A camera problem.

[jenya7]

I want to work with a camera on my board.
I include in a pro file

QT += multimedia multimediawidgets

But when I include

#include <QMediaService>
#include <QMediaRecorder>
#include <QCameraViewfinder>
#include <QCameraInfo>
#include <QMediaMetaData>

I get - file not found on all these files.
It happens on Linux installation, on Windows it's OK.

Should I install additional libraries on Linux?

[JonB]

@jenya7 How did you do the Linux installation, did you include the multimedia libraries?

[jenya7]

@JonB said in A camera problem.:

@jenya7 How did you do the Linux installation, did you include the multimedia libraries?

this is a log
sudo apt-get update
sudo apt-get upgrade

//Buster
sudo apt-get install qt5-default
//Bullseye
//sudo apt install qtbase5-dev qtchooser qt5-qmake qtbase5-dev-tools
sudo apt-get install qtcreator
sudo apt-get install qtdeclarative5-dev
sudo apt-get install qtconnectivity5-dev //for bluetooth
sudo apt-get install qtbase5-examples
sudo apt-get install qtbase5-doc-html
To upgrade
sudo apt-get install qt5-qmake
//for Debian ?
qtbase5-dev
qtchooser
qt5-qmake
qtbase5-dev-tools

Can't see explicit multimedia installation? should I add? how it would be?

[JonB]

@jenya7
After typing apt-get install followed by qt or qt5 did you press the Tab key (twice)?

[jenya7]

@JonB said in A camera problem.:

@jenya7
After typing apt-get install followed by qt or qt5 did you press the Tab key (twice)?

thank you
sudo apt-get install qtmultimedia5-dev
it works. now all libraries are available.

[jenya7]

This is my constructor

Camera::Camera(QObject *parent) : QObject(parent)
{
    //Camera devices:

    QActionGroup *videoDevicesGroup = new QActionGroup(this);
    videoDevicesGroup->setExclusive(true);
    const QList<QCameraInfo> availableCameras = QCameraInfo::availableCameras();
    for (const QCameraInfo &cameraInfo : availableCameras)
 {
        QAction *videoDeviceAction = new QAction(cameraInfo.description(), videoDevicesGroup);
        videoDeviceAction->setCheckable(true);
        videoDeviceAction->setData(QVariant::fromValue(cameraInfo));
        if (cameraInfo == QCameraInfo::defaultCamera())
            videoDeviceAction->setChecked(true);
    }

    connect(videoDevicesGroup, &QActionGroup::triggered, this, &Camera::updateCameraDevice);

    setCamera(QCameraInfo::defaultCamera());
}

On availableCameras I get <0 items>.

If I check the camera is alive
raspistill -o Desktop/image.jpg
it appears and I see a snapshot on the desktop.

Does the library work with a Raspberry Pi camera at all? May be I'm beating a dead horse?

[jsulm]

@jenya7 I think you will also need to install GStreamer plug-ins. On Linux Qt uses GStreamer for multimedia.

[jenya7]

@jsulm said in A camera problem.:

@jenya7 I think you will also need to install GStreamer plug-ins. On Linux Qt uses GStreamer for multimedia.

when I run
dpkg -l | grep gstreamer
I see gstreamer installed.

[jsulm]

@jenya7 said in A camera problem.:

I see gstreamer installed

What exactly is installed? There are many GStreamer plug-ins which may be needed.

[jenya7]

@jsulm said in A camera problem.:

@jenya7 said in A camera problem.:

I see gstreamer installed

What exactly is installed? There are many GStreamer plug-ins which may be needed.

this is the list

ii  gstreamer1.0-alsa:armhf               1.14.4-2+deb10u1                        armhf        GStreamer plugin for ALSA
ii  gstreamer1.0-gtk3:armhf               1.14.4-1+rpt1+deb10u1                   armhf        GStreamer plugin for GTK+3
ii  gstreamer1.0-libav:armhf              1.15.0.1+git20180723+db823502-2+deb10u1 armhf        libav plugin for GStreamer
ii  gstreamer1.0-omx                      1.14.4-1+rpt1                           armhf        GStreamer OpenMAX plugins
ii  gstreamer1.0-omx-rpi                  1.14.4-1+rpt1                           armhf        OpenMax plugins for GStreamer
ii  gstreamer1.0-omx-rpi-config           1.14.4-1+rpt1                           armhf        OpenMax plugins for GStreamer
ii  gstreamer1.0-plugins-bad:armhf        1.14.4-1+rvt+deb10u2                    armhf        GStreamer plugins from the "bad" set
ii  gstreamer1.0-plugins-base:armhf       1.14.4-2+deb10u1                        armhf        GStreamer plugins from the "base" set
ii  gstreamer1.0-plugins-good:armhf       1.14.4-1+rpt1+deb10u1                   armhf        GStreamer plugins from the "good" set
ii  gstreamer1.0-x:armhf                  1.14.4-2+deb10u1                        armhf        GStreamer plugins for X11 and Pango
ii  libgstreamer-gl1.0-0:armhf            1.14.4-2+deb10u1                        armhf        GStreamer GL libraries
ii  libgstreamer-plugins-bad1.0-0:armhf   1.14.4-1+rvt+deb10u2                    armhf        GStreamer libraries from the "bad" set
ii  libgstreamer-plugins-base1.0-0:armhf  1.14.4-2+deb10u1                        armhf        GStreamer libraries from the "base" set
ii  libgstreamer1.0-0:armhf               1.14.4-1                                armhf        Core GStreamer libraries and elements
ii  libreoffice-avmedia-backend-gstreamer 1:6.1.5-3+rpi1+deb10u7+rpt1             armhf        GStreamer backend for LibreOffice

I really don't know if it's a complete list or a right version.

[jsulm]

@jenya7 said in A camera problem.:

or a right version

That depends on the Qt version you're using.
Try to also install gstreamer1.0-plugins-ugly, but I don't know whether this will help.

[jenya7]

@jsulm said in A camera problem.:

@jenya7 said in A camera problem.:

or a right version

That depends on the Qt version you're using.
Try to also install gstreamer1.0-plugins-ugly, but I don't know whether this will help.

I found it out! It's not enough to install library
sudo apt-get install qtmultimedia5-dev
One should add plugins also
sudo apt-get install libqt5multimedia5-plugins

Now it founds the camera. But how do I refer to it later on? There are no fields like name or id or something
at least on debug level

availableCameras	<1 items>	QList<QCameraInfo>
    [0]	@0x1027c8	QCameraInfo
        d	@0x1027c8	QSharedPointer<QCameraInfoPrivate>
			data	@0x10cd88	QCameraInfoPrivate
			weakref	2	int
			strongref	2	int
	availableCameras@1	<optimized out>	
	cameraInfo	@0x1027c8	QCameraInfo &
		d	@0x1027c8	QSharedPointer<QCameraInfoPrivate>
			data	@0x10cd88	QCameraInfoPrivate
			weakref	2	int
			strongref	2	int
	cameraInfo@1	@0x1027c8	QCameraInfo &
		d	@0x1027c8	QSharedPointer<QCameraInfoPrivate>
			data	@0x10cd88	QCameraInfoPrivate
			weakref	2	int
			strongref	2	int

QCameraInfo::defaultCamera()		QCameraInfo
		d		QSharedPointer<QCameraInfoPrivate>
			data	@0x111438	QCameraInfoPrivate
			weakref	1	int
			strongref	1	int

[jsulm]

@jenya7 said in A camera problem.:

There are no fields like name or id or something

There is: https://doc.qt.io/qt-5/qcamerainfo.html#deviceName

[jenya7]

@jsulm said in A camera problem.:

@jenya7 said in A camera problem.:

There are no fields like name or id or something

There is: https://doc.qt.io/qt-5/qcamerainfo.html#deviceName

I see. Thank you. I'll try to get it going.

[jenya7]

something eluding me
To take a shot

void Camera::takeImage()

Then on

connect(m_imageCapture.data(), &QCameraImageCapture::imageCaptured, this, &Camera::processCapturedImage);

void Camera::processCapturedImage(int requestId, const QImage& img)
{
    Q_UNUSED(requestId);
    QImage scaledImage = 100, 100,
                                    Qt::KeepAspectRatio,
                                    Qt::SmoothTransformation);

    ui->lastImagePreviewLabel->setPixmap(QPixmap::fromImage(scaledImage));

    // Display captured image for 4 seconds.
    displayCapturedImage();
    QTimer::singleShot(4000, this, &Camera::displayViewfinder);
}

But where the image actually stored?

[SGaist]

Hi,

Unless you configure the capture to capture to file, its just going to be in the buffer. You can still save it yourself though.

[jenya7]

@SGaist said in A camera problem.:

Hi,

Unless you configure the capture to capture to file, its just going to be in the buffer. You can still save it yourself though.

How do I do that? I see m_imageCapture but no property or method to set a path to a file.
And where the buffer located?

[SGaist]

The buffer just means it's in memory. You'll get a frame to process and then it's up to you to save it.

[jenya7]

@SGaist said in A camera problem.:

The buffer just means it's in memory. You'll get a frame to process and then it's up to you to save it.

After

g_camera.SetCaptureMode(QCamera::CaptureMode::CaptureStillImage);
g_camera.takeImage();

Nothing happens. I didn't get to

void Camera::processCapturedImage(int requestId, const QImage& img)

or

void Camera::imageSaved(int id, const QString &fileName)

How do I know where is the image (if it was taken at all)?

[jsulm]

@jenya7 Did you connect a slot to https://doc.qt.io/qt-5/qcamera.html#errorOccurred to see whether you get any errors? Same for https://doc.qt.io/qt-5/qcameraimagecapture.html#error-1
You can get the cptured image using this signal: https://doc.qt.io/qt-5/qcameraimagecapture.html#imageAvailable