUpperCase.at(3));
+				bool fourccSupported = false;
+				fourccSupported = capture_.set(CV_CAP_PROP_FOURCC, fourcc);
+				if (capture2_.isOpened())
+				{
+					fourccSupported = fourccSupported && capture2_.set(CV_CAP_PROP_FOURCC, fourcc);
+				}
+
+				// Check if the FOURCC was set successfully
+				int actualFourcc = int(capture_.get(CV_CAP_PROP_FOURCC));
+
+				if(!fourccSupported || actualFourcc != fourcc)
+				{
+					UWARN("Camera doesn't support provided FOURCC \"%s\". "
+						  "Do \"v4l2-ctl --list-formats-ext\" to list all supported "
+						  "formats by your camera.", fourccUpperCase.c_str());
+				}
+			}
+			else
+			{
+				UERROR("FOURCC parameter should be 4 characters, current value is \"%s\"", _fourcc.c_str());
 			}
 		}
 	}

corelib/src/camera/CameraVideo.cpp

@@ -134,13 +134,101 @@ bool CameraVideo::init(const std::string & calibrationFolder, const std::string
 		{
 			if(_model.isValidForProjection())
 			{
-				_capture.set(CV_CAP_PROP_FRAME_WIDTH, _model.imageWidth());
+				if(_width > 0 && _height > 0 && (_width!=_model.imageWidth() || _height != _model.imageHeight()))
-				_capture.set(CV_CAP_PROP_FRAME_HEIGHT, _model.imageHeight());
+				{
+					UWARN("Desired resolution of %dx%d is set but calibration has "
+						"been loaded with resolution %dx%d, using calibration resolution.",
+						_width, _height,
+						_model.imageWidth(), _model.imageHeight());
+				}
+
+				bool resolutionSet = false;
+				resolutionSet = _capture.set(CV_CAP_PROP_FRAME_WIDTH, _model.imageWidth());
+				resolutionSet = resolutionSet && _capture.set(CV_CAP_PROP_FRAME_HEIGHT, _model.imageHeight());
+
+				// Check if the resolution was set successfully
+				int actualWidth = int(_capture.get(CV_CAP_PROP_FRAME_WIDTH));
+				int actualHeight = int(_capture.get(CV_CAP_PROP_FRAME_HEIGHT));
+				if(!resolutionSet ||
+				   actualWidth != _model.imageWidth() ||
+				   actualHeight != _model.imageHeight())
+				{
+					UERROR("Calibration resolution (%dx%d) cannot be set to camera driver, "
+					      "actual resolution is %dx%d. You would have to re-calibrate with one "
+						  "supported format by your camera. "
+						  "Do \"v4l2-ctl --list-formats-ext\" to list all supported "
+						  "formats by your camera.",
+						  _model.imageWidth(), _model.imageHeight(),
+						  actualWidth, actualHeight);
+				}
 			}
 			else if(_width > 0 && _height > 0)
 			{
-				_capture.set(CV_CAP_PROP_FRAME_WIDTH, _width);
+				int resolutionSet = false;
-				_capture.set(CV_CAP_PROP_FRAME_HEIGHT, _height);
+				resolutionSet = _capture.set(CV_CAP_PROP_FRAME_WIDTH, _width);
+				resolutionSet = resolutionSet && _capture.set(CV_CAP_PROP_FRAME_HEIGHT, _height);
+
+				// Check if the resolution was set successfully
+				int actualWidth = int(_capture.get(CV_CAP_PROP_FRAME_WIDTH));
+				int actualHeight = int(_capture.get(CV_CAP_PROP_FRAME_HEIGHT));
+				if(!resolutionSet || actualWidth != _width || actualHeight != _height)
+				{
+					UWARN("Desired resolution (%dx%d) cannot be set to camera driver, "
+					      "actual resolution is %dx%d. "
+						  "Do \"v4l2-ctl --list-formats-ext\" to list all supported "
+						  "formats by your camera.",
+						  _width, _height, actualWidth, actualHeight);
+				}
+			}
+
+			// Set FPS
+			if (this->getFrameRate() > 0 && _capture.set(CV_CAP_PROP_FPS, this->getFrameRate()))
+			{
+				// Check if the FPS was set successfully
+				double actualFPS = _capture.get(cv::CAP_PROP_FPS);
+				
+				if(fabs(actualFPS - this->getFrameRate()) < 0.01)
+				{
+					this->setFrameRate(0);
+				}
+				else
+				{
+					UWARN("Desired FPS (%f Hz) cannot be set to camera driver, "
+						"actual FPS is %f Hz. We will throttle to lowest FPS. "
+						"Do \"v4l2-ctl --list-formats-ext\" to list all supported "
+						"formats by your camera.",
+						this->getFrameRate(), actualFPS);
+					if(this->getFrameRate() > actualFPS)
+					{
+						this->setFrameRate(0);
+					}
+				}
+			}
+
+			// Set FOURCC
+			if (!_fourcc.empty())
+			{
+				if(_fourcc.size() == 4)
+				{
+					std::string fourccUpperCase = uToUpperCase(_fourcc);
+					int fourcc = cv::VideoWriter::fourcc(fourccUpperCase.at(0), fourccUpperCase.at(1), fourccUpperCase.at(2), fourccUpperCase.at(3));
+					
+					bool fourccSupported = _capture.set(CV_CAP_PROP_FOURCC, fourcc);
+
+					// Check if the FOURCC was set successfully
+					int actualFourcc = int(_capture.get(CV_CAP_PROP_FOURCC));
+
+					if(!fourccSupported || actualFourcc != fourcc)
+					{
+						UWARN("Camera doesn't support provided FOURCC \"%s\". "
+							"Do \"v4l2-ctl --list-formats-ext\" to list all supported "
+							"formats by your camera.", fourccUpperCase.c_str());
+					}
+				}
+				else
+				{
+					UERROR("FOURCC parameter should be 4 characters, current value is \"%s\"", _fourcc.c_str());
+				}
 			}
 		}
 		if(_rectifyImages && !_model.isValidForRectification())

guilib/src/PreferencesDialog.cpp

@@ -724,6 +724,7 @@ PreferencesDialog::PreferencesDialog(QWidget * parent) :
 	// usb group
 	connect(_ui->spinBox_usbcam_streamWidth, SIGNAL(valueChanged(int)), this, SLOT(makeObsoleteSourcePanel()));
 	connect(_ui->spinBox_usbcam_streamHeight, SIGNAL(valueChanged(int)), this, SLOT(makeObsoleteSourcePanel()));
+	connect(_ui->lineEdit_usbcam_fourcc, SIGNAL(textChanged(const QString &)), this, SLOT(makeObsoleteSourcePanel()));
 	//video group
 	connect(_ui->source_video_toolButton_selectSource, SIGNAL(clicked()), this, SLOT(selectSourceVideoPath()));
 	connect(_ui->source_video_lineEdit_path, SIGNAL(textChanged(const QString &)), this, SLOT(makeObsoleteSourcePanel()));
@@ -836,6 +837,7 @@ PreferencesDialog::PreferencesDialog(QWidget * parent) :
 	connect(_ui->spinBox_stereo_right_device, SIGNAL(valueChanged(int)), this, SLOT(makeObsoleteSourcePanel()));
 	connect(_ui->spinBox_stereousbcam_streamWidth, SIGNAL(valueChanged(int)), this, SLOT(makeObsoleteSourcePanel()));
 	connect(_ui->spinBox_stereousbcam_streamHeight, SIGNAL(valueChanged(int)), this, SLOT(makeObsoleteSourcePanel()));
+	connect(_ui->lineEdit_stereousbcam_fourcc, SIGNAL(textChanged(const QString &)), this, SLOT(makeObsoleteSourcePanel()));
 
 	connect(_ui->comboBox_stereoZed_resolution, SIGNAL(currentIndexChanged(int)), this, SLOT(makeObsoleteSourcePanel()));
 	connect(_ui->comboBox_stereoZed_quality, SIGNAL(currentIndexChanged(int)), this, SLOT(makeObsoleteSourcePanel()));
@@ -2732,6 +2734,7 @@ void PreferencesDialog::readCameraSettings(const QString & filePath)
 	_ui->spinBox_stereo_right_device->setValue(settings.value("device2", _ui->spinBox_stereo_right_device->value()).toInt());
 	_ui->spinBox_stereousbcam_streamWidth->setValue(settings.value("width", _ui->spinBox_stereousbcam_streamWidth->value()).toInt());
 	_ui->spinBox_stereousbcam_streamHeight->setValue(settings.value("height", _ui->spinBox_stereousbcam_streamHeight->value()).toInt());
+	_ui->lineEdit_stereousbcam_fourcc->setText(settings.value("fourcc", _ui->lineEdit_stereousbcam_fourcc->text()).toString());
 	settings.endGroup(); // StereoVideo
 
 	settings.beginGroup("StereoZed");
@@ -2809,6 +2812,7 @@ void PreferencesDialog::readCameraSettings(const QString & filePath)
 	settings.beginGroup("UsbCam");
 	_ui->spinBox_usbcam_streamWidth->setValue(settings.value("width", _ui->spinBox_usbcam_streamWidth->value()).toInt());
 	_ui->spinBox_usbcam_streamHeight->setValue(settings.value("height", _ui->spinBox_usbcam_streamHeight->value()).toInt());
+	_ui->lineEdit_usbcam_fourcc->setText(settings.value("fourcc", _ui->lineEdit_usbcam_fourcc->text()).toString());
 	settings.endGroup(); // UsbCam
 
 	settings.beginGroup("Video");
@@ -3332,6 +3336,7 @@ void PreferencesDialog::writeCameraSettings(const QString & filePath) const
 	settings.setValue("device2",		_ui->spinBox_stereo_right_device->value());
 	settings.setValue("width",		    _ui->spinBox_stereousbcam_streamWidth->value());
 	settings.setValue("height",		    _ui->spinBox_stereousbcam_streamHeight->value());
+	settings.setValue("fourcc",         _ui->lineEdit_stereousbcam_fourcc->text());
 	settings.endGroup(); // StereoVideo
 
 	settings.beginGroup("StereoZed");
@@ -3407,6 +3412,7 @@ void PreferencesDialog::writeCameraSettings(const QString & filePath) const
 	settings.beginGroup("UsbCam");
 	settings.setValue("width",          _ui->spinBox_usbcam_streamWidth->value());
 	settings.setValue("height",         _ui->spinBox_usbcam_streamHeight->value());
+	settings.setValue("fourcc",         _ui->lineEdit_usbcam_fourcc->text());
 	settings.endGroup(); // UsbCam
 
 	settings.beginGroup("Video");
@@ -6738,6 +6744,10 @@ Camera * PreferencesDialog::createCamera(
 				this->getSourceLocalTransform());
 		}
 		((CameraStereoVideo*)camera)->setResolution(_ui->spinBox_stereousbcam_streamWidth->value(), _ui->spinBox_stereousbcam_streamHeight->value());
+		if(!_ui->lineEdit_stereousbcam_fourcc->text().isEmpty())
+		{
+			((CameraStereoVideo*)camera)->setFOURCC(_ui->lineEdit_stereousbcam_fourcc->text().toStdString());
+		}
 	}
 	else if(driver == kSrcStereoVideo)
 	{
@@ -6866,6 +6876,10 @@ Camera * PreferencesDialog::createCamera(
 			this->getGeneralInputRate(),
 			this->getSourceLocalTransform());
 		((CameraVideo*)camera)->setResolution(_ui->spinBox_usbcam_streamWidth->value(), _ui->spinBox_usbcam_streamHeight->value());
+		if(!_ui->lineEdit_usbcam_fourcc->text().isEmpty())
+		{
+			((CameraVideo*)camera)->setFOURCC(_ui->lineEdit_usbcam_fourcc->text().toStdString());
+		}
 	}
 	else if(driver == kSrcVideo)
 	{

guilib/src/ui/preferencesDialog.ui

@@ -63,7 +63,7 @@
           <property name="geometry">
            <rect>
             <x>0</x>
-            <y>0</y>
+            <y>-269</y>
             <width>713</width>
             <height>4653</height>
            </rect>
@@ -95,7 +95,7 @@
                 <enum>QFrame::Raised</enum>
                </property>
                <property name="currentIndex">
-                <number>24</number>
+                <number>5</number>
                </property>
                <widget class="QWidget" name="page_22">
                 <layout class="QVBoxLayout" name="verticalLayout_29" stretch="0,0">
@@ -3424,7 +3424,7 @@ when using the file type, logs are saved in LogRtabmap.txt (located in the worki
                        <item>
                         <widget class="QStackedWidget" name="stackedWidget_src">
                          <property name="currentIndex">
-                          <number>0</number>
+                          <number>2</number>
                          </property>
                          <widget class="QWidget" name="page_41">
                           <layout class="QVBoxLayout" name="verticalLayout_64">
@@ -5112,7 +5112,7 @@ when using the file type, logs are saved in LogRtabmap.txt (located in the worki
                               <item>
                                <widget class="QStackedWidget" name="stackedWidget_stereo">
                                 <property name="currentIndex">
-                                 <number>4</number>
+                                 <number>5</number>
                                 </property>
                                 <widget class="QWidget" name="page_49">
                                  <layout class="QVBoxLayout" name="verticalLayout_91"/>
@@ -5595,29 +5595,6 @@ when using the file type, logs are saved in LogRtabmap.txt (located in the worki
                                      <string>Usb Camera</string>
                                     </property>
                                     <layout class="QGridLayout" name="gridLayout_99" columnstretch="0,1">
-                                     <item row="0" column="1">
-                                      <widget class="QLabel" name="label_470">
-                                       <property name="text">
-                                        <string>Optional right device ID. It should be -1 if the stereo camera streams side-by-side images.</string>
-                                       </property>
-                                       <property name="wordWrap">
-                                        <bool>true</bool>
-                                       </property>
-                                       <property name="textInteractionFlags">
-                                        <set>Qt::LinksAccessibleByMouse|Qt::TextSelectableByMouse</set>
-                                       </property>
-                                      </widget>
-                                     </item>
-                                     <item row="3" column="0">
-                                      <widget class="QSpinBox" name="spinBox_stereousbcam_streamHeight">
-                                       <property name="minimum">
-                                        <number>0</number>
-                                       </property>
-                                       <property name="maximum">
-                                        <number>10000</number>
-                                       </property>
-                                      </widget>
-                                     </item>
                                      <item row="1" column="1">
                                       <widget class="QLabel" name="label_620">
                                        <property name="text">
@@ -5631,6 +5608,29 @@ when using the file type, logs are saved in LogRtabmap.txt (located in the worki
                                        </property>
                                       </widget>
                                      </item>
+                                     <item row="5" column="0">
+                                      <spacer name="verticalSpacer_51">
+                                       <property name="orientation">
+                                        <enum>Qt::Vertical</enum>
+                                       </property>
+                                       <property name="sizeHint" stdset="0">
+                                        <size>
+                                         <width>20</width>
+                                         <height>0</height>
+                                        </size>
+                                       </property>
+                                      </spacer>
+                                     </item>
+                                     <item row="3" column="0">
+                                      <widget class="QSpinBox" name="spinBox_stereousbcam_streamHeight">
+                                       <property name="minimum">
+                                        <number>0</number>
+                                       </property>
+                                       <property name="maximum">
+                                        <number>10000</number>
+                                       </property>
+                                      </widget>
+                                     </item>
                                      <item row="3" column="1">
                                       <widget class="QLabel" name="label_619">
                                        <property name="text">
@@ -5644,13 +5644,6 @@ when using the file type, logs are saved in LogRtabmap.txt (located in the worki
                                        </property>
                                       </widget>
                                      </item>
-                                     <item row="0" column="0">
-                                      <widget class="QSpinBox" name="spinBox_stereo_right_device">
-                                       <property name="minimum">
-                                        <number>-1</number>
-                                       </property>
-                                      </widget>
-                                     </item>
                                      <item row="1" column="0">
                                       <widget class="QSpinBox" name="spinBox_stereousbcam_streamWidth">
                                        <property name="minimum">
@@ -5661,18 +5654,45 @@ when using the file type, logs are saved in LogRtabmap.txt (located in the worki
                                        </property>
                                       </widget>
                                      </item>
+                                     <item row="0" column="0">
+                                      <widget class="QSpinBox" name="spinBox_stereo_right_device">
+                                       <property name="minimum">
+                                        <number>-1</number>
+                                       </property>
+                                      </widget>
+                                     </item>
+                                     <item row="0" column="1">
+                                      <widget class="QLabel" name="label_470">
+                                       <property name="text">
+                                        <string>Optional right device ID. It should be -1 if the stereo camera streams side-by-side images.</string>
+                                       </property>
+                                       <property name="wordWrap">
+                                        <bool>true</bool>
+                                       </property>
+                                       <property name="textInteractionFlags">
+                                        <set>Qt::LinksAccessibleByMouse|Qt::TextSelectableByMouse</set>
+                                       </property>
+                                      </widget>
+                                     </item>
+                                     <item row="4" column="1">
+                                      <widget class="QLabel" name="label_755">
+                                       <property name="text">
+                                        <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;FOURCC (&lt;a href=&quot;https://fourcc.org/codecs.php&quot;&gt;&lt;span style=&quot; text-decoration: underline; color:#0000ff;&quot;&gt;https://fourcc.org/codecs.php&lt;/span&gt;&lt;/a&gt;).&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+                                       </property>
+                                       <property name="wordWrap">
+                                        <bool>true</bool>
+                                       </property>
+                                       <property name="textInteractionFlags">
+                                        <set>Qt::LinksAccessibleByMouse|Qt::TextSelectableByMouse</set>
+                                       </property>
+                                      </widget>
+                                     </item>
                                      <item row="4" column="0">
-                                      <spacer name="verticalSpacer_51">
+                                      <widget class="QLineEdit" name="lineEdit_stereousbcam_fourcc">
-                                       <property name="orientation">
+                                       <property name="toolTip">
-                                        <enum>Qt::Vertical</enum>
+                                        <string>Should be 4 characters</string>
                                        </property>
-                                       <property name="sizeHint" stdset="0">
+                                      </widget>
-                                        <size>
-                                         <width>20</width>
-                                         <height>0</height>
-                                        </size>
-                                       </property>
-                                      </spacer>
                                      </item>
                                     </layout>
                                    </widget>
@@ -6527,6 +6547,29 @@ when using the file type, logs are saved in LogRtabmap.txt (located in the worki
                                      <string>USB Camera</string>
                                     </property>
                                     <layout class="QGridLayout" name="gridLayout_112" columnstretch="0,1">
+                                     <item row="0" column="0">
+                                      <widget class="QSpinBox" name="spinBox_usbcam_streamWidth">
+                                       <property name="minimum">
+                                        <number>0</number>
+                                       </property>
+                                       <property name="maximum">
+                                        <number>10000</number>
+                                       </property>
+                                      </widget>
+                                     </item>
+                                     <item row="0" column="1">
+                                      <widget class="QLabel" name="label_552">
+                                       <property name="text">
+                                        <string>Stream width (0 for default resolution).</string>
+                                       </property>
+                                       <property name="wordWrap">
+                                        <bool>true</bool>
+                                       </property>
+                                       <property name="textInteractionFlags">
+                                        <set>Qt::LinksAccessibleByMouse|Qt::TextSelectableByMouse</set>
+                                       </property>
+                                      </widget>
+                                     </item>
                                      <item row="1" column="0">
                                       <widget class="QSpinBox" name="spinBox_usbcam_streamHeight">
                                        <property name="minimum">
@@ -6550,10 +6593,17 @@ when using the file type, logs are saved in LogRtabmap.txt (located in the worki
                                        </property>
                                       </widget>
                                      </item>
-                                     <item row="0" column="1">
+                                     <item row="2" column="0">
-                                      <widget class="QLabel" name="label_552">
+                                      <widget class="QLineEdit" name="lineEdit_usbcam_fourcc">
+                                       <property name="toolTip">
+                                        <string>Should be 4 characters</string>
+                                       </property>
+                                      </widget>
+                                     </item>
+                                     <item row="2" column="1">
+                                      <widget class="QLabel" name="label_758">
                                        <property name="text">
-                                        <string>Stream width (0 for default resolution).</string>
+                                        <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;FOURCC (&lt;a href=&quot;https://fourcc.org/codecs.php&quot;&gt;&lt;span style=&quot; text-decoration: underline; color:#0000ff;&quot;&gt;https://fourcc.org/codecs.php&lt;/span&gt;&lt;/a&gt;).&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
                                        </property>
                                        <property name="wordWrap">
                                         <bool>true</bool>
@@ -6563,16 +6613,6 @@ when using the file type, logs are saved in LogRtabmap.txt (located in the worki
                                        </property>
                                       </widget>
                                      </item>
-                                     <item row="0" column="0">
-                                      <widget class="QSpinBox" name="spinBox_usbcam_streamWidth">
-                                       <property name="minimum">
-                                        <number>0</number>
-                                       </property>
-                                       <property name="maximum">
-                                        <number>10000</number>
-                                       </property>
-                                      </widget>
-                                     </item>
                                     </layout>
                                    </widget>
                                   </item>