WebRTC playing webcam with Qt - qt

Question

I use WebRTC for webcam playing (it's for testing webcam at my application before video calling). I do these next some WebRTC function:
////////////////////////
//initialization
{
webrtc::VoiceEngine* voe = VoiceEngine::Create();
webrtc::VoEBase* voeBase = VoEBase::GetInterface( voe );
voeBase->Init();
webrtc::VideoEngine* vie = VideoEngine::Create();
webrtc::ViEBase* vieBase = ViEBase::GetInterface( vie );
vieBase->Init();
webrtc::ViECapture* vieCapture = ViECapture::GetInterface( vie );
}
////////////////////////
// start webcam playing
void MainWindow::StartWebcamTest()
{
// creating window for playing webcam video
videoWidget = new Phonon::VideoWidget();
videoWidget->setFixedSize( 640, 480 );
videoWidget->setWindowTitle( "Test Webcam" );
char captDevName[1024], captGuidName[1024];
VoEEngineSingleton::Instance()->GetViECapture()->GetCaptureDevice( 0, captDevName, 1024, captGuidName, 1024 );
VoEEngineSingleton::Instance()->GetViECapture()->AllocateCaptureDevice( captGuidName, 1024, captureID );
testVideoChannel = VoEEngineSingleton::Instance()->GetViEBase()->CreateChannel( testVideoChannel );
if( testVideoChannel == -1 )
LOGERR << "Creating video channel error: " << VoEEngineSingleton::Instance()->GetViEBase()->LastError() << endl;
else LOGDEBUG << "Video channel created, ID = " << testVideoChannel << endl;
testAudioChannel = VoEEngineSingleton::Instance()->GetVoEBase()->CreateChannel();
if( testAudioChannel == -1 )
LOGERR << "Creating audio channel error: " << VoEEngineSingleton::Instance()->GetVoEBase()->LastError() << endl;
else LOGDEBUG << "Audio channel created, ID = " << testAudioChannel << endl;
if( VoEEngineSingleton::Instance()->GetViEBase()->ConnectAudioChannel( testVideoChannel, testAudioChannel ) != 0 )
LOGERR << "ConnectAudioChannel() error: " << VoEEngineSingleton::Instance()->GetViEBase()->LastError() << endl;
else LOGINFO << "Audio channel connected successful " << endl;
if( VoEEngineSingleton::Instance()->GetViECapture()->ConnectCaptureDevice( captureID, testVideoChannel ) != 0 )
LOGERR << "ConnectCaptureDevice() error: " << VoEEngineSingleton::Instance()->GetViEBase()->LastError() << endl;
else LOGINFO << "Capture device connected successful " << endl;
if( VoEEngineSingleton::Instance()->GetViERender()->StartRender( testVideoChannel ) != 0 )
LOGERR << "StartRender() error: " << VoEEngineSingleton::Instance()->GetViEBase()->LastError() << endl;
else LOGINFO "StartRender() successed " << endl;
if( VoEEngineSingleton::Instance()->GetViECapture()->StartCapture( captureID ) != 0 )
LOGERR << "StartCapture() error: " << VoEEngineSingleton::Instance()->GetViEBase()->LastError() << endl;
else LOGINFO << "StartCapture() successed " << endl;
videoWidget->show();
}
When I click button for playing video - webcam starts playing but videoWidget window is black empty.
What am I doing not true? And maybe I must use other Qt widget for it?

Answer 1

You have to implement video renderer in Qt. subclass webrtc::ExternalRenderer and draw the frame

Answer 2

#include <QApplication>
#include <QUrl>
#include <QWebEngineView>
class WebEnginePage: public QWebEnginePage{
Q_OBJECT
public:
WebEnginePage(QObject *parent = Q_NULLPTR):QWebEnginePage(parent){
connect(this, &WebEnginePage::featurePermissionRequested, this, &WebEnginePage::onFeaturePermissionRequested);
}
private Q_SLOTS:
void onFeaturePermissionRequested(const QUrl &securityOrigin, QWebEnginePage::Feature feature){
if(feature == QWebEnginePage::MediaAudioCapture
|| feature == QWebEnginePage::MediaVideoCapture
|| feature == QWebEnginePage::MediaAudioVideoCapture)
setFeaturePermission(securityOrigin, feature, QWebEnginePage::PermissionGrantedByUser);
else
setFeaturePermission(securityOrigin, feature, QWebEnginePage::PermissionDeniedByUser);
}
};
int main(int argc, char *argv[])
{
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QApplication app(argc, argv);
QWebEngineView view;
view.setPage(new WebEnginePage);
QUrl url = "https://appr.tc/r/386424467";
// view.setUrl(commandLineUrlArgument());
view.setUrl(url);
view.resize(1024, 750);
view.show();
return app.exec();
}
#include "main.moc"