plugin: add BeatTracker

Replaces beat-detector.cpp

3 files changed, 160 insertions, 2 deletions

diff --git a/plugin/src/Caelestia/CMakeLists.txt b/plugin/src/Caelestia/CMakeLists.txt
index 6461027..cc8e567 100644
--- a/plugin/src/Caelestia/CMakeLists.txt
+++ b/plugin/src/Caelestia/CMakeLists.txt
@@ -1,5 +1,6 @@
 find_package(PkgConfig REQUIRED)
 pkg_check_modules(QALCULATE REQUIRED libqalculate)
+pkg_check_modules(AUBIO REQUIRED aubio)
 
 qt_add_qml_module(caelestia
     URI Caelestia
@@ -9,6 +10,7 @@ qt_add_qml_module(caelestia
         cachingimagemanager.hpp cachingimagemanager.cpp
         filesystemmodel.hpp filesystemmodel.cpp
         qalculator.hpp qalculator.cpp
+        beattracker.hpp beattracker.cpp
 )
 
 qt_query_qml_module(caelestia
@@ -28,5 +30,8 @@ install(TARGETS "${module_plugin_target}" LIBRARY DESTINATION "${module_dir}" RU
 install(FILES "${module_qmldir}" DESTINATION "${module_dir}")
 install(FILES "${module_typeinfo}" DESTINATION "${module_dir}")
 
-target_include_directories(caelestia SYSTEM PRIVATE ${QALCULATE_INCLUDE_DIRS})
-target_link_libraries(caelestia PRIVATE Qt::Core Qt::Qml Qt::Gui Qt::Concurrent ${QALCULATE_LIBRARIES})
+target_include_directories(caelestia SYSTEM PRIVATE ${QALCULATE_INCLUDE_DIRS} ${AUBIO_INCLUDE_DIRS})
+target_link_libraries(caelestia PRIVATE
+    Qt::Core Qt::Qml Qt::Gui Qt::Concurrent Qt::Multimedia
+    ${QALCULATE_LIBRARIES} ${AUBIO_LIBRARIES}
+)
diff --git a/plugin/src/Caelestia/beattracker.cpp b/plugin/src/Caelestia/beattracker.cpp
new file mode 100644
index 0000000..434c335
--- /dev/null
+++ b/plugin/src/Caelestia/beattracker.cpp
@@ -0,0 +1,106 @@
+#include "beattracker.hpp"
+
+#include <QAudioSource>
+#include <QDebug>
+#include <QIODevice>
+#include <QMediaDevices>
+#include <QObject>
+#include <aubio/aubio.h>
+
+BeatTracker::BeatTracker(uint_t sampleRate, uint_t hopSize, QObject* parent)
+    : QObject(parent)
+    , m_tempo(new_aubio_tempo("default", 1024, hopSize, sampleRate))
+    , m_in(new_fvec(hopSize))
+    , m_out(new_fvec(2))
+    , m_hopSize(hopSize)
+    , m_bpm(120)
+    , m_refCount(0) {
+    QAudioFormat format;
+    format.setSampleRate(static_cast<int>(sampleRate));
+    format.setChannelCount(1);
+    format.setSampleFormat(QAudioFormat::Int16);
+
+    m_source = new QAudioSource(QMediaDevices::defaultAudioInput(), format, this);
+    connect(m_source, &QAudioSource::stateChanged, this, &BeatTracker::handleStateChanged);
+};
+
+BeatTracker::~BeatTracker() {
+    del_aubio_tempo(m_tempo);
+    del_fvec(m_in);
+    del_fvec(m_out);
+
+    m_source->stop();
+    delete m_source;
+}
+
+smpl_t BeatTracker::bpm() const {
+    return m_bpm;
+}
+
+int BeatTracker::refCount() const {
+    return m_refCount;
+}
+
+void BeatTracker::setRefCount(int refCount) {
+    if (m_refCount == refCount) {
+        return;
+    }
+
+    m_refCount = refCount;
+    emit refCountChanged();
+
+    if (m_refCount == 0) {
+        stop();
+    } else if (!m_device) {
+        start();
+    }
+}
+
+void BeatTracker::start() {
+    m_device = m_source->start();
+    connect(m_device, &QIODevice::readyRead, this, &BeatTracker::process);
+}
+
+void BeatTracker::stop() {
+    m_source->stop();
+    m_device = nullptr;
+}
+
+void BeatTracker::process() {
+    const QByteArray data = m_device->readAll();
+    const int16_t* samples = reinterpret_cast<const int16_t*>(data.constData());
+    const size_t count = static_cast<size_t>(data.size()) / sizeof(int16_t);
+
+    for (size_t i = 0; i < count; ++i) {
+        m_in->data[i % m_hopSize] = samples[i] / 32768.0f;
+        if ((i + 1) % m_hopSize == 0) {
+            aubio_tempo_do(m_tempo, m_in, m_out);
+            if (m_out->data[0] != 0.0f) {
+                m_bpm = aubio_tempo_get_bpm(m_tempo);
+                emit bpmChanged();
+                emit beat(m_bpm);
+            }
+        }
+    }
+}
+
+void BeatTracker::handleStateChanged(QtAudio::State state) const {
+    if (state == QtAudio::StoppedState && m_source->error() != QtAudio::NoError) {
+        switch (m_source->error()) {
+        case QtAudio::OpenError:
+            qWarning() << "BeatTracker: failed to open audio device";
+            break;
+        case QtAudio::IOError:
+            qWarning() << "BeatTracker: an error occurred during read/write of audio device";
+            break;
+        case QtAudio::UnderrunError:
+            qWarning() << "BeatTracker: audio data is not being fed to audio device fast enough";
+            break;
+        case QtAudio::FatalError:
+            qCritical() << "BeatTracker: fatal error in audio device";
+            break;
+        default:
+            break;
+        }
+    }
+}
\ No newline at end of file
diff --git a/plugin/src/Caelestia/beattracker.hpp b/plugin/src/Caelestia/beattracker.hpp
new file mode 100644
index 0000000..a300c20
--- /dev/null
+++ b/plugin/src/Caelestia/beattracker.hpp
@@ -0,0 +1,47 @@
+#pragma once
+
+#include <QAudioSource>
+#include <QIODevice>
+#include <QObject>
+#include <aubio/aubio.h>
+#include <qqmlintegration.h>
+
+class BeatTracker : public QObject {
+    Q_OBJECT
+    QML_ELEMENT
+    QML_SINGLETON
+
+    Q_PROPERTY(smpl_t bpm READ bpm NOTIFY bpmChanged)
+    Q_PROPERTY(int refCount READ refCount WRITE setRefCount NOTIFY refCountChanged)
+
+public:
+    explicit BeatTracker(uint_t sampleRate = 44100, uint_t hopSize = 512, QObject* parent = nullptr);
+    ~BeatTracker();
+
+    [[nodiscard]] smpl_t bpm() const;
+
+    [[nodiscard]] int refCount() const;
+    void setRefCount(int refCount);
+
+signals:
+    void bpmChanged();
+    void refCountChanged();
+    void beat(smpl_t bpm);
+
+private:
+    QAudioSource* m_source;
+    QIODevice* m_device;
+
+    aubio_tempo_t* m_tempo;
+    fvec_t* m_in;
+    fvec_t* m_out;
+    uint_t m_hopSize;
+
+    smpl_t m_bpm;
+    int m_refCount;
+
+    void start();
+    void stop();
+    void process();
+    void handleStateChanged(QtAudio::State state) const;
+};