1 files changed, 472 insertions, 0 deletions
diff --git a/sys/wasapi/gstmmdeviceenumerator.cpp b/sys/wasapi/gstmmdeviceenumerator.cpp
new file mode 100644
index 000000000..1826b7fe1
--- /dev/null
+++ b/sys/wasapi/gstmmdeviceenumerator.cpp
@@ -0,0 +1,472 @@
+/* GStreamer
+ * Copyright (C) 2021 Seungha Yang <seungha@centricular.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstmmdeviceenumerator.h"
+
+#ifndef INITGUID
+#include <initguid.h>
+#endif
+
+/* *INDENT-OFF* */
+G_BEGIN_DECLS
+
+GST_DEBUG_CATEGORY_EXTERN (gst_wasapi_debug);
+#define GST_CAT_DEFAULT gst_wasapi_debug
+
+G_END_DECLS
+
+/* IMMNotificationClient implementation */
+class GstIMMNotificationClient : public IMMNotificationClient
+{
+public:
+  static HRESULT
+  CreateInstance (GstMMDeviceEnumerator * enumerator,
+      const GstMMNotificationClientCallbacks * callbacks,
+      gpointer user_data,
+      IMMNotificationClient ** client)
+  {
+    GstIMMNotificationClient *self;
+
+    self = new GstIMMNotificationClient ();
+
+    self->callbacks_ = *callbacks;
+    self->user_data_ = user_data;
+    g_weak_ref_set (&self->enumerator_, enumerator);
+
+    *client = (IMMNotificationClient *) self;
+
+    return S_OK;
+  }
+
+  /* IUnknown */
+  STDMETHODIMP
+  QueryInterface (REFIID riid, void ** object)
+  {
+    if (!object)
+      return E_POINTER;
+
+    if (riid == IID_IUnknown) {
+      *object = static_cast<IUnknown *> (this);
+    } else if (riid == __uuidof(IMMNotificationClient)) {
+      *object = static_cast<IMMNotificationClient *> (this);
+    } else {
+      *object = nullptr;
+      return E_NOINTERFACE;
+    }
+
+    AddRef ();
+
+    return S_OK;
+  }
+
+  STDMETHODIMP_ (ULONG)
+  AddRef (void)
+  {
+    GST_TRACE ("%p, %d", this, (guint) ref_count_);
+    return InterlockedIncrement (&ref_count_);
+  }
+
+  STDMETHODIMP_ (ULONG)
+  Release (void)
+  {
+    ULONG ref_count;
+
+    GST_TRACE ("%p, %d", this, (guint) ref_count_);
+    ref_count = InterlockedDecrement (&ref_count_);
+
+    if (ref_count == 0) {
+      GST_TRACE ("Delete instance %p", this);
+      delete this;
+    }
+
+    return ref_count;
+  }
+
+  /* IMMNotificationClient */
+  STDMETHODIMP
+  OnDeviceStateChanged (LPCWSTR device_id, DWORD new_state)
+  {
+    GstMMDeviceEnumerator *listener;
+    HRESULT hr;
+
+    if (!callbacks_.device_state_changed)
+      return S_OK;
+
+    listener = (GstMMDeviceEnumerator *) g_weak_ref_get (&enumerator_);
+    if (!listener)
+      return S_OK;
+
+    hr = callbacks_.device_state_changed (listener, device_id, new_state,
+        user_data_);
+    gst_object_unref (listener);
+
+    return hr;
+  }
+
+  STDMETHODIMP
+  OnDeviceAdded (LPCWSTR device_id)
+  {
+    GstMMDeviceEnumerator *listener;
+    HRESULT hr;
+
+    if (!callbacks_.device_added)
+      return S_OK;
+
+    listener = (GstMMDeviceEnumerator *) g_weak_ref_get (&enumerator_);
+    if (!listener)
+      return S_OK;
+
+    hr = callbacks_.device_added (listener, device_id, user_data_);
+    gst_object_unref (listener);
+
+    return hr;
+  }
+
+  STDMETHODIMP
+  OnDeviceRemoved (LPCWSTR device_id)
+  {
+    GstMMDeviceEnumerator *listener;
+    HRESULT hr;
+
+    if (!callbacks_.device_removed)
+      return S_OK;
+
+    listener = (GstMMDeviceEnumerator *) g_weak_ref_get (&enumerator_);
+    if (!listener)
+      return S_OK;
+
+    hr = callbacks_.device_removed (listener, device_id, user_data_);
+    gst_object_unref (listener);
+
+    return hr;
+  }
+
+  STDMETHODIMP
+  OnDefaultDeviceChanged (EDataFlow flow, ERole role, LPCWSTR default_device_id)
+  {
+    GstMMDeviceEnumerator *listener;
+    HRESULT hr;
+
+    if (!callbacks_.default_device_changed)
+      return S_OK;
+
+    listener = (GstMMDeviceEnumerator *) g_weak_ref_get (&enumerator_);
+    if (!listener)
+      return S_OK;
+
+    hr = callbacks_.default_device_changed (listener,
+        flow, role, default_device_id, user_data_);
+    gst_object_unref (listener);
+
+    return hr;
+  }
+
+  STDMETHODIMP
+  OnPropertyValueChanged (LPCWSTR device_id, const PROPERTYKEY key)
+  {
+    GstMMDeviceEnumerator *listener;
+    HRESULT hr;
+
+    if (!callbacks_.property_value_changed)
+      return S_OK;
+
+    listener = (GstMMDeviceEnumerator *) g_weak_ref_get (&enumerator_);
+    if (!device_id)
+      return S_OK;
+
+    hr = callbacks_.property_value_changed (listener,
+        device_id, key, user_data_);
+    gst_object_unref (listener);
+
+    return hr;
+  }
+
+private:
+  GstIMMNotificationClient ()
+    : ref_count_ (1)
+  {
+    g_weak_ref_init (&enumerator_, nullptr);
+  }
+
+  virtual ~GstIMMNotificationClient ()
+  {
+    g_weak_ref_clear (&enumerator_);
+  }
+
+private:
+  ULONG ref_count_;
+  GstMMNotificationClientCallbacks callbacks_;
+  gpointer user_data_;
+  GWeakRef enumerator_;
+};
+/* *INDENT-ON* */
+
+struct _GstMMDeviceEnumerator
+{
+  GstObject parent;
+
+  IMMDeviceEnumerator *handle;
+  IMMNotificationClient *client;
+
+  GMutex lock;
+  GCond cond;
+
+  GThread *thread;
+  GMainContext *context;
+  GMainLoop *loop;
+
+  gboolean running;
+};
+
+static void gst_mm_device_enumerator_constructed (GObject * object);
+static void gst_mm_device_enumerator_finalize (GObject * object);
+
+static gpointer
+gst_mm_device_enumerator_thread_func (GstMMDeviceEnumerator * self);
+
+#define gst_mm_device_enumerator_parent_class parent_class
+G_DEFINE_TYPE (GstMMDeviceEnumerator,
+    gst_mm_device_enumerator, GST_TYPE_OBJECT);
+
+static void
+gst_mm_device_enumerator_class_init (GstMMDeviceEnumeratorClass * klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+  gobject_class->constructed = gst_mm_device_enumerator_constructed;
+  gobject_class->finalize = gst_mm_device_enumerator_finalize;
+}
+
+static void
+gst_mm_device_enumerator_init (GstMMDeviceEnumerator * self)
+{
+  g_mutex_init (&self->lock);
+  g_cond_init (&self->cond);
+  self->context = g_main_context_new ();
+  self->loop = g_main_loop_new (self->context, FALSE);
+}
+
+static void
+gst_mm_device_enumerator_constructed (GObject * object)
+{
+  GstMMDeviceEnumerator *self = GST_MM_DEVICE_ENUMERATOR (object);
+
+  g_mutex_lock (&self->lock);
+  self->thread = g_thread_new ("GstMMDeviceEnumerator",
+      (GThreadFunc) gst_mm_device_enumerator_thread_func, self);
+  while (!g_main_loop_is_running (self->loop))
+    g_cond_wait (&self->cond, &self->lock);
+  g_mutex_unlock (&self->lock);
+}
+
+static void
+gst_mm_device_enumerator_finalize (GObject * object)
+{
+  GstMMDeviceEnumerator *self = GST_MM_DEVICE_ENUMERATOR (object);
+
+  g_main_loop_quit (self->loop);
+  g_thread_join (self->thread);
+  g_main_loop_unref (self->loop);
+  g_main_context_unref (self->context);
+
+  g_mutex_clear (&self->lock);
+  g_cond_clear (&self->cond);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static gboolean
+loop_running_cb (GstMMDeviceEnumerator * self)
+{
+  g_mutex_lock (&self->lock);
+  g_cond_signal (&self->cond);
+  g_mutex_unlock (&self->lock);
+
+  return G_SOURCE_REMOVE;
+}
+
+static gpointer
+gst_mm_device_enumerator_thread_func (GstMMDeviceEnumerator * self)
+{
+  GSource *idle_source;
+  IMMDeviceEnumerator *enumerator = nullptr;
+  HRESULT hr;
+
+  CoInitializeEx (NULL, COINIT_MULTITHREADED);
+  g_main_context_push_thread_default (self->context);
+
+  idle_source = g_idle_source_new ();
+  g_source_set_callback (idle_source,
+      (GSourceFunc) loop_running_cb, self, nullptr);
+  g_source_attach (idle_source, self->context);
+  g_source_unref (idle_source);
+
+  hr = CoCreateInstance (__uuidof (MMDeviceEnumerator),
+      nullptr, CLSCTX_ALL, IID_PPV_ARGS (&enumerator));
+  if (FAILED (hr)) {
+    GST_ERROR_OBJECT (self, "Failed to create IMMDeviceEnumerator instance");
+    goto run_loop;
+  }
+
+  self->handle = enumerator;
+
+run_loop:
+  GST_INFO_OBJECT (self, "Starting loop");
+  g_main_loop_run (self->loop);
+  GST_INFO_OBJECT (self, "Stopped loop");
+
+  if (self->client && self->handle) {
+    self->handle->UnregisterEndpointNotificationCallback (self->client);
+
+    self->client->Release ();
+  }
+
+  if (self->handle)
+    self->handle->Release ();
+
+  g_main_context_pop_thread_default (self->context);
+  CoUninitialize ();
+
+  return nullptr;
+}
+
+GstMMDeviceEnumerator *
+gst_mm_device_enumerator_new (void)
+{
+  GstMMDeviceEnumerator *self;
+
+  self = (GstMMDeviceEnumerator *) g_object_new (GST_TYPE_MM_DEVICE_ENUMERATOR,
+      nullptr);
+
+  if (!self->handle) {
+    gst_object_unref (self);
+    return nullptr;
+  }
+
+  gst_object_ref_sink (self);
+
+  return self;
+}
+
+IMMDeviceEnumerator *
+gst_mm_device_enumerator_get_handle (GstMMDeviceEnumerator * enumerator)
+{
+  g_return_val_if_fail (GST_IS_MM_DEVICE_ENUMERATOR (enumerator), nullptr);
+
+  return enumerator->handle;
+}
+
+typedef struct
+{
+  GstMMDeviceEnumerator *self;
+  GstMMNotificationClientCallbacks *callbacks;
+  gpointer user_data;
+
+  gboolean handled;
+  GMutex lock;
+  GCond cond;
+
+  gboolean ret;
+} SetNotificationCallbackData;
+
+static gboolean
+set_notification_callback (SetNotificationCallbackData * data)
+{
+  GstMMDeviceEnumerator *self = data->self;
+  HRESULT hr;
+
+  g_mutex_lock (&data->lock);
+  g_mutex_lock (&self->lock);
+
+  data->ret = TRUE;
+
+  if (self->client) {
+    self->handle->UnregisterEndpointNotificationCallback (self->client);
+    self->client->Release ();
+    self->client = nullptr;
+  }
+
+  if (data->callbacks) {
+    IMMNotificationClient *client;
+
+    hr = GstIMMNotificationClient::CreateInstance (self, data->callbacks,
+        data->user_data, &client);
+    if (FAILED (hr)) {
+      GST_ERROR_OBJECT (self,
+          "Failed to create IMMNotificationClient instance");
+      data->ret = FALSE;
+      goto out;
+    }
+
+    hr = self->handle->RegisterEndpointNotificationCallback (client);
+    if (FAILED (hr)) {
+      GST_ERROR_OBJECT (self, "Failed to register callback");
+      client->Release ();
+      data->ret = FALSE;
+      goto out;
+    }
+
+    self->client = client;
+  }
+
+out:
+  data->handled = TRUE;
+  g_cond_signal (&data->cond);
+  g_mutex_unlock (&self->lock);
+  g_mutex_unlock (&data->lock);
+
+  return G_SOURCE_REMOVE;
+}
+
+gboolean
+gst_mm_device_enumerator_set_notification_callback (GstMMDeviceEnumerator *
+    enumerator, GstMMNotificationClientCallbacks * callbacks,
+    gpointer user_data)
+{
+  SetNotificationCallbackData data;
+  gboolean ret;
+
+  g_return_val_if_fail (GST_IS_MM_DEVICE_ENUMERATOR (enumerator), FALSE);
+
+  data.self = enumerator;
+  data.callbacks = callbacks;
+  data.user_data = user_data;
+  data.handled = FALSE;
+
+  g_mutex_init (&data.lock);
+  g_cond_init (&data.cond);
+
+  g_main_context_invoke (enumerator->context,
+      (GSourceFunc) set_notification_callback, &data);
+  g_mutex_lock (&data.lock);
+  while (!data.handled)
+    g_cond_wait (&data.cond, &data.lock);
+  g_mutex_unlock (&data.lock);
+
+  ret = data.ret;
+
+  g_mutex_clear (&data.lock);
+  g_cond_clear (&data.cond);
+
+  return ret;
+}