From 838c12bce8d0d48ef50f485e6f611990742d7b8f Mon Sep 17 00:00:00 2001
From: Yoann Lopes <yoann.lopes@qt.io>
Date: Thu, 19 May 2016 16:38:11 +0200
Subject: Use new volume conversion API in examples.

Volumes sliders are now scaled cubically so that loudness changes
are perceived linearly.

Change-Id: Ibf00d6a97d872063d92457493417be5eb42f79ac
Reviewed-by: Christian Stromme <christian.stromme@qt.io>
---
 examples/multimedia/audioinput/audioinput.cpp       | 14 +++++++++++---
 examples/multimedia/audiooutput/audiooutput.cpp     | 15 ++++++++++++---
 .../multimediawidgets/player/playercontrols.cpp     | 21 +++++++++++++++++----
 examples/multimediawidgets/player/playercontrols.h  |  1 +
 4 files changed, 41 insertions(+), 10 deletions(-)

(limited to 'examples')

diff --git a/examples/multimedia/audioinput/audioinput.cpp b/examples/multimedia/audioinput/audioinput.cpp
index fd73d4f16..da5966598 100644
--- a/examples/multimedia/audioinput/audioinput.cpp
+++ b/examples/multimedia/audioinput/audioinput.cpp
@@ -315,7 +315,10 @@ void InputTest::initializeAudio()
 void InputTest::createAudioInput()
 {
     m_audioInput = new QAudioInput(m_device, m_format, this);
-    m_volumeSlider->setValue(m_audioInput->volume() * 100);
+    qreal initialVolume = QAudio::convertVolume(m_audioInput->volume(),
+                                                QAudio::LinearVolumeScale,
+                                                QAudio::CubicVolumeScale);
+    m_volumeSlider->setValue(qRound(initialVolume * 100));
     m_audioInfo->start();
     m_audioInput->start(m_audioInfo);
 }
@@ -386,6 +389,11 @@ void InputTest::deviceChanged(int index)
 
 void InputTest::sliderChanged(int value)
 {
-    if (m_audioInput)
-        m_audioInput->setVolume(qreal(value) / 100);
+    if (m_audioInput) {
+        qreal linearVolume =  QAudio::convertVolume(value / qreal(100),
+                                                    QAudio::CubicVolumeScale,
+                                                    QAudio::LinearVolumeScale);
+
+        m_audioInput->setVolume(linearVolume);
+    }
 }
diff --git a/examples/multimedia/audiooutput/audiooutput.cpp b/examples/multimedia/audiooutput/audiooutput.cpp
index a00ffbb00..79e70bdc2 100644
--- a/examples/multimedia/audiooutput/audiooutput.cpp
+++ b/examples/multimedia/audiooutput/audiooutput.cpp
@@ -250,7 +250,11 @@ void AudioTest::createAudioOutput()
     m_audioOutput = new QAudioOutput(m_device, m_format, this);
     m_generator->start();
     m_audioOutput->start(m_generator);
-    m_volumeSlider->setValue(int(m_audioOutput->volume()*100.0f));
+
+    qreal initialVolume = QAudio::convertVolume(m_audioOutput->volume(),
+                                                QAudio::LinearVolumeScale,
+                                                QAudio::CubicVolumeScale);
+    m_volumeSlider->setValue(qRound(initialVolume * 100));
 }
 
 AudioTest::~AudioTest()
@@ -270,8 +274,13 @@ void AudioTest::deviceChanged(int index)
 
 void AudioTest::volumeChanged(int value)
 {
-    if (m_audioOutput)
-        m_audioOutput->setVolume(qreal(value/100.0f));
+    if (m_audioOutput) {
+        qreal linearVolume =  QAudio::convertVolume(value / qreal(100),
+                                                    QAudio::CubicVolumeScale,
+                                                    QAudio::LinearVolumeScale);
+
+        m_audioOutput->setVolume(linearVolume);
+    }
 }
 
 void AudioTest::pushTimerExpired()
diff --git a/examples/multimediawidgets/player/playercontrols.cpp b/examples/multimediawidgets/player/playercontrols.cpp
index 07aa2e731..80abf59b6 100644
--- a/examples/multimediawidgets/player/playercontrols.cpp
+++ b/examples/multimediawidgets/player/playercontrols.cpp
@@ -45,6 +45,7 @@
 #include <QStyle>
 #include <QToolButton>
 #include <QComboBox>
+#include <QAudio>
 
 PlayerControls::PlayerControls(QWidget *parent)
     : QWidget(parent)
@@ -87,7 +88,7 @@ PlayerControls::PlayerControls(QWidget *parent)
     volumeSlider = new QSlider(Qt::Horizontal, this);
     volumeSlider->setRange(0, 100);
 
-    connect(volumeSlider, SIGNAL(sliderMoved(int)), this, SIGNAL(changeVolume(int)));
+    connect(volumeSlider, SIGNAL(valueChanged(int)), this, SLOT(onVolumeSliderValueChanged()));
 
     rateBox = new QComboBox(this);
     rateBox->addItem("0.5x", QVariant(0.5));
@@ -138,13 +139,20 @@ void PlayerControls::setState(QMediaPlayer::State state)
 
 int PlayerControls::volume() const
 {
-    return volumeSlider ? volumeSlider->value() : 0;
+    qreal linearVolume =  QAudio::convertVolume(volumeSlider->value() / qreal(100),
+                                                QAudio::CubicVolumeScale,
+                                                QAudio::LinearVolumeScale);
+
+    return qRound(linearVolume * 100);
 }
 
 void PlayerControls::setVolume(int volume)
 {
-    if (volumeSlider)
-        volumeSlider->setValue(volume);
+    qreal cubicVolume = QAudio::convertVolume(volume / qreal(100),
+                                               QAudio::LinearVolumeScale,
+                                               QAudio::CubicVolumeScale);
+
+    volumeSlider->setValue(qRound(cubicVolume * 100));
 }
 
 bool PlayerControls::isMuted() const
@@ -203,3 +211,8 @@ void PlayerControls::updateRate()
 {
     emit changeRate(playbackRate());
 }
+
+void PlayerControls::onVolumeSliderValueChanged()
+{
+    emit changeVolume(volume());
+}
diff --git a/examples/multimediawidgets/player/playercontrols.h b/examples/multimediawidgets/player/playercontrols.h
index 0ab195faa..d29a06d6c 100644
--- a/examples/multimediawidgets/player/playercontrols.h
+++ b/examples/multimediawidgets/player/playercontrols.h
@@ -82,6 +82,7 @@ private slots:
     void playClicked();
     void muteClicked();
     void updateRate();
+    void onVolumeSliderValueChanged();
 
 private:
     QMediaPlayer::State playerState;
-- 
cgit v1.2.3