implemented new audio monitor widget

app/widget/CMakeLists.txt

@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+add_subdirectory(audiomonitor)
 add_subdirectory(columnedgridlayout)
 add_subdirectory(flowlayout)
 add_subdirectory(footagecombobox)

app/widget/audiomonitor/CMakeLists.txt

@@ -0,0 +1,22 @@
+# Olive - Non-Linear Video Editor
+# Copyright (C) 2019 Olive Team
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+set(OLIVE_SOURCES
+  ${OLIVE_SOURCES}
+  widget/audiomonitor/audiomonitor.h
+  widget/audiomonitor/audiomonitor.cpp
+  PARENT_SCOPE
+)

app/widget/audiomonitor/audiomonitor.cpp

@@ -0,0 +1,147 @@
+#include "audiomonitor.h"
+
+#include <QAudio>
+#include <QDebug>
+#include <QPainter>
+
+#include "audio/audiomanager.h"
+#include "common/qtversionabstraction.h"
+
+const int kDecibelStep = 6;
+const int kDecibelMinimum = -200;
+const int kClearTimerInterval = 500;
+
+AudioMonitor::AudioMonitor(QWidget *parent) :
+  QWidget(parent)
+{
+  clear_timer_.setInterval(kClearTimerInterval);
+
+  connect(AudioManager::instance(), SIGNAL(SentSamples(QVector<double>)), this, SLOT(SetValues(QVector<double>)));
+  connect(&clear_timer_, SIGNAL(timeout()), this, SLOT(Clear()));
+  connect(&clear_timer_, SIGNAL(timeout()), &clear_timer_, SLOT(stop()));
+}
+
+void AudioMonitor::SetValues(QVector<double> values)
+{
+  values_ = values;
+
+  if (values_.size() != peaked_.size()) {
+    peaked_.resize(values_.size());
+    peaked_.fill(false);
+  }
+
+  clear_timer_.stop();
+  clear_timer_.start();
+
+  update();
+}
+
+void AudioMonitor::Clear()
+{
+  values_.fill(0);
+  update();
+}
+
+void AudioMonitor::paintEvent(QPaintEvent *)
+{
+  int channels = values_.size();
+
+  if (channels == 0) {
+    return;
+  }
+
+  QPainter p(this);
+  QFontMetrics fm = p.fontMetrics();
+
+  int peaks_y = 0;
+  int peaks_height = fm.height();
+
+  QRect db_labels_rect = rect();
+  db_labels_rect.setWidth(QFontMetricsWidth(p.fontMetrics(), "-00"));
+  db_labels_rect.adjust(0, peaks_height, 0, 0);
+
+  QRect full_meter_rect = rect();
+  full_meter_rect.adjust(db_labels_rect.width(), peaks_height, 0, 0);
+
+  // Draw decibel markings
+  QRect last_db_marking_rect;
+
+  for (int i=0;i>=kDecibelMinimum;i-=kDecibelStep) {
+    QString db_label;
+
+    if (i <= kDecibelMinimum) {
+      db_label = "-∞";
+    } else {
+      db_label = QString("%1").arg(i);
+    }
+
+    qreal log_val = QAudio::convertVolume(i, QAudio::DecibelVolumeScale, QAudio::LogarithmicVolumeScale);
+
+    QRect db_marking_rect = db_labels_rect;
+    db_marking_rect.adjust(0, db_labels_rect.y() + db_labels_rect.height() - qRound(log_val * db_labels_rect.height()), 0, 0);
+    db_marking_rect.setHeight(fm.height());
+
+    // Prevent any dB markings overlapping
+    if (i == 0 || !db_marking_rect.intersects(last_db_marking_rect)) {
+      p.drawText(db_marking_rect, Qt::AlignRight, db_label);
+      p.drawLine(db_marking_rect.topLeft(), db_marking_rect.topRight());
+
+      last_db_marking_rect = db_marking_rect;
+    }
+  }
+
+  QLinearGradient g(full_meter_rect.topLeft(), full_meter_rect.bottomLeft());
+  g.setStops({
+               QGradientStop(0.0, Qt::red),
+               QGradientStop(0.25, Qt::yellow),
+               QGradientStop(1.0, Qt::green)
+             });
+
+  int channel_width = full_meter_rect.width() / channels;
+
+  for (int i=0;i<channels;i++) {
+    int channel_x = full_meter_rect.x() + channel_width * i;
+
+    QRect peaks_rect(channel_x, peaks_y, channel_width, peaks_height);
+
+    QRect meter_rect = full_meter_rect;
+    meter_rect.setX(channel_x);
+    meter_rect.setWidth(channel_width);
+
+    p.setPen(Qt::black);
+
+    // Draw peak rects
+    p.setBrush(Qt::red);
+    p.drawRect(peaks_rect);
+
+    // Draw gradient meter
+    p.setBrush(g);
+    p.drawRect(meter_rect);
+
+    // Draw inverted semi-transparent black overlay depending on information
+    p.setPen(Qt::NoPen);
+
+    // Validate value and whether it peaked
+    double vol = values_.at(i);
+    if (vol > 1.0) {
+      peaked_[i] = true;
+    }
+
+    // Convert val to logarithmic scale
+    vol = QAudio::convertVolume(vol, QAudio::LinearVolumeScale, QAudio::LogarithmicVolumeScale);
+
+    p.setBrush(QColor(0, 0, 0, 128));
+
+    meter_rect.adjust(0, 0, 0, -qRound(meter_rect.height() * vol));
+    p.drawRect(meter_rect);
+
+    if (!peaked_.at(i))
+      p.drawRect(peaks_rect);
+  }
+}
+
+void AudioMonitor::mousePressEvent(QMouseEvent *)
+{
+  peaked_.fill(false);
+  update();
+}

app/widget/audiomonitor/audiomonitor.h

@@ -0,0 +1,28 @@
+#ifndef AUDIOMONITORWIDGET_H
+#define AUDIOMONITORWIDGET_H
+
+#include <QTimer>
+#include <QWidget>
+
+class AudioMonitor : public QWidget
+{
+  Q_OBJECT
+public:
+  AudioMonitor(QWidget* parent = nullptr);
+
+public slots:
+  void SetValues(QVector<double> values);
+  void Clear();
+
+protected:
+  virtual void paintEvent(QPaintEvent* event) override;
+  virtual void mousePressEvent(QMouseEvent* event) override;
+
+private:
+  QVector<double> values_;
+  QVector<bool> peaked_;
+
+  QTimer clear_timer_;
+};
+
+#endif // AUDIOMONITORWIDGET_H