Replace RtAudio with a custom ALSA backend

Author: juzzlin

Agents.md

@@ -13,7 +13,7 @@ The project follows a layered architecture to ensure separation of concerns:
     - **`command/`**: Implementation of the Command Pattern for Undo/Redo functionality.
 - **`src/infra`**: The "Hands". Handles external systems:
     - **`midi/`**: RtMidi backend and MIDI file export/import.
-    - **`audio/`**: RtAudio backend and audio recording.
+    - **`audio/`**: ALSA/JACK backend for audio recording and playback.
     - **`video/`**: ffmpeg-based video generation.
     - **`settings/`**: Persistent configuration management.
 - **`src/view`**: The "Face". Pure QML-based UI, communicating with the application layer via models and services.
@@ -27,7 +27,7 @@ The project follows a layered architecture to ensure separation of concerns:
 - **Build System**: CMake with Ninja.
 - **Backend**:
   - **MIDI**: RtMidi.
-  - **Audio**: RtAudio / JACK.
+  - **Audio**: ALSA / JACK.
   - **File IO**: libsndfile, Qt XML.
 - **Testing**: CTest + Qt Test.
 

CHANGELOG

@@ -11,6 +11,8 @@ Bug fixes:
 
 Other:
 
+* Replace RtAudio with a custom ALSA backend
+
 2.1.0
 =====
 

CMakeLists.txt

@@ -46,8 +46,8 @@ find_package(PkgConfig REQUIRED)
 # Use pkg-config to find RtMidi
 pkg_check_modules(RTMIDI REQUIRED rtmidi)
 
-# Use pkg-config to find RtAudio
-pkg_check_modules(RTAUDIO REQUIRED rtaudio)
+# Use pkg-config to find ALSA
+pkg_check_modules(ALSA REQUIRED alsa)
 
 # Use pkg-config to find JACK
 if(ENABLE_JACK_SUPPORT)

README.md

@@ -6,7 +6,7 @@ Noteahead is a "simple" MIDI tracker and sequencer for Linux focusing on ease of
 
 Noteahead is designed to be especially a MIDI tracker, so it has/will have features that make MIDI sequencing as easy as possible.
 
-Noteahead is written in Qt/QML/C++20 on top of RtMidi back-end + RtAudio for the audio recorder. It builds with CMake and uses CTest + Qt Test framework for unit tests.
+Noteahead is written in Qt/QML/C++20 on top of RtMidi back-end + native ALSA/JACK for audio recording and playback. It builds with CMake and uses CTest + Qt Test framework for unit tests.
 
 <table>
   <tr><td colspan="3"><img src="/screenshots/1.8.0/1.png" width="100%"></td></tr>
@@ -197,7 +197,7 @@ Noteahead is currently being developed on Ubuntu 24.04 LTS and on Ubuntu 25.10 w
 
 Packages needed for building:
 
-    $ sudo apt install build-essential cmake pkg-config ninja-build qt6-base-dev qt6-declarative-dev qt6-tools-dev librtmidi-dev librtaudio-dev libsndfile-dev libjack-jackd2-dev
+    $ sudo apt install build-essential cmake pkg-config ninja-build qt6-base-dev qt6-declarative-dev qt6-tools-dev librtmidi-dev libasound2-dev libsndfile-dev libjack-jackd2-dev
 
 **Note**: As we are in the middle of the PipeWire transition, the Jack development files might not be needed.
 

io.github.juzzlin.Noteahead.yml

@@ -22,14 +22,6 @@ modules:
         sha256: ef7bcda27fee6936b651c29ebe9544c74959d0b1583b716ce80a1c6fea7617f0
     builddir: true
 
-  - name: rtaudio
-    buildsystem: cmake-ninja
-    sources:
-      - type: archive
-        url: https://github.com/thestk/rtaudio/archive/refs/tags/6.0.1.tar.gz
-        sha256: 7206c8b6cee43b474f43d64988fefaadfdcfc4264ed38d8de5f5d0e6ddb0a123
-    builddir: true
-
   - name: libsndfile
     buildsystem: cmake-ninja
     config-opts:

src/CMakeLists.txt

@@ -7,12 +7,11 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
 # These are needed only for the IDE
 set(HEADER_FILES
   application/application.hpp
-  application/instrument_request.hpp
-  application/command/note_edit_command.hpp
   application/command/automation_command.hpp
   application/command/composite_command.hpp
+  application/command/note_edit_command.hpp
   application/command/undo_stack.hpp
-  view/qml/Editor/line_number_renderer.hpp
+  application/instrument_request.hpp
   application/models/audio_settings_model.hpp
   application/models/column_settings_model.hpp
   application/models/event_selection_model.hpp
@@ -24,10 +23,9 @@ set(HEADER_FILES
   application/models/note_column_model_handler.hpp
   application/models/pitch_bend_automations_model.hpp
   application/models/recent_files_model.hpp
-  application/models/track_settings_model.hpp
   application/models/sampler/sampler_pad_model.hpp
+  application/models/track_settings_model.hpp
   application/note_converter.hpp
-  view/qml/Editor/note_column_renderer.hpp
   application/position.hpp
   application/service/application_service.hpp
   application/service/audio_service.hpp
@@ -58,9 +56,9 @@ set(HEADER_FILES
   common/constants.hpp
   common/utils.hpp
   common/waveform_generator.hpp
+  domain/arpeggiator.hpp
   domain/automation.hpp
   domain/automation_location.hpp
-  domain/arpeggiator.hpp
   domain/column.hpp
   domain/column_settings.hpp
   domain/devices/device.hpp
@@ -88,12 +86,17 @@ set(HEADER_FILES
   domain/side_chain_settings.hpp
   domain/song.hpp
   domain/track.hpp
+  infra/audio/async_audio_file_reader.hpp
+  infra/audio/async_audio_file_writer.hpp
   infra/audio/audio_engine.hpp
+  infra/audio/audio_player.hpp
   infra/audio/audio_recorder.hpp
   infra/audio/backend/audio_file_reader.hpp
   infra/audio/backend/sndfile_reader.hpp
+  infra/audio/implementation/alsa/audio_player_alsa.hpp
+  infra/audio/implementation/alsa/audio_recorder_alsa.hpp
+  infra/audio/implementation/jack/audio_player_jack.hpp
   infra/audio/implementation/jack/audio_recorder_jack.hpp
-  infra/audio/implementation/librtaudio/audio_recorder_rt_audio.hpp
   infra/audio/ring_buffer.hpp
   infra/midi/export/midi_exporter.hpp
   infra/midi/import/midi_importer.hpp
@@ -110,16 +113,17 @@ set(HEADER_FILES
   infra/video/default_animation.hpp
   infra/video/video_config.hpp
   infra/video/video_generator.hpp
+  view/qml/Editor/line_number_renderer.hpp
+  view/qml/Editor/note_column_renderer.hpp
 )
 
 set(SOURCE_FILES
   application/application.cpp
-  application/instrument_request.cpp
-  application/command/note_edit_command.cpp
   application/command/automation_command.cpp
   application/command/composite_command.cpp
+  application/command/note_edit_command.cpp
   application/command/undo_stack.cpp
-  view/qml/Editor/line_number_renderer.cpp
+  application/instrument_request.cpp
   application/models/audio_settings_model.cpp
   application/models/column_settings_model.cpp
   application/models/event_selection_model.cpp
@@ -131,11 +135,10 @@ set(SOURCE_FILES
   application/models/note_column_model_handler.cpp
   application/models/pitch_bend_automations_model.cpp
   application/models/recent_files_model.cpp
-  application/models/track_settings_model.cpp
   application/models/sampler/sampler_model.cpp
   application/models/sampler/sampler_pad_model.cpp
+  application/models/track_settings_model.cpp
   application/note_converter.cpp
-  view/qml/Editor/note_column_renderer.cpp
   application/service/application_service.cpp
   application/service/audio_service.cpp
   application/service/audio_worker.cpp
@@ -166,11 +169,13 @@ set(SOURCE_FILES
   common/constants.cpp
   common/utils.cpp
   common/waveform_generator.cpp
+  domain/arpeggiator.cpp
   domain/automation.cpp
   domain/automation_location.cpp
-  domain/arpeggiator.cpp
   domain/column.cpp
   domain/column_settings.cpp
+  domain/devices/device.cpp
+  domain/devices/sampler_device.cpp
   domain/event.cpp
   domain/event_data.cpp
   domain/instrument.cpp
@@ -192,16 +197,16 @@ set(SOURCE_FILES
   domain/play_order.cpp
   domain/song.cpp
   domain/track.cpp
-  domain/devices/device.cpp
-  domain/devices/sampler_device.cpp
+  infra/audio/async_audio_file_reader.cpp
+  infra/audio/async_audio_file_writer.cpp
   infra/audio/audio_engine.cpp
-  infra/audio/audio_recorder.cpp
   infra/audio/audio_player.cpp
+  infra/audio/audio_recorder.cpp
   infra/audio/backend/sndfile_reader.cpp
-  infra/audio/implementation/jack/audio_recorder_jack.cpp
+  infra/audio/implementation/alsa/audio_player_alsa.cpp
+  infra/audio/implementation/alsa/audio_recorder_alsa.cpp
   infra/audio/implementation/jack/audio_player_jack.cpp
-  infra/audio/implementation/librtaudio/audio_recorder_rt_audio.cpp
-  infra/audio/implementation/librtaudio/audio_player_rt_audio.cpp
+  infra/audio/implementation/jack/audio_recorder_jack.cpp
   infra/midi/export/midi_exporter.cpp
   infra/midi/import/midi_importer.cpp
   infra/midi/implementation/librtmidi/midi_in_rt_midi.cpp
@@ -217,6 +222,8 @@ set(SOURCE_FILES
   infra/video/default_animation.cpp
   infra/video/video_generator.cpp
   main.cpp
+  view/qml/Editor/line_number_renderer.cpp
+  view/qml/Editor/note_column_renderer.cpp
 )
 
 qt_add_executable(${BINARY_NAME} ${HEADER_FILES} ${SOURCE_FILES})
@@ -354,7 +361,7 @@ qt_add_qml_module(${BINARY_NAME}
 
 target_include_directories(${BINARY_NAME} PRIVATE contrib/SimpleLogger/src)
 target_include_directories(${BINARY_NAME} PRIVATE contrib/Argengine/src)
-target_include_directories(${BINARY_NAME} PRIVATE ${RTAUDIO_INCLUDE_DIRS})
+target_include_directories(${BINARY_NAME} PRIVATE ${ALSA_INCLUDE_DIRS})
 target_include_directories(${BINARY_NAME} PRIVATE ${SNDFILE_INCLUDE_DIRS})
 
 target_compile_definitions(${BINARY_NAME} PRIVATE $<$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>:QT_QML_DEBUG>)
@@ -365,7 +372,7 @@ if(ENABLE_MIDI_DEBUG)
   target_compile_definitions(${BINARY_NAME} PRIVATE ENABLE_MIDI_DEBUG)
 endif()
 
-target_link_libraries(${BINARY_NAME} PRIVATE Qt6::Core Qt6::Quick ${RTMIDI_LIBRARIES} ${RTAUDIO_LIBRARIES} ${SNDFILE_LIBRARIES} SimpleLogger_static Argengine_static)
+target_link_libraries(${BINARY_NAME} PRIVATE Qt6::Core Qt6::Quick ${RTMIDI_LIBRARIES} ${ALSA_LIBRARIES} ${SNDFILE_LIBRARIES} SimpleLogger_static Argengine_static)
 
 if(JACK_FOUND)
   target_include_directories(${BINARY_NAME} PRIVATE ${JACK_INCLUDE_DIRS})

src/application/service/audio_service.cpp

@@ -20,12 +20,11 @@
 #include "../../contrib/SimpleLogger/src/simple_logger.hpp"
 #include "../../infra/audio/implementation/jack/audio_recorder_jack.hpp"
 #include "../../infra/audio/implementation/jack/audio_player_jack.hpp"
-#include "../../infra/audio/implementation/librtaudio/audio_recorder_rt_audio.hpp"
-#include "../../infra/audio/implementation/librtaudio/audio_player_rt_audio.hpp"
+#include "../../infra/audio/implementation/alsa/audio_recorder_alsa.hpp"
+#include "../../infra/audio/implementation/alsa/audio_player_alsa.hpp"
 #include "audio_worker.hpp"
 #include "settings_service.hpp"
 
-#include <RtAudio.h>
 #include <sndfile.h>
 #include <QFile>
 #include <QTimer>
@@ -42,6 +41,9 @@ AudioService::AudioService(SettingsServiceS settingsService, JackServiceS jackSe
   , m_audioEngine { std::move(audioEngine) }
 {
     connect(m_settingsService.get(), &SettingsService::jackSyncEnabledChanged, this, &AudioService::reinitialize);
+    connect(m_settingsService.get(), &SettingsService::audioBufferSizeChanged, this, &AudioService::reinitialize);
+    connect(m_settingsService.get(), &SettingsService::audioInputDeviceIdChanged, this, &AudioService::reinitialize);
+    connect(m_settingsService.get(), &SettingsService::audioOutputDeviceIdChanged, this, &AudioService::reinitialize);
 
     if (autoInitialize) {
         reinitialize();
@@ -73,8 +75,8 @@ void AudioService::reinitialize()
         audioRecorder = std::make_unique<AudioRecorderJack>(m_jackService);
         audioPlayer = std::make_unique<AudioPlayerJack>(m_jackService);
     } else {
-        audioRecorder = std::make_unique<AudioRecorderRtAudio>(m_audioEngine, RtAudio::UNSPECIFIED);
-        audioPlayer = std::make_unique<AudioPlayerRtAudio>(m_audioEngine, RtAudio::UNSPECIFIED);
+        audioRecorder = std::make_unique<AudioRecorderAlsa>(m_audioEngine);
+        audioPlayer = std::make_unique<AudioPlayerAlsa>(m_audioEngine);
     }
 
     m_audioWorker = std::make_unique<AudioWorker>(std::move(audioRecorder), std::move(audioPlayer), m_audioEngine);

src/application/service/audio_worker.hpp

@@ -20,7 +20,6 @@
 #include <QTimer>
 #include <QVariantList>
 
-#include <RtAudio.h>
 #include <memory>
 
 namespace noteahead {