How to run Camera on Linux using Qt?

Asked Feb 27 '18 at 08:08

Active Feb 27 '18 at 08:40

Viewed 946 times

I am running camera on Linux and getting an error that

defaultServiceProvider::requestService(): no service found for - "org.qt-project.qt.camera"

this is my code

Camera::Camera(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::Camera)

ui->setupUi(this);
mCamera = new QCamera(this);
recorder = new QMediaRecorder(mCamera,this);
mCameraViewfinder = new QCameraViewfinder(this);
mCameraImageCapture = new QCameraImageCapture(mCamera,this);
mLayout = new QVBoxLayout;

mCamera->setViewfinder(mCameraViewfinder);
mLayout->addWidget(mCameraViewfinder);
ui->scrollArea->setLayout(mLayout);
//mCameraViewfinder->show();
mCamera->start();

Any help?

Update:

the .pro setup:

QT += core gui multimedia multimediawidgets
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets 
TARGET = Camera 
TEMPLATE = app 
DEFINES += QT_DEPRECATED_WARNINGS 
SOURCES += \ main.cpp \ camera.cpp 
HEADERS += \ camera.h 
FORMS += \ camera.ui

edited Feb 27 '18 at 08:40

Ilya

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asked Feb 27 '18 at 08:08

Ramiz

What output you get for `ls -l /dev/video*` – Mohammad Kanan Feb 27 '18 at 08:26
I am trying to know if you have `/dev/video0` device in your Linux system – Mohammad Kanan Feb 27 '18 at 08:53
@MohammadKanan I dont know that.Is there any way to check that as I am new to Linux and Qt. – Ramiz Feb 27 '18 at 08:59
You can use _command line_ and _list_ command: `ls -l /dev/video*` – Mohammad Kanan Feb 27 '18 at 09:03
It gives me an error **No such file or directory** – Ramiz Feb 27 '18 at 09:06
Have you tested your _camera_ directly from Linux – Mohammad Kanan Feb 27 '18 at 09:08
Yes Camera is working fine by command **Cheese** – Ramiz Feb 27 '18 at 09:09
1

Which Linux you using, I guess the problem is Qt can't find the backend for the Camera, I have seen the error when using Yocto Qt. Solve it by installing right version gstream and qmultimedia module – JustWe Feb 27 '18 at 09:58
I am using Ubuntu 14 – Ramiz Feb 27 '18 at 10:00
@Ramiz, Is this a virtualbox? – Mohammad Kanan Feb 27 '18 at 10:55
No its not a virtual box – Ramiz Feb 27 '18 at 11:02
In Ubuntu, Webcam raw device is normally found as `/dev/video0` .. – Mohammad Kanan Feb 27 '18 at 11:05
But as u I told you it gives me an error – Ramiz Feb 27 '18 at 11:08
Is it an integrated _webcam_ device or USB camera? – Mohammad Kanan Feb 27 '18 at 11:11
Its an integrated webcam that is running by cheese command terminal – Ramiz Feb 27 '18 at 11:14
Did you reboot after testing with _cheese_ ? – Mohammad Kanan Feb 27 '18 at 11:17
Yes i did reboot – Ramiz Feb 27 '18 at 11:19
1

In summery and as @Jiu suggested, Qt can't find the cam backend .. – Mohammad Kanan Feb 27 '18 at 11:21
So any solution for that? – Ramiz Feb 27 '18 at 11:22
I can't make out whats the issue. In Ubuntu17/VirtualBox I can see the _raw_ device for integrated webcam. – Mohammad Kanan Feb 27 '18 at 11:34
Is it possible that the camera backend is stored in a different device file within `/dev` in his case? – Aditya Feb 27 '18 at 15:27
duplicate https://stackoverflow.com/questions/37650773/qt-camera-example-doesnt-work and btw check the `gstream`. – JustWe Feb 28 '18 at 00:12
I have checked it but still same error **defaultServiceProvider::requestService(): no service found for - "org.qt-project.qt.camera"** – Ramiz Feb 28 '18 at 06:44

How to run Camera on Linux using Qt?

0 Answers0