✨ Added InputStream

CMakeLists.txt

@@ -4,7 +4,7 @@ set(WARNINGS_AS_ERRORS_FOR_RTAUDIOWRAPPER OFF CACHE BOOL "ON iff you want to tre
 
 add_library(RtAudioWrapper)
 add_library(RtAudioWrapper::RtAudioWrapper ALIAS RtAudioWrapper)
-target_compile_features(RtAudioWrapper PRIVATE cxx_std_11)
+target_compile_features(RtAudioWrapper PRIVATE cxx_std_20)
 
 # ---Add source files---
 if(WARNINGS_AS_ERRORS_FOR_RTAUDIOWRAPPER)

include/RtAudioWrapper/RtAudioWrapper.hpp

@@ -1,3 +1,4 @@
 #pragma once
 
-#include "../../src/Player.hpp"
+#include "../../src/InputStream.hpp"
+#include "../../src/Player.hpp"

src/InputStream.cpp

@@ -0,0 +1,48 @@
+#include "InputStream.hpp"
+
+namespace RtAudioW {
+
+InputStream::InputStream(AudioInputCallback callback)
+    : _callback{std::move(callback)}
+{
+    set_device(_backend.getDefaultInputDevice());
+}
+
+auto InputStream::device_ids() const -> std::vector<unsigned int>
+{
+    auto ids = _backend.getDeviceIds();
+    // Keep only the input devices
+    std::erase_if(ids, [&](unsigned int id) {
+        auto const info = _backend.getDeviceInfo(id);
+        return info.inputChannels == 0;
+    });
+    return ids;
+}
+
+auto InputStream::device_info(unsigned int device_id) const -> RtAudio::DeviceInfo
+{
+    return _backend.getDeviceInfo(device_id);
+}
+
+auto audio_input_callback(void* /* output_buffer */, void* input_buffer, unsigned int frames_count, double /* stream_time */, RtAudioStreamStatus /* status */, void* user_data) -> int
+{
+    static_cast<InputStream*>(user_data)->_callback(std::span{static_cast<float*>(input_buffer), frames_count});
+    return 0;
+}
+
+void InputStream::set_device(unsigned int device_id)
+{
+    if (_backend.isStreamOpen())
+        _backend.closeStream();
+
+    auto const                info = _backend.getDeviceInfo(device_id);
+    RtAudio::StreamParameters params;
+    params.deviceId  = device_id;
+    params.nChannels = 1;
+    unsigned int nb_frames{512}; // TODO(Audio) Allow users to customize this?
+    _backend.openStream(nullptr, &params, RTAUDIO_FLOAT32, info.preferredSampleRate, &nb_frames, &audio_input_callback, this);
+    _backend.startStream();
+    _current_input_device_name = info.name;
+}
+
+} // namespace RtAudioW

src/InputStream.hpp

@@ -0,0 +1,39 @@
+#pragma once
+#include <span>
+#include "rtaudio/RtAudio.h"
+
+namespace RtAudioW {
+
+/// Receives a buffer containing audio samples.
+/// There is always 1 channel in the input buffer.
+using AudioInputCallback = std::function<void(std::span<float>)>;
+
+class InputStream {
+public:
+    explicit InputStream(AudioInputCallback);
+    ~InputStream()                                         = default;
+    InputStream(InputStream const&)                        = delete; //
+    auto operator=(InputStream const&) -> InputStream&     = delete; // Can't copy nor move
+    InputStream(InputStream&&) noexcept                    = delete; // because we pass the address of this object to the audio callback.
+    auto operator=(InputStream&&) noexcept -> InputStream& = delete; //
+
+    /// Returns the list of all the ids of input devices.
+    auto device_ids() const -> std::vector<unsigned int>;
+    /// Returns all the info about a given device.
+    auto device_info(unsigned int device_id) const -> RtAudio::DeviceInfo;
+    ///
+    auto current_device_name() const -> std::string const& { return _current_input_device_name; }
+    /// Sets the device to use.
+    /// By default, when an InputStream is created it uses the default input device selected by the OS.
+    void set_device(unsigned int device_id);
+
+private:
+    friend auto audio_input_callback(void* output_buffer, void* input_buffer, unsigned int frames_count, double stream_time, RtAudioStreamStatus status, void* user_data) -> int;
+
+private:
+    mutable RtAudio    _backend{};
+    AudioInputCallback _callback{};
+    std::string        _current_input_device_name{};
+};
+
+} // namespace RtAudioW

tests/CMakeLists.txt

@@ -3,7 +3,7 @@ project(RtAudioWrapper-tests)
 
 # ---Create executable---
 add_executable(${PROJECT_NAME} tests.cpp)
-target_compile_features(${PROJECT_NAME} PRIVATE cxx_std_11)
+target_compile_features(${PROJECT_NAME} PRIVATE cxx_std_20)
 
 # ---Include our library---
 add_subdirectory(.. ${CMAKE_CURRENT_SOURCE_DIR}/build/RtAudioWrapper)