fully functional music playback

meson.build

@@ -11,9 +11,10 @@ alsa_dep = dependency('alsa')
 
 executable(
   'waffle',
-  './src/OpusFile.cpp',
-  './src/ALSAOutput.cpp',
-  './src/AppWidget.cpp',
+  './src/player/OpusFile.cpp',
+  './src/player/ALSAOutput.cpp',
+  './src/player/Player.cpp',
+  './src/ui/AppWidget.cpp',
   './src/main.cpp',
   dependencies : [raven_dep, opus_dep, opusfile_dep, alsa_dep]
 )

src/main.cpp

@@ -1,27 +1,24 @@
 #include <iostream>
+#include <memory>
 #include "raven/Window.hpp"
 #include "raven/Application.hpp"
 #include "raven/Widget.hpp"
 #include "raven/Button.hpp"
-#include "AppWidget.hpp"
-#include "src/ALSAOutput.hpp"
-#include "src/OpusFile.hpp"
+#include "src/player/Player.hpp"
+#include "ui/AppWidget.hpp"
+#include "player/ALSAOutput.hpp"
+#include "player/OpusFile.hpp"
 
 int main()
 {
-    OpusFile file;
-    file.open("song");
-    ALSAOutput output;
-    output.open();
-    output.configure(48000, 2, 10, 100000);
-    output.play(&file);
+    Player player;
 
     Raven::Application application(true);
     auto window = application.add_window<Raven::Window>();
 
     window->spawn_window();
 
-    window->set_main_widget<AppWidget>();
+    window->set_main_widget<AppWidget>(&player);
 
     return application.run();
 }

src/player/ALSAOutput.cpp

@@ -5,8 +5,8 @@
 #include <iostream>
 
 
-int ALSAOutput::open() {
-    if (snd_pcm_open(&m_pcm, "default", SND_PCM_STREAM_PLAYBACK, 0) < 0) return -1;
+int ALSAOutput::open(std::string output_name) {
+    if (snd_pcm_open(&m_pcm, output_name.c_str(), SND_PCM_STREAM_PLAYBACK, 0) < 0) return -1;
 
     return 0;
 }
@@ -32,13 +32,17 @@ int ALSAOutput::configure(int sample_rate, int channels, int periods, float peri
     return 0;
 }
 
-int ALSAOutput::play(AbstractMusicFile *file) {
-    while (true) {
-        int16_t pcm[176400];
-        memset(pcm, 0, sizeof(pcm));
-        
-        size_t n_samples = file->read(pcm, 176400);
-
-        snd_pcm_writei(m_pcm, pcm, n_samples);
-    }
+int ALSAOutput::write(int16_t *data, size_t samples) {
+    return snd_pcm_writei(m_pcm, data, samples);
+}
+
+int ALSAOutput::drop() {
+    snd_pcm_drop(m_pcm);
+    snd_pcm_prepare(m_pcm);
+    return 0;
+}
+
+ALSAOutput::~ALSAOutput() {
+    snd_pcm_drain(m_pcm);
+    snd_pcm_close(m_pcm);
 }

src/player/ALSAOutput.hpp

@@ -1,16 +1,19 @@
 #pragma once
 
-#include "src/AbstractMusicFile.hpp"
+#include "AbstractMusicFile.hpp"
 #include <alsa/asoundlib.h>
+#include <alsa/pcm.h>
 
 
 class ALSAOutput {
 public:
     ALSAOutput() {}
+    ~ALSAOutput();
 
-    int open();
+    int open(std::string output_name);
     int configure(int sample_rate, int channels, int periods, float period_time);
-    int play(AbstractMusicFile *file);
+    int write(int16_t *data, size_t samples);
+    int drop();
 private:
     snd_pcm_t *m_pcm { nullptr };
 };

src/player/OpusFile.cpp

@@ -5,6 +5,10 @@
 #include <iostream>
 
 int OpusFile::open(std::string file_path) {
+    if (m_file != NULL) {
+        op_free(m_file);
+    }
+
     m_file = op_open_file(file_path.c_str(), NULL);
     if (m_file == NULL) return -1;
 
@@ -14,3 +18,7 @@ int OpusFile::open(std::string file_path) {
 int OpusFile::read(int16_t *pcm, int buf_size) {
     return op_read_stereo(m_file, pcm, buf_size);
 }
+
+OpusFile::~OpusFile() {
+    op_free(m_file);
+}

src/player/OpusFile.hpp

@@ -8,6 +8,7 @@
 class OpusFile : public AbstractMusicFile {
 public:
     OpusFile() {}
+    ~OpusFile();
 
     int open(std::string file_path);
     int read(int16_t *pcm, int buf_size);

src/player/Player.cpp

@@ -0,0 +1,68 @@
+#include "Player.hpp"
+#include "ALSAOutput.hpp"
+#include <thread>
+#include <iostream>
+#include <fcntl.h>
+#include <unistd.h>
+#include <exception>
+#include <mutex>
+
+void Player::start_playback_thread() {
+    m_playback_thread = new std::thread([this]() {
+        playback_loop();
+    });
+}
+
+void Player::set_file(std::shared_ptr<AbstractMusicFile> file) {
+    std::lock_guard<std::mutex> guard(m_lock);
+    m_file = file;
+    if (m_state == State::NoThreadUntilFile) {
+        {
+            std::lock_guard<std::mutex> alsa_guard(m_alsa_lock);
+            m_alsa_output->drop();
+        }
+
+        start_playback_thread();
+        m_state = State::Playing;
+    } else if (m_state == State::Playing) {
+        std::lock_guard<std::mutex> alsa_guard(m_alsa_lock);
+        m_alsa_output->drop();
+    }
+}
+
+void Player::playback_loop() {
+    while (true) {
+        int16_t pcm[176400];
+        size_t samples_read = 0;
+        
+        {
+            std::lock_guard<std::mutex> guard(m_lock);
+            samples_read = m_file->read(pcm, 176400);
+            if (samples_read < 1) {
+                m_state = State::NoThreadUntilFile;
+                return;
+            }
+        }
+
+        {
+            std::lock_guard<std::mutex> guard(m_alsa_lock);
+            m_alsa_output->write(pcm, samples_read);
+        }
+    }
+}
+
+Player::Player() {
+    m_alsa_output = new ALSAOutput();
+    m_alsa_output->open("pipewire");
+    m_alsa_output->configure(48000, 2, 1, 100000);
+}
+
+Player::~Player() {
+    if (m_alsa_output) {
+        delete m_alsa_output;
+    }
+    if (m_playback_thread) {
+        delete m_playback_thread;
+    }
+}
+

src/player/Player.hpp

@@ -0,0 +1,38 @@
+#pragma once
+
+#include "AbstractMusicFile.hpp"
+#include "ALSAOutput.hpp"
+#include <memory>
+#include <thread>
+#include <mutex>
+
+
+class Player {
+public:
+    Player();
+    ~Player();
+
+    enum class State {
+        NoThreadUntilFile,
+        Paused,
+        Playing
+    };
+
+    std::shared_ptr<AbstractMusicFile> file() { return m_file; }
+    void set_file(std::shared_ptr<AbstractMusicFile> file);
+private:
+    void playback_loop();
+    void start_playback_thread();
+
+    std::mutex m_lock;
+    /**/
+    std::thread *m_playback_thread { nullptr };
+    State m_state { State::NoThreadUntilFile };
+    std::shared_ptr<AbstractMusicFile> m_file { nullptr };
+    /**/
+
+    std::mutex m_alsa_lock;
+    /**/
+    ALSAOutput *m_alsa_output { nullptr };
+    /**/
+};

src/ui/AppWidget.cpp

@@ -9,14 +9,21 @@
 #include "raven/BoxLayout.hpp"
 #include "raven/Label.hpp"
 #include "raven/DocumentLayout.hpp"
+#include "src/player/OpusFile.hpp"
+#include "src/player/Player.hpp"
 #include <filesystem>
 
-static void populate_song_list(std::filesystem::path songs_directory, std::shared_ptr<Raven::Widget> song_list_widget) {
+static void populate_song_list(std::filesystem::path songs_directory, std::shared_ptr<Raven::Widget> song_list_widget, Player *player) {
     song_list_widget->clear_children();
     for (const auto &entry : std::filesystem::directory_iterator(songs_directory)) {
         std::string filename = entry.path().filename();
         std::string path_string = entry.path().string();
         auto button = song_list_widget->add<Raven::Button>(filename);
+        button->on_click = [player, path_string]() {
+            auto file = std::make_shared<OpusFile>();
+            file->open(path_string);
+            player->set_file(file);
+        };
     }
 }
 
@@ -38,7 +45,7 @@ void AppWidget::on_init() {
         layout->set_inherit_secondary_dimension(true);
     }
 
-    populate_song_list("/home/hippoz/music", m_song_list->target());
+    populate_song_list("/home/hippoz/music", m_song_list->target(), m_player);
 
     reflow();
     set_did_init(true);

src/ui/AppWidget.hpp

@@ -3,14 +3,17 @@
 #include "raven/ScrollContainer.hpp"
 #include "raven/Widget.hpp"
 #include "raven/TextInput.hpp"
+#include "src/player/Player.hpp"
 
 class AppWidget : public Raven::Widget {
 public:
-    AppWidget()
-        : Raven::Widget() {}
+    AppWidget(Player *player)
+        : Raven::Widget()
+        , m_player(player) {}
 
 protected:
     void on_init() override;
 private:
     std::shared_ptr<Raven::ScrollContainer> m_song_list;
+    Player *m_player;
 };