wasapi2: Add device provider implementation

Similar to device provider implementation of wasapi plugin,
this implementation supports only static probing.
But we can implement runtime device add/remove/update
monitoring using DeviceWatcher interface later.

See https://docs.microsoft.com/en-us/uwp/api/windows.devices.enumeration.devicewatcher

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1264>

4 files changed, 287 insertions, 0 deletions

diff --git a/sys/wasapi2/gstwasapi2device.c b/sys/wasapi2/gstwasapi2device.c
new file mode 100644
index 000000000..ac51126ca
--- /dev/null
+++ b/sys/wasapi2/gstwasapi2device.c
@@ -0,0 +1,245 @@
+/* GStreamer
+ * Copyright (C) 2018 Nirbheek Chauhan <nirbheek@centricular.com>
+ * Copyright (C) 2020 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 "gstwasapi2device.h"
+#include "gstwasapi2client.h"
+
+GST_DEBUG_CATEGORY_EXTERN (gst_wasapi2_debug);
+#define GST_CAT_DEFAULT gst_wasapi2_debug
+
+enum
+{
+  PROP_0,
+  PROP_DEVICE,
+};
+
+struct _GstWasapi2Device
+{
+  GstDevice parent;
+
+  gchar *device_id;
+  const gchar *factory_name;
+};
+
+G_DEFINE_TYPE (GstWasapi2Device, gst_wasapi2_device, GST_TYPE_DEVICE);
+
+static void gst_wasapi2_device_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec);
+static void gst_wasapi2_device_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec);
+static void gst_wasapi2_device_finalize (GObject * object);
+static GstElement *gst_wasapi2_device_create_element (GstDevice * device,
+    const gchar * name);
+
+static void
+gst_wasapi2_device_class_init (GstWasapi2DeviceClass * klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  GstDeviceClass *dev_class = GST_DEVICE_CLASS (klass);
+
+  dev_class->create_element = gst_wasapi2_device_create_element;
+
+  gobject_class->get_property = gst_wasapi2_device_get_property;
+  gobject_class->set_property = gst_wasapi2_device_set_property;
+  gobject_class->finalize = gst_wasapi2_device_finalize;
+
+  g_object_class_install_property (gobject_class, PROP_DEVICE,
+      g_param_spec_string ("device", "Device",
+          "WASAPI playback device as a GUID string", NULL,
+          G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));
+}
+
+static void
+gst_wasapi2_device_init (GstWasapi2Device * self)
+{
+}
+
+static void
+gst_wasapi2_device_finalize (GObject * object)
+{
+  GstWasapi2Device *self = GST_WASAPI2_DEVICE (object);
+
+  g_free (self->device_id);
+
+  G_OBJECT_CLASS (gst_wasapi2_device_parent_class)->finalize (object);
+}
+
+static GstElement *
+gst_wasapi2_device_create_element (GstDevice * device, const gchar * name)
+{
+  GstWasapi2Device *self = GST_WASAPI2_DEVICE (device);
+  GstElement *elem;
+
+  elem = gst_element_factory_make (self->factory_name, name);
+
+  g_object_set (elem, "device", self->device_id, NULL);
+
+  return elem;
+}
+
+static void
+gst_wasapi2_device_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstWasapi2Device *self = GST_WASAPI2_DEVICE (object);
+
+  switch (prop_id) {
+    case PROP_DEVICE:
+      g_value_set_string (value, self->device_id);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_wasapi2_device_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstWasapi2Device *self = GST_WASAPI2_DEVICE (object);
+
+  switch (prop_id) {
+    case PROP_DEVICE:
+      self->device_id = g_value_dup_string (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+struct _GstWasapi2DeviceProvider
+{
+  GstDeviceProvider parent;
+};
+
+G_DEFINE_TYPE (GstWasapi2DeviceProvider, gst_wasapi2_device_provider,
+    GST_TYPE_DEVICE_PROVIDER);
+
+static GList *gst_wasapi2_device_provider_probe (GstDeviceProvider * provider);
+
+static void
+gst_wasapi2_device_provider_class_init (GstWasapi2DeviceProviderClass * klass)
+{
+  GstDeviceProviderClass *provider_class = GST_DEVICE_PROVIDER_CLASS (klass);
+
+  provider_class->probe = GST_DEBUG_FUNCPTR (gst_wasapi2_device_provider_probe);
+
+  gst_device_provider_class_set_static_metadata (provider_class,
+      "WASAPI (Windows Audio Session API) Device Provider",
+      "Source/Sink/Audio", "List WASAPI source and sink devices",
+      "Nirbheek Chauhan <nirbheek@centricular.com>, "
+      "Seungha Yang <seungha@centricular.com>");
+}
+
+static void
+gst_wasapi2_device_provider_init (GstWasapi2DeviceProvider * provider)
+{
+}
+
+static void
+gst_wasapi2_device_provider_probe_internal (GstWasapi2DeviceProvider * self,
+    GstWasapi2ClientDeviceClass client_class, GList ** devices)
+{
+  gint i;
+  const gchar *device_class, *factory_name;
+
+  if (client_class == GST_WASAPI2_CLIENT_DEVICE_CLASS_RENDER) {
+    device_class = "Audio/Sink";
+    factory_name = "wasapi2sink";
+  } else {
+    device_class = "Audio/Source";
+    factory_name = "wasapi2src";
+  }
+
+  for (i = 0;; i++) {
+    GstWasapi2Client *client = NULL;
+    GstDevice *device;
+    GstStructure *props = NULL;
+    GstCaps *caps = NULL;
+    gchar *device_id = NULL;
+    gchar *device_name = NULL;
+
+    client = gst_wasapi2_client_new (client_class, FALSE, i, NULL);
+
+    if (!client)
+      return;
+
+    caps = gst_wasapi2_client_get_caps (client);
+    if (!caps) {
+      GST_WARNING_OBJECT (self, "Couldn't get caps from client %d", i);
+      goto next;
+    }
+
+    g_object_get (client,
+        "device", &device_id, "device-name", &device_name, NULL);
+    if (!device_id) {
+      GST_WARNING_OBJECT (self, "Couldn't get device name from client %d", i);
+      goto next;
+    }
+
+    if (!device_name) {
+      GST_WARNING_OBJECT (self, "Couldn't get device name from client %d", i);
+      goto next;
+    }
+
+    props = gst_structure_new ("wasapi2-proplist",
+        "device.api", G_TYPE_STRING, "wasapi",
+        "device.id", G_TYPE_STRING, device_id,
+        "device.default", G_TYPE_BOOLEAN, i == 0,
+        "wasapi.device.description", G_TYPE_STRING, device_name, NULL);
+
+    device = g_object_new (GST_TYPE_WASAPI2_DEVICE, "device", device_id,
+        "display-name", device_name, "caps", caps,
+        "device-class", device_class, "properties", props, NULL);
+    GST_WASAPI2_DEVICE (device)->factory_name = factory_name;
+
+    *devices = g_list_append (*devices, device);
+
+  next:
+    gst_clear_object (&client);
+    gst_clear_caps (&caps);
+    g_free (device_id);
+    g_free (device_name);
+    if (props)
+      gst_structure_free (props);
+  }
+
+  return;
+}
+
+static GList *
+gst_wasapi2_device_provider_probe (GstDeviceProvider * provider)
+{
+  GstWasapi2DeviceProvider *self = GST_WASAPI2_DEVICE_PROVIDER (provider);
+  GList *devices = NULL;
+
+  gst_wasapi2_device_provider_probe_internal (self,
+      GST_WASAPI2_CLIENT_DEVICE_CLASS_CAPTURE, &devices);
+  gst_wasapi2_device_provider_probe_internal (self,
+      GST_WASAPI2_CLIENT_DEVICE_CLASS_RENDER, &devices);
+
+  return devices;
+}
diff --git a/sys/wasapi2/gstwasapi2device.h b/sys/wasapi2/gstwasapi2device.h
new file mode 100644
index 000000000..697bba17e
--- /dev/null
+++ b/sys/wasapi2/gstwasapi2device.h
@@ -0,0 +1,37 @@
+/* GStreamer
+ * Copyright (C) 2020 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.
+ */
+
+#ifndef __GST_WASAPI2_DEVICE_H__
+#define __GST_WASAPI2_DEVICE_H__
+
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_WASAPI2_DEVICE (gst_wasapi2_device_get_type())
+#define GST_TYPE_WASAPI2_DEVICE_PROVIDER (gst_wasapi2_device_provider_get_type())
+
+G_DECLARE_FINAL_TYPE (GstWasapi2Device, gst_wasapi2_device,
+    GST, WASAPI2_DEVICE, GstDevice);
+G_DECLARE_FINAL_TYPE (GstWasapi2DeviceProvider, gst_wasapi2_device_provider,
+    GST, WASAPI2_DEVICE_PROVIDER, GstDeviceProvider);
+
+G_END_DECLS
+
+#endif /* __GST_WASAPI2_DEVICE_H__ */
\ No newline at end of file
diff --git a/sys/wasapi2/meson.build b/sys/wasapi2/meson.build
index 742c4846d..f5c774ce2 100644
--- a/sys/wasapi2/meson.build
+++ b/sys/wasapi2/meson.build
@@ -3,6 +3,7 @@ wasapi2_sources = [
   'gstwasapi2sink.c',
   'gstwasapi2util.c',
   'gstwasapi2client.cpp',
+  'gstwasapi2device.c',
   'plugin.c',
 ]
 
diff --git a/sys/wasapi2/plugin.c b/sys/wasapi2/plugin.c
index fa88cb008..b87785c55 100644
--- a/sys/wasapi2/plugin.c
+++ b/sys/wasapi2/plugin.c
@@ -25,6 +25,7 @@
 
 #include "gstwasapi2sink.h"
 #include "gstwasapi2src.h"
+#include "gstwasapi2device.h"
 
 GST_DEBUG_CATEGORY (gst_wasapi2_debug);
 GST_DEBUG_CATEGORY (gst_wasapi2_client_debug);
@@ -46,6 +47,9 @@ plugin_init (GstPlugin * plugin)
   gst_element_register (plugin, "wasapi2sink", rank, GST_TYPE_WASAPI2_SINK);
   gst_element_register (plugin, "wasapi2src", rank, GST_TYPE_WASAPI2_SRC);
 
+  gst_device_provider_register (plugin, "wasapi2deviceprovider",
+      rank, GST_TYPE_WASAPI2_DEVICE_PROVIDER);
+
   return TRUE;
 }