Decouple audio capture from projectM wrapper + GHA fixes

src/AudioCapture.cpp

@@ -19,8 +19,6 @@ void AudioCapture::initialize(Poco::Util::Application& app)
 {
     _config = app.config().createView("audio");
 
-    auto& projectMWrapper = app.getSubsystem<ProjectMWrapper>();
-
     if (!_impl)
     {
         _impl = new AudioCaptureImpl;
@@ -31,7 +29,7 @@ void AudioCapture::initialize(Poco::Util::Application& app)
 
     PrintDeviceList(deviceList);
 
-    _impl->StartRecording(projectMWrapper.ProjectM(), audioDeviceIndex);
+    _impl->StartRecording(audioDeviceIndex);
 }
 
 void AudioCapture::uninitialize()

src/AudioCaptureImpl_CoreAudioTap.h

@@ -40,10 +40,9 @@ class CoreAudioTapCapture
 
     /**
      * @brief Starts capturing system audio and forwarding it to projectM.
-     * @param projectMHandle projectM instance handle that will receive the captured data.
      * @param audioDeviceIndex Ignored in v1 (single system-audio source).
      */
-    void StartRecording(projectm* projectMHandle, int audioDeviceIndex);
+    void StartRecording(int audioDeviceIndex);
 
     /**
      * @brief Stops capturing and tears down the tap and aggregate device.

src/AudioCaptureImpl_CoreAudioTap.mm

@@ -1,6 +1,8 @@
 #include "AudioCaptureImpl_CoreAudioTap.h"
 
-#include <projectM-4/projectM.h>
+#include "notifications/AudioDataAvailableNotification.h"
+
+#include <Poco/NotificationCenter.h>
 
 #import <CoreAudio/CoreAudio.h>
 #import <Foundation/Foundation.h>
@@ -26,9 +28,8 @@
     return {{-1, _systemAudioDeviceName}};
 }
 
-void CoreAudioTapCapture::StartRecording(projectm* projectMHandle, int audioDeviceIndex)
+void CoreAudioTapCapture::StartRecording(int audioDeviceIndex)
 {
-    _projectMHandle = projectMHandle;
     _currentAudioDeviceIndex = -1; // Only one source in v1.
 
     if (StartTap())
@@ -188,15 +189,14 @@
             // 4. Install the IO proc. Runs on Core Audio's realtime thread; keep it allocation-
             //    and lock-free. Core Audio delivers deinterleaved float buffers (one buffer per
             //    channel) for tap aggregates, so forward the first buffer's frames to projectM.
-            projectm* handle = _projectMHandle;
             uint32_t channels = _channels;
 
             status = AudioDeviceCreateIOProcIDWithBlock(
                 &_ioProcID, _aggregateDeviceID, nullptr,
                 ^(const AudioTimeStamp* /*inNow*/, const AudioBufferList* inInputData,
                   const AudioTimeStamp* /*inInputTime*/, AudioBufferList* /*outOutputData*/,
                   const AudioTimeStamp* /*inOutputTime*/) {
-                  if (handle == nullptr || inInputData == nullptr || inInputData->mNumberBuffers == 0)
+                  if (inInputData == nullptr || inInputData->mNumberBuffers == 0)
                   {
                       return;
                   }
@@ -210,10 +210,10 @@
                   auto* samples = static_cast<float*>(buffer.mData);
                   // mNumberChannels reflects the interleaving of this buffer.
                   uint32_t bufferChannels = buffer.mNumberChannels > 0 ? buffer.mNumberChannels : channels;
-                  unsigned int frameCount = buffer.mDataByteSize / sizeof(float) / bufferChannels;
+                  unsigned int sampleCount = buffer.mDataByteSize / sizeof(float);
 
-                  projectm_pcm_add_float(handle, samples, frameCount,
-                                         static_cast<projectm_channels>(bufferChannels));
+                  Poco::NotificationCenter::defaultCenter().postNotification(
+                      new AudioDataAvailableNotification(bufferChannels, samples, sampleCount));
                 });
 
             if (status != noErr || _ioProcID == nullptr)

src/AudioCaptureImpl_SDL.cpp

@@ -1,11 +1,11 @@
 #include "AudioCaptureImpl_SDL.h"
 
-#include <Poco/Util/Application.h>
+#include "notifications/AudioDataAvailableNotification.h"
 
-#include <projectM-4/projectM.h>
+#include <Poco/NotificationCenter.h>
+#include <Poco/Util/Application.h>
 
 AudioCaptureImpl::AudioCaptureImpl()
-    : _requestedSampleCount(projectm_pcm_get_max_samples())
 {
     auto targetFps = Poco::Util::Application::instance().config().getUInt("projectM.fps", 60);
     if (targetFps > 0)
@@ -50,9 +50,8 @@ std::map<int, std::string> AudioCaptureImpl::AudioDeviceList()
     return deviceList;
 }
 
-void AudioCaptureImpl::StartRecording(projectm* projectMHandle, int audioDeviceIndex)
+void AudioCaptureImpl::StartRecording(int audioDeviceIndex)
 {
-    _projectMHandle = projectMHandle;
     _currentAudioDeviceIndex = audioDeviceIndex;
 
     poco_debug_f1(_logger, "Using SDL audio driver \"%s\".", std::string(SDL_GetCurrentAudioDriver()));
@@ -84,7 +83,7 @@ void AudioCaptureImpl::NextAudioDevice()
     // Will wrap around to default capture device (-1).
     int nextAudioDeviceId = ((_currentAudioDeviceIndex + 2) % (SDL_GetNumAudioDevices(true) + 1)) - 1;
 
-    StartRecording(_projectMHandle, nextAudioDeviceId);
+    StartRecording(nextAudioDeviceId);
 }
 
 void AudioCaptureImpl::AudioDeviceIndex(int index)
@@ -93,7 +92,7 @@ void AudioCaptureImpl::AudioDeviceIndex(int index)
     {
         StopRecording();
         _currentAudioDeviceIndex = index;
-        StartRecording(_projectMHandle, index);
+        StartRecording(index);
     }
 }
 
@@ -153,10 +152,18 @@ bool AudioCaptureImpl::OpenAudioDevice()
 void AudioCaptureImpl::AudioInputCallback(void* userData, unsigned char* stream, int len)
 {
     poco_assert_dbg(userData);
+
+    if (len < sizeof(float))
+    {
+        return;
+    }
+
     auto instance = reinterpret_cast<AudioCaptureImpl*>(userData);
 
-    unsigned int samples = len / sizeof(float) / instance->_channels;
+    unsigned int samples = len / sizeof(float);
 
-    projectm_pcm_add_float(instance->_projectMHandle, reinterpret_cast<float*>(stream), samples,
-                           static_cast<projectm_channels>(instance->_channels));
+    Poco::NotificationCenter::defaultCenter().postNotification(
+        new AudioDataAvailableNotification(instance->_channels,
+                                           reinterpret_cast<float*>(stream),
+                                           samples));
 }

src/AudioCaptureImpl_SDL.h

@@ -5,7 +5,6 @@
 #include <Poco/Logger.h>
 
 #include <string>
-#include <vector>
 
 class projectm;
 
@@ -29,11 +28,10 @@ class AudioCaptureImpl
 
     /**
      * @brief Starts audio capturing with the first available device.
-     * @param projectMHandle projectM instance handle that will receive the captured data.
      * @param audioDeviceIndex The initial audio device ID to capture from. Use -1 to select the implementation's
      *                      default device.
      */
-    void StartRecording(projectm* projectMHandle, int audioDeviceIndex);
+    void StartRecording(int audioDeviceIndex);
 
     /**
      * @brief Stops audio recording.
@@ -66,9 +64,7 @@ class AudioCaptureImpl
     /**
      * @brief Asks the capture client to fill projectM's audio buffer for the next frame.
      *
-     * As of now, SDL uses async callbacks to directly fill projectM's audio buffer.
-     *
-     * @todo Store audio samples internally and push them to projectM when requested.
+     * SDL uses async callbacks to directly fill the staging audio buffer(s) as soon as new data is available.
      */
     void FillBuffer(){};
 
@@ -90,7 +86,6 @@ class AudioCaptureImpl
      */
     static void AudioInputCallback(void* userData, unsigned char* stream, int len);
 
-    projectm* _projectMHandle{nullptr}; //!< Handle if the projectM instance that will receive the audio data.
     int32_t _currentAudioDeviceIndex{-1}; //!< Currently selected audio device index.
     SDL_AudioDeviceID _currentAudioDeviceID{0}; //!< Device ID of the currently opened audio device.
     uint32_t _channels{2};

src/AudioCaptureImpl_WASAPI.cpp

@@ -1,9 +1,10 @@
 #include "AudioCaptureImpl_WASAPI.h"
 
-#include <projectM-4/projectM.h>
+#include "notifications/AudioDataAvailableNotification.h"
 
 #include <Poco/UnicodeConverter.h>
 
+#include <Poco/NotificationCenter.h>
 #include <functiondiscoverykeys_devpkey.h>
 #include <mmdeviceapi.h>
 #include <objbase.h>
@@ -42,9 +43,8 @@ std::map<int, std::string> AudioCaptureImpl::AudioDeviceList()
     return deviceList;
 }
 
-void AudioCaptureImpl::StartRecording(projectm* projectMHandle, int audioDeviceIndex)
+void AudioCaptureImpl::StartRecording(int audioDeviceIndex)
 {
-    _projectMHandle = projectMHandle;
     _currentAudioDeviceIndex = audioDeviceIndex;
 
     _isCapturing = true;
@@ -74,7 +74,7 @@ void AudioCaptureImpl::NextAudioDevice()
     // Will wrap around to loopback capture device (-1).
     int nextAudioDeviceId = ((_currentAudioDeviceIndex + 2) % (static_cast<int>(captureDevices.size()) + 1)) - 1;
 
-    StartRecording(_projectMHandle, nextAudioDeviceId);
+    StartRecording(nextAudioDeviceId);
 }
 
 void AudioCaptureImpl::AudioDeviceIndex(int index)
@@ -87,7 +87,7 @@ void AudioCaptureImpl::AudioDeviceIndex(int index)
     {
         _currentAudioDeviceIndex = index;
         StopRecording();
-        StartRecording(_projectMHandle, index);
+        StartRecording(index);
     }
 }
 
@@ -447,7 +447,10 @@ void AudioCaptureImpl::CaptureThread()
 
                 if (framesAvailable > 0 && data != nullptr)
                 {
-                    projectm_pcm_add_float(_projectMHandle, reinterpret_cast<float*>(data), framesAvailable, static_cast<projectm_channels>(_channels));
+                    Poco::NotificationCenter::defaultCenter().postNotification(
+                        new AudioDataAvailableNotification(_channels,
+                                                           reinterpret_cast<float*>(data),
+                                                           framesAvailable * _channels));
                 }
 
                 _audioCaptureClient->ReleaseBuffer(framesAvailable);

src/AudioCaptureImpl_WASAPI.h

@@ -45,11 +45,10 @@ class AudioCaptureImpl : public IMMNotificationClient
 
     /**
      * @brief Starts audio capturing with the first available device.
-     * @param projectMHandle projectM instance handle that will receive the captured data.
      * @param audioDeviceIndex The initial audio device ID to capture from. Use -1 to select the implementation's
      *                      default device.
      */
-    void StartRecording(projectm* projectMHandle, int audioDeviceIndex);
+    void StartRecording(int audioDeviceIndex);
 
     /**
      * @brief Stops audio recording.

src/AudioCaptureImpl_macOS.h

@@ -30,7 +30,7 @@ class AudioCaptureImpl
 
     std::map<int, std::string> AudioDeviceList();
 
-    void StartRecording(projectm* projectMHandle, int audioDeviceIndex);
+    void StartRecording(int audioDeviceIndex);
 
     void StopRecording();
 

src/AudioCaptureImpl_macOS.mm

@@ -42,14 +42,14 @@
     return _sdl->AudioDeviceList();
 }
 
-void AudioCaptureImpl::StartRecording(projectm* projectMHandle, int audioDeviceIndex)
+void AudioCaptureImpl::StartRecording(int audioDeviceIndex)
 {
     if (_tap)
     {
-        _tap->StartRecording(projectMHandle, audioDeviceIndex);
+        _tap->StartRecording(audioDeviceIndex);
         return;
     }
-    _sdl->StartRecording(projectMHandle, audioDeviceIndex);
+    _sdl->StartRecording(audioDeviceIndex);
 }
 
 void AudioCaptureImpl::StopRecording()

src/ProjectMWrapper.cpp

@@ -108,6 +108,7 @@ void ProjectMWrapper::initialize(Poco::Util::Application& app)
     }
 
     Poco::NotificationCenter::defaultCenter().addObserver(_playbackControlNotificationObserver);
+    Poco::NotificationCenter::defaultCenter().addObserver(_audioDataAvailableNotificationObserver);
 
     // Observe user configuration changes (set via the settings window)
     _userConfig->propertyChanged += Poco::delegate(this, &ProjectMWrapper::OnConfigurationPropertyChanged);
@@ -119,6 +120,7 @@ void ProjectMWrapper::uninitialize()
     _userConfig->propertyRemoved -= Poco::delegate(this, &ProjectMWrapper::OnConfigurationPropertyRemoved);
     _userConfig->propertyChanged -= Poco::delegate(this, &ProjectMWrapper::OnConfigurationPropertyChanged);
     Poco::NotificationCenter::defaultCenter().removeObserver(_playbackControlNotificationObserver);
+    Poco::NotificationCenter::defaultCenter().removeObserver(_audioDataAvailableNotificationObserver);
 
     if (_projectM)
     {
@@ -153,7 +155,7 @@ void ProjectMWrapper::UpdateRealFPS(float fps)
     projectm_set_fps(_projectM, static_cast<uint32_t>(std::round(fps)));
 }
 
-void ProjectMWrapper::RenderFrame() const
+void ProjectMWrapper::RenderFrame()
 {
     glClearColor(0.0, 0.0, 0.0, 0.0);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
@@ -167,6 +169,16 @@ void ProjectMWrapper::RenderFrame() const
         projectm_set_mesh_size(_projectM, _projectMConfigView->getInt("meshX", 220), _projectMConfigView->getInt("meshY", 125));
     }
 
+    // Add new audio data to the instance from the staging buffer
+    {
+        Poco::ScopedLock lock(_audioBufferMutex);
+        if (!_audioStagingBuffer.empty())
+        {
+            projectm_pcm_add_float(_projectM, _audioStagingBuffer.data(), _audioStagingBuffer.size() / _audioChannels, static_cast<projectm_channels>(_audioChannels));
+            _audioStagingBuffer.clear();
+        }
+    }
+
     projectm_opengl_render_frame(_projectM);
 }
 
@@ -263,6 +275,20 @@ void ProjectMWrapper::PlaybackControlNotificationHandler(const Poco::AutoPtr<Pla
     }
 }
 
+void ProjectMWrapper::AudioDataAvailableNotificationHandler(const Poco::AutoPtr<AudioDataAvailableNotification>& notification)
+{
+    Poco::ScopedLock lock(_audioBufferMutex);
+
+    // Clear existing buffer data if channel count differs, e.g. if audio device has changed
+    if (_audioChannels != notification->Channels())
+    {
+        _audioChannels = notification->Channels();
+        _audioStagingBuffer.clear();
+    }
+
+    std::copy(notification->Samples().cbegin(), notification->Samples().cend(), std::back_inserter(_audioStagingBuffer));
+}
+
 std::vector<std::string> ProjectMWrapper::GetPathListWithDefault(const std::string& baseKey, const std::string& defaultPath)
 {
     using Poco::Util::AbstractConfiguration;

src/ProjectMWrapper.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "notifications/AudioDataAvailableNotification.h"
 #include "notifications/PlaybackControlNotification.h"
 
 #include <projectM-4/projectM.h>
@@ -37,7 +38,7 @@ class ProjectMWrapper : public Poco::Util::Subsystem
     /**
      * Renders a single projectM frame.
      */
-    void RenderFrame() const;
+    void RenderFrame();
 
     /**
      * @brief Returns the targeted FPS value.
@@ -91,6 +92,8 @@ class ProjectMWrapper : public Poco::Util::Subsystem
 
     void PlaybackControlNotificationHandler(const Poco::AutoPtr<PlaybackControlNotification>& notification);
 
+    void AudioDataAvailableNotificationHandler(const Poco::AutoPtr<AudioDataAvailableNotification>& notification);
+
     std::vector<std::string> GetPathListWithDefault(const std::string& baseKey, const std::string& defaultPath);
 
     /**
@@ -111,7 +114,12 @@ class ProjectMWrapper : public Poco::Util::Subsystem
     projectm_handle _projectM{nullptr}; //!< Pointer to the projectM instance used by the application.
     projectm_playlist_handle _playlist{nullptr}; //!< Pointer to the projectM playlist manager instance.
 
+    uint32_t _audioChannels{0}; //!< Number of audio channels of the current capture device.
+    std::vector<float> _audioStagingBuffer; //!< Buffer which receives audio data from the capture implementation.
+    mutable Poco::Mutex _audioBufferMutex; //!< Mutex protecting access to the audio staging buffer.
+
     Poco::NObserver<ProjectMWrapper, PlaybackControlNotification> _playbackControlNotificationObserver{*this, &ProjectMWrapper::PlaybackControlNotificationHandler};
+    Poco::NObserver<ProjectMWrapper, AudioDataAvailableNotification> _audioDataAvailableNotificationObserver{*this, &ProjectMWrapper::AudioDataAvailableNotificationHandler};
 
     Poco::Logger& _logger{Poco::Logger::get("SDLRenderingWindow")}; //!< The class logger.
 };