Qt 5.9 | Qt Multimedia | Camera Example | videosettings.cpp Example File

Qt 5.9.4 Reference Documentation

# videosettings.cpp Example File

multimediawidgets/camera/videosettings.cpp

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      #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);

          //audio codecs
          ui->audioCodecBox->addItem(tr("Default audio codec"), QVariant(QString()));
          const QStringList supportedAudioCodecs =  mediaRecorder->supportedAudioCodecs();
          for (const QString &codecName : supportedAudioCodecs) {
              QString description = mediaRecorder->audioCodecDescription(codecName);
              ui->audioCodecBox->addItem(codecName + ": " + description, QVariant(codecName));
          }

          //sample rate:
          const QList<int>supportedAudioSampleRates = mediaRecorder->supportedAudioSampleRates();
          for (int sampleRate : supportedAudioSampleRates)
              ui->audioSampleRateBox->addItem(QString::number(sampleRate), QVariant(sampleRate));

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

          //video codecs
          ui->videoCodecBox->addItem(tr("Default video codec"), QVariant(QString()));
          const QStringList supportedVideoCodecs = mediaRecorder->supportedVideoCodecs();
          for (const QString &codecName : 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"));
          const QList<QSize> supportedResolutions = mediaRecorder->supportedResolutions();
          for (const QSize &resolution : supportedResolutions) {
              ui->videoResolutionBox->addItem(QString("%1x%2").arg(resolution.width()).arg(resolution.height()),
                                              QVariant(resolution));
          }

          ui->videoFramerateBox->addItem(tr("Default"));
          const QList<qreal> supportedFrameRates = mediaRecorder->supportedFrameRates();
          for (qreal 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()));
          const QStringList formats = mediaRecorder->supportedContainers();
          for (const QString &format : formats) {
              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)
      {
          selectComboBoxItem(ui->audioCodecBox, QVariant(audioSettings.codec()));
          selectComboBoxItem(ui->audioSampleRateBox, QVariant(audioSettings.sampleRate()));
          ui->audioQualitySlider->setValue(audioSettings.quality());
      }

      QVideoEncoderSettings VideoSettings::videoSettings() const
      {
          QVideoEncoderSettings settings = mediaRecorder->videoSettings();
          settings.setCodec(boxValue(ui->videoCodecBox).toString());
          settings.setQuality(QMultimedia::EncodingQuality(ui->videoQualitySlider->value()));
          settings.setResolution(boxValue(ui->videoResolutionBox).toSize());
          settings.setFrameRate(boxValue(ui->videoFramerateBox).value<qreal>());

          return settings;
      }

      void VideoSettings::setVideoSettings(const QVideoEncoderSettings &videoSettings)
      {
          selectComboBoxItem(ui->videoCodecBox, QVariant(videoSettings.codec()));
          selectComboBoxItem(ui->videoResolutionBox, QVariant(videoSettings.resolution()));
          ui->videoQualitySlider->setValue(videoSettings.quality());

          //special case for frame rate
          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;
              }
          }
      }

      QString VideoSettings::format() const
      {
          return boxValue(ui->containerFormatBox).toString();
      }

      void VideoSettings::setFormat(const QString &format)
      {
          selectComboBoxItem(ui->containerFormatBox, QVariant(format));
      }

      QVariant VideoSettings::boxValue(const QComboBox *box) const
      {
          int idx = box->currentIndex();
          if (idx == -1)
              return QVariant();

          return box->itemData(idx);
      }

      void VideoSettings::selectComboBoxItem(QComboBox *box, const QVariant &value)
      {
          for (int i = 0; i < box->count(); ++i) {
              if (box->itemData(i) == value) {
                  box->setCurrentIndex(i);
                  break;
              }
          }
      }