C++ Qt unresolved external symbol "public: virtual __thiscall

[GGILOYAN]

Please help
I have this class

videosettings.h
@#ifndef VIDEOSETTINGS_H
#define VIDEOSETTINGS_H
#include <QDialog>
#include <QAudioEncoderSettings>
#include <QVideoEncoderSettings>

class QComboBox;
class QMediaRecorder;
namespace Ui { class VideoSettingsUi; }

class VideoSettings : public QDialog
{
Q_OBJECT

public:
VideoSettings(QMediaRecorder *mediaRecorder, QWidget *parent = 0);
~VideoSettings();

QAudioEncoderSettings audioSettings() const;
void setAudioSettings(const QAudioEncoderSettings&);

void setVideoSettings(const QVideoEncoderSettings&);

protected:
void changeEvent(QEvent *e);

private:
QVariant boxValue(const QComboBox*) const;
Ui::VideoSettingsUi *ui;
QMediaRecorder *mediaRecorder;
};

#endif

videosettings.cpp

@#include "videosettings.h"
#include "ui_videosettings.h"

#include <QComboBox>
#include <QDebug>
#include <QMediaRecorder>
#include <QMediaService>

VideoSettings::VideoSettings(QMediaRecorder *mediaRecorder, QWidget *parent) :
QDialog(parent),
ui(new Ui::VideoSettingsUi),
mediaRecorder(mediaRecorder)
{
ui->setupUi(this);
ui->audioCodecBox->addItem(tr("Default audio codec"), QVariant(QString()));
foreach (const QString &codecName, mediaRecorder->supportedAudioCodecs()) {
QString description = mediaRecorder->audioCodecDescription(codecName);
ui->audioCodecBox->addItem(codecName+": "+description, QVariant(codecName));
}

foreach (int sampleRate, mediaRecorder->supportedAudioSampleRates()) {
    ui->audioSampleRateBox->addItem(QString::number(sampleRate), QVariant(sampleRate));
}

ui->audioQualitySlider->setRange(0, int(QMultimedia::VeryHighQuality));

ui->videoCodecBox->addItem(tr("Default video codec"), QVariant(QString()));
foreach (const QString &codecName, mediaRecorder->supportedVideoCodecs()) {
    QString description = mediaRecorder->videoCodecDescription(codecName);
    ui->videoCodecBox->addItem(codecName+": "+description, QVariant(codecName));
}

ui->videoQualitySlider->setRange(0, int(QMultimedia::VeryHighQuality));

ui->videoResolutionBox->addItem(tr("Default"));
QList<QSize> supportedResolutions = mediaRecorder->supportedResolutions();
foreach (const QSize &resolution, supportedResolutions) {
    ui->videoResolutionBox->addItem(QString("%1x%2").arg(resolution.width()).arg(resolution.height()),
                                    QVariant(resolution));
}

ui->videoFramerateBox->addItem(tr("Default"));
QList<qreal> supportedFrameRates = mediaRecorder->supportedFrameRates();
qreal rate;
foreach (rate, supportedFrameRates) {
    QString rateString = QString("%1").arg(rate, 0, 'f', 2);
    ui->videoFramerateBox->addItem(rateString, QVariant(rate));
}

//containers
ui->containerFormatBox->addItem(tr("Default container"), QVariant(QString()));
foreach (const QString &format, mediaRecorder->supportedContainers()) {
    ui->containerFormatBox->addItem(format+":"+mediaRecorder->containerDescription(format),
                                    QVariant(format));
}

}

VideoSettings::~VideoSettings()
{
delete ui;
}

void VideoSettings::changeEvent(QEvent *e)
{
QDialog::changeEvent(e);
switch (e->type()) {
case QEvent::LanguageChange:
ui->retranslateUi(this);
break;
default:
break;
}
}

QAudioEncoderSettings VideoSettings::audioSettings() const
{
QAudioEncoderSettings settings = mediaRecorder->audioSettings();
settings.setCodec(boxValue(ui->audioCodecBox).toString());
settings.setQuality(QMultimedia::EncodingQuality(ui->audioQualitySlider->value()));
settings.setSampleRate(boxValue(ui->audioSampleRateBox).toInt());
return settings;
}

void VideoSettings::setAudioSettings(const QAudioEncoderSettings &audioSettings)
{
ui->audioQualitySlider->setValue(audioSettings.quality());
}
void VideoSettings::setVideoSettings(const QVideoEncoderSettings &videoSettings)
{
ui->videoQualitySlider->setValue(videoSettings.quality());
for (int i = 0; i < ui->videoFramerateBox->count(); ++i) {
qreal itemRate = ui->videoFramerateBox->itemData(i).value<qreal>();
if (qFuzzyCompare(itemRate, videoSettings.frameRate())) {
ui->videoFramerateBox->setCurrentIndex(i);
break;
}
}
}
QVariant VideoSettings::boxValue(const QComboBox *box) const
{
int idx = box->currentIndex();
if (idx == -1)
return QVariant();

return box->itemData(idx);

}
@
and this class instance created and called from another class method
@void Camera::configureVideoSettings()
{
VideoSettings settingsDialog(mediaRecorder);
settingsDialog.setAudioSettings(audioSettings);
settingsDialog.setVideoSettings(videoSettings);
}@

When I compile this code I get the following errors

camera.obj : error LNK2019: unresolved external symbol "public: virtual __thiscall VideoSettings::~VideoSettings(void)" (??1VideoSettings@@UAE@XZ) referenced in function "private: void __thiscall Camera::configureVideoSettings(void)" (?configureVideoSettings@Camera@@AAEXXZ)
camera.obj : error LNK2019: unresolved external symbol "public: void __thiscall VideoSettings::setFormat(class QString const &)" (?setFormat@VideoSettings@@QAEXABVQString@@@Z) referenced in function "private: void __thiscall Camera::configureVideoSettings(void)" (?configureVideoSettings@Camera@@AAEXXZ)
camera.obj : error LNK2019: unresolved external symbol "public: void __thiscall VideoSettings::setVideoSettings(class QVideoEncoderSettings const &)" (?setVideoSettings@VideoSettings@@QAEXABVQVideoEncoderSettings@@@Z) referenced in function "private: void __thiscall Camera::configureVideoSettings(void)" (?configureVideoSettings@Camera@@AAEXXZ)

[hskoglund]

Hi,
inside Camera::configureVideoSettings() I dont' see your call to settingsDialog.setFormat(string), u sure it's the code above that gives those errors?

Also, you can check if this is just a linking error, maybe by merging the two files videosettings.cpp and camera.cpp into just one .cpp file.

[GGILOYAN]

Thanks, but I downloaded this files and don't change nothing

http://qt-project.org/doc/qt-5.0/qtmultimedia/multimediawidgets-camera.html

videosettings.cpp and camera.cpp don't included in one .cpp.

[hskoglund]

Aha sorry I've not looked so much at Qt's samples!

Anyway, I just found your code in my installation of Qt in Windows 7, in C:\Qt\5.2.1\msvc2012\examples\multimediawidgets\camera

Double-clicked on the camera.pro file, it compiled and run just fine (except that I don't have any camera)

So, maybe because you have another version of Windows and Visual Studio?

[GGILOYAN]

I am using Windows7 and VS 2010.
I saw the example.

Thank you so much!