Merging gst-plugins-bad

1 files changed, 964 insertions, 0 deletions

diff --git a/sys/wasapi/gstwasapiutil.c b/sys/wasapi/gstwasapiutil.c
new file mode 100644
index 0000000000..b59f5f1936
--- /dev/null
+++ b/sys/wasapi/gstwasapiutil.c
@@ -0,0 +1,964 @@
+/*
+ * Copyright (C) 2008 Ole André Vadla Ravnås <ole.andre.ravnas@tandberg.com>
+ * Copyright (C) 2018 Centricular Ltd.
+ *   Author: Nirbheek Chauhan <nirbheek@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
+
+/* Note: initguid.h can not be included in gstwasapiutil.h, otherwise a
+ * symbol redefinition error will be raised.
+ * initguid.h must be included in the C file before mmdeviceapi.h
+ * which is included in gstwasapiutil.h.
+ */
+#ifdef _MSC_VER
+#include <initguid.h>
+#endif
+#include "gstwasapiutil.h"
+#include "gstwasapidevice.h"
+
+GST_DEBUG_CATEGORY_EXTERN (gst_wasapi_debug);
+#define GST_CAT_DEFAULT gst_wasapi_debug
+
+/* This was only added to MinGW in ~2015 and our Cerbero toolchain is too old */
+#if defined(_MSC_VER)
+#include <functiondiscoverykeys_devpkey.h>
+#elif !defined(PKEY_Device_FriendlyName)
+#include <initguid.h>
+#include <propkey.h>
+DEFINE_PROPERTYKEY (PKEY_Device_FriendlyName, 0xa45c254e, 0xdf1c, 0x4efd, 0x80,
+    0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0, 14);
+DEFINE_PROPERTYKEY (PKEY_AudioEngine_DeviceFormat, 0xf19f064d, 0x82c, 0x4e27,
+    0xbc, 0x73, 0x68, 0x82, 0xa1, 0xbb, 0x8e, 0x4c, 0);
+#endif
+
+/* __uuidof is only available in C++, so we hard-code the GUID values for all
+ * these. This is ok because these are ABI. */
+const CLSID CLSID_MMDeviceEnumerator = { 0xbcde0395, 0xe52f, 0x467c,
+  {0x8e, 0x3d, 0xc4, 0x57, 0x92, 0x91, 0x69, 0x2e}
+};
+
+const IID IID_IMMDeviceEnumerator = { 0xa95664d2, 0x9614, 0x4f35,
+  {0xa7, 0x46, 0xde, 0x8d, 0xb6, 0x36, 0x17, 0xe6}
+};
+
+const IID IID_IMMEndpoint = { 0x1be09788, 0x6894, 0x4089,
+  {0x85, 0x86, 0x9a, 0x2a, 0x6c, 0x26, 0x5a, 0xc5}
+};
+
+const IID IID_IAudioClient = { 0x1cb9ad4c, 0xdbfa, 0x4c32,
+  {0xb1, 0x78, 0xc2, 0xf5, 0x68, 0xa7, 0x03, 0xb2}
+};
+
+const IID IID_IAudioClient3 = { 0x7ed4ee07, 0x8e67, 0x4cd4,
+  {0x8c, 0x1a, 0x2b, 0x7a, 0x59, 0x87, 0xad, 0x42}
+};
+
+const IID IID_IAudioClock = { 0xcd63314f, 0x3fba, 0x4a1b,
+  {0x81, 0x2c, 0xef, 0x96, 0x35, 0x87, 0x28, 0xe7}
+};
+
+const IID IID_IAudioCaptureClient = { 0xc8adbd64, 0xe71e, 0x48a0,
+  {0xa4, 0xde, 0x18, 0x5c, 0x39, 0x5c, 0xd3, 0x17}
+};
+
+const IID IID_IAudioRenderClient = { 0xf294acfc, 0x3146, 0x4483,
+  {0xa7, 0xbf, 0xad, 0xdc, 0xa7, 0xc2, 0x60, 0xe2}
+};
+
+/* *INDENT-OFF* */
+static struct
+{
+  guint64 wasapi_pos;
+  GstAudioChannelPosition gst_pos;
+} wasapi_to_gst_pos[] = {
+  {SPEAKER_FRONT_LEFT, GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT},
+  {SPEAKER_FRONT_RIGHT, GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT},
+  {SPEAKER_FRONT_CENTER, GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER},
+  {SPEAKER_LOW_FREQUENCY, GST_AUDIO_CHANNEL_POSITION_LFE1},
+  {SPEAKER_BACK_LEFT, GST_AUDIO_CHANNEL_POSITION_REAR_LEFT},
+  {SPEAKER_BACK_RIGHT, GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT},
+  {SPEAKER_FRONT_LEFT_OF_CENTER,
+      GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER},
+  {SPEAKER_FRONT_RIGHT_OF_CENTER,
+      GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER},
+  {SPEAKER_BACK_CENTER, GST_AUDIO_CHANNEL_POSITION_REAR_CENTER},
+  /* Enum values diverge from this point onwards */
+  {SPEAKER_SIDE_LEFT, GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT},
+  {SPEAKER_SIDE_RIGHT, GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT},
+  {SPEAKER_TOP_CENTER, GST_AUDIO_CHANNEL_POSITION_TOP_CENTER},
+  {SPEAKER_TOP_FRONT_LEFT, GST_AUDIO_CHANNEL_POSITION_TOP_FRONT_LEFT},
+  {SPEAKER_TOP_FRONT_CENTER, GST_AUDIO_CHANNEL_POSITION_TOP_FRONT_CENTER},
+  {SPEAKER_TOP_FRONT_RIGHT, GST_AUDIO_CHANNEL_POSITION_TOP_FRONT_RIGHT},
+  {SPEAKER_TOP_BACK_LEFT, GST_AUDIO_CHANNEL_POSITION_TOP_REAR_LEFT},
+  {SPEAKER_TOP_BACK_CENTER, GST_AUDIO_CHANNEL_POSITION_TOP_REAR_CENTER},
+  {SPEAKER_TOP_BACK_RIGHT, GST_AUDIO_CHANNEL_POSITION_TOP_REAR_RIGHT}
+};
+/* *INDENT-ON* */
+
+static int windows_major_version = 0;
+
+gboolean
+gst_wasapi_util_have_audioclient3 (void)
+{
+  if (windows_major_version > 0)
+    return windows_major_version == 10;
+
+  if (g_getenv ("GST_WASAPI_DISABLE_AUDIOCLIENT3") != NULL) {
+    windows_major_version = 6;
+    return FALSE;
+  }
+
+  /* https://msdn.microsoft.com/en-us/library/windows/desktop/ms724834(v=vs.85).aspx */
+  windows_major_version = 6;
+  if (g_win32_check_windows_version (10, 0, 0, G_WIN32_OS_ANY))
+    windows_major_version = 10;
+
+  return windows_major_version == 10;
+}
+
+GType
+gst_wasapi_device_role_get_type (void)
+{
+  static const GEnumValue values[] = {
+    {GST_WASAPI_DEVICE_ROLE_CONSOLE,
+        "Games, system notifications, voice commands", "console"},
+    {GST_WASAPI_DEVICE_ROLE_MULTIMEDIA, "Music, movies, recorded media",
+        "multimedia"},
+    {GST_WASAPI_DEVICE_ROLE_COMMS, "Voice communications", "comms"},
+    {0, NULL, NULL}
+  };
+  static GType id = 0;
+
+  if (g_once_init_enter ((gsize *) & id)) {
+    GType _id;
+
+    _id = g_enum_register_static ("GstWasapiDeviceRole", values);
+
+    g_once_init_leave ((gsize *) & id, _id);
+  }
+
+  return id;
+}
+
+gint
+gst_wasapi_device_role_to_erole (gint role)
+{
+  switch (role) {
+    case GST_WASAPI_DEVICE_ROLE_CONSOLE:
+      return eConsole;
+    case GST_WASAPI_DEVICE_ROLE_MULTIMEDIA:
+      return eMultimedia;
+    case GST_WASAPI_DEVICE_ROLE_COMMS:
+      return eCommunications;
+    default:
+      g_assert_not_reached ();
+  }
+
+  return -1;
+}
+
+gint
+gst_wasapi_erole_to_device_role (gint erole)
+{
+  switch (erole) {
+    case eConsole:
+      return GST_WASAPI_DEVICE_ROLE_CONSOLE;
+    case eMultimedia:
+      return GST_WASAPI_DEVICE_ROLE_MULTIMEDIA;
+    case eCommunications:
+      return GST_WASAPI_DEVICE_ROLE_COMMS;
+    default:
+      g_assert_not_reached ();
+  }
+
+  return -1;
+}
+
+static const gchar *
+hresult_to_string_fallback (HRESULT hr)
+{
+  const gchar *s = "unknown error";
+
+  switch (hr) {
+    case AUDCLNT_E_NOT_INITIALIZED:
+      s = "AUDCLNT_E_NOT_INITIALIZED";
+      break;
+    case AUDCLNT_E_ALREADY_INITIALIZED:
+      s = "AUDCLNT_E_ALREADY_INITIALIZED";
+      break;
+    case AUDCLNT_E_WRONG_ENDPOINT_TYPE:
+      s = "AUDCLNT_E_WRONG_ENDPOINT_TYPE";
+      break;
+    case AUDCLNT_E_DEVICE_INVALIDATED:
+      s = "AUDCLNT_E_DEVICE_INVALIDATED";
+      break;
+    case AUDCLNT_E_NOT_STOPPED:
+      s = "AUDCLNT_E_NOT_STOPPED";
+      break;
+    case AUDCLNT_E_BUFFER_TOO_LARGE:
+      s = "AUDCLNT_E_BUFFER_TOO_LARGE";
+      break;
+    case AUDCLNT_E_OUT_OF_ORDER:
+      s = "AUDCLNT_E_OUT_OF_ORDER";
+      break;
+    case AUDCLNT_E_UNSUPPORTED_FORMAT:
+      s = "AUDCLNT_E_UNSUPPORTED_FORMAT";
+      break;
+    case AUDCLNT_E_INVALID_DEVICE_PERIOD:
+      s = "AUDCLNT_E_INVALID_DEVICE_PERIOD";
+      break;
+    case AUDCLNT_E_INVALID_SIZE:
+      s = "AUDCLNT_E_INVALID_SIZE";
+      break;
+    case AUDCLNT_E_DEVICE_IN_USE:
+      s = "AUDCLNT_E_DEVICE_IN_USE";
+      break;
+    case AUDCLNT_E_BUFFER_OPERATION_PENDING:
+      s = "AUDCLNT_E_BUFFER_OPERATION_PENDING";
+      break;
+    case AUDCLNT_E_BUFFER_SIZE_ERROR:
+      s = "AUDCLNT_E_BUFFER_SIZE_ERROR";
+      break;
+    case AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED:
+      s = "AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED";
+      break;
+    case AUDCLNT_E_THREAD_NOT_REGISTERED:
+      s = "AUDCLNT_E_THREAD_NOT_REGISTERED";
+      break;
+    case AUDCLNT_E_EXCLUSIVE_MODE_NOT_ALLOWED:
+      s = "AUDCLNT_E_EXCLUSIVE_MODE_NOT_ALLOWED";
+      break;
+    case AUDCLNT_E_ENDPOINT_CREATE_FAILED:
+      s = "AUDCLNT_E_ENDPOINT_CREATE_FAILED";
+      break;
+    case AUDCLNT_E_SERVICE_NOT_RUNNING:
+      s = "AUDCLNT_E_SERVICE_NOT_RUNNING";
+      break;
+    case AUDCLNT_E_EVENTHANDLE_NOT_EXPECTED:
+      s = "AUDCLNT_E_EVENTHANDLE_NOT_EXPECTED";
+      break;
+    case AUDCLNT_E_EXCLUSIVE_MODE_ONLY:
+      s = "AUDCLNT_E_EXCLUSIVE_MODE_ONLY";
+      break;
+    case AUDCLNT_E_BUFDURATION_PERIOD_NOT_EQUAL:
+      s = "AUDCLNT_E_BUFDURATION_PERIOD_NOT_EQUAL";
+      break;
+    case AUDCLNT_E_EVENTHANDLE_NOT_SET:
+      s = "AUDCLNT_E_EVENTHANDLE_NOT_SET";
+      break;
+    case AUDCLNT_E_INCORRECT_BUFFER_SIZE:
+      s = "AUDCLNT_E_INCORRECT_BUFFER_SIZE";
+      break;
+    case AUDCLNT_E_CPUUSAGE_EXCEEDED:
+      s = "AUDCLNT_E_CPUUSAGE_EXCEEDED";
+      break;
+    case AUDCLNT_S_BUFFER_EMPTY:
+      s = "AUDCLNT_S_BUFFER_EMPTY";
+      break;
+    case AUDCLNT_S_THREAD_ALREADY_REGISTERED:
+      s = "AUDCLNT_S_THREAD_ALREADY_REGISTERED";
+      break;
+    case AUDCLNT_S_POSITION_STALLED:
+      s = "AUDCLNT_S_POSITION_STALLED";
+      break;
+    case E_POINTER:
+      s = "E_POINTER";
+      break;
+    case E_INVALIDARG:
+      s = "E_INVALIDARG";
+      break;
+  }
+
+  return s;
+}
+
+gchar *
+gst_wasapi_util_hresult_to_string (HRESULT hr)
+{
+  gchar *error_text = NULL;
+
+  error_text = g_win32_error_message ((gint) hr);
+  /* g_win32_error_message() seems to be returning empty string for
+   * AUDCLNT_* cases */
+  if (!error_text || strlen (error_text) == 0) {
+    g_free (error_text);
+    error_text = g_strdup (hresult_to_string_fallback (hr));
+  }
+
+  return error_text;
+}
+
+gboolean
+gst_wasapi_util_get_devices (GstMMDeviceEnumerator * self,
+    gboolean active, GList ** devices)
+{
+  gboolean res = FALSE;
+  static GstStaticCaps scaps = GST_STATIC_CAPS (GST_WASAPI_STATIC_CAPS);
+  DWORD dwStateMask = active ? DEVICE_STATE_ACTIVE : DEVICE_STATEMASK_ALL;
+  IMMDeviceCollection *device_collection = NULL;
+  IMMDeviceEnumerator *enum_handle = NULL;
+  const gchar *device_class, *element_name;
+  guint ii, count;
+  HRESULT hr;
+
+  *devices = NULL;
+
+  if (!self)
+    return FALSE;
+
+  enum_handle = gst_mm_device_enumerator_get_handle (self);
+  if (!enum_handle)
+    return FALSE;
+
+  hr = IMMDeviceEnumerator_EnumAudioEndpoints (enum_handle, eAll, dwStateMask,
+      &device_collection);
+  HR_FAILED_GOTO (hr, IMMDeviceEnumerator::EnumAudioEndpoints, err);
+
+  hr = IMMDeviceCollection_GetCount (device_collection, &count);
+  HR_FAILED_GOTO (hr, IMMDeviceCollection::GetCount, err);
+
+  /* Create a GList of GstDevices* to return */
+  for (ii = 0; ii < count; ii++) {
+    IMMDevice *item = NULL;
+    IMMEndpoint *endpoint = NULL;
+    IAudioClient *client = NULL;
+    IPropertyStore *prop_store = NULL;
+    WAVEFORMATEX *format = NULL;
+    gchar *description = NULL;
+    gchar *strid = NULL;
+    EDataFlow dataflow;
+    PROPVARIANT var;
+    wchar_t *wstrid;
+    GstDevice *device;
+    GstStructure *props;
+    GstCaps *caps;
+
+    hr = IMMDeviceCollection_Item (device_collection, ii, &item);
+    if (hr != S_OK)
+      continue;
+
+    hr = IMMDevice_QueryInterface (item, &IID_IMMEndpoint, (void **) &endpoint);
+    if (hr != S_OK)
+      goto next;
+
+    hr = IMMEndpoint_GetDataFlow (endpoint, &dataflow);
+    if (hr != S_OK)
+      goto next;
+
+    if (dataflow == eRender) {
+      device_class = "Audio/Sink";
+      element_name = "wasapisink";
+    } else {
+      device_class = "Audio/Source";
+      element_name = "wasapisrc";
+    }
+
+    PropVariantInit (&var);
+
+    hr = IMMDevice_GetId (item, &wstrid);
+    if (hr != S_OK)
+      goto next;
+    strid = g_utf16_to_utf8 (wstrid, -1, NULL, NULL, NULL);
+    CoTaskMemFree (wstrid);
+
+    hr = IMMDevice_OpenPropertyStore (item, STGM_READ, &prop_store);
+    if (hr != S_OK)
+      goto next;
+
+    /* NOTE: More properties can be added as needed from here:
+     * https://msdn.microsoft.com/en-us/library/windows/desktop/dd370794(v=vs.85).aspx */
+    hr = IPropertyStore_GetValue (prop_store, &PKEY_Device_FriendlyName, &var);
+    if (hr != S_OK)
+      goto next;
+    description = g_utf16_to_utf8 (var.pwszVal, -1, NULL, NULL, NULL);
+    PropVariantClear (&var);
+
+    /* Get the audio client so we can fetch the mix format for shared mode
+     * to get the device format for exclusive mode (or something close to that)
+     * fetch PKEY_AudioEngine_DeviceFormat from the property store. */
+    hr = IMMDevice_Activate (item, &IID_IAudioClient, CLSCTX_ALL, NULL,
+        (void **) &client);
+    if (hr != S_OK) {
+      gchar *msg = gst_wasapi_util_hresult_to_string (hr);
+      GST_ERROR_OBJECT (self, "IMMDevice::Activate (IID_IAudioClient) failed"
+          "on %s: %s", strid, msg);
+      g_free (msg);
+      goto next;
+    }
+
+    hr = IAudioClient_GetMixFormat (client, &format);
+    if (hr != S_OK || format == NULL) {
+      gchar *msg = gst_wasapi_util_hresult_to_string (hr);
+      GST_ERROR_OBJECT (self, "GetMixFormat failed on %s: %s", strid, msg);
+      g_free (msg);
+      goto next;
+    }
+
+    if (!gst_wasapi_util_parse_waveformatex ((WAVEFORMATEXTENSIBLE *) format,
+            gst_static_caps_get (&scaps), &caps, NULL))
+      goto next;
+
+    /* Set some useful properties */
+    props = gst_structure_new ("wasapi-proplist",
+        "device.api", G_TYPE_STRING, "wasapi",
+        "device.strid", G_TYPE_STRING, GST_STR_NULL (strid),
+        "wasapi.device.description", G_TYPE_STRING, description, NULL);
+
+    device = g_object_new (GST_TYPE_WASAPI_DEVICE, "device", strid,
+        "display-name", description, "caps", caps,
+        "device-class", device_class, "properties", props, NULL);
+    GST_WASAPI_DEVICE (device)->element = element_name;
+
+    gst_structure_free (props);
+    gst_caps_unref (caps);
+    *devices = g_list_prepend (*devices, device);
+
+  next:
+    PropVariantClear (&var);
+    if (prop_store)
+      IUnknown_Release (prop_store);
+    if (endpoint)
+      IUnknown_Release (endpoint);
+    if (client)
+      IUnknown_Release (client);
+    if (item)
+      IUnknown_Release (item);
+    if (description)
+      g_free (description);
+    if (strid)
+      g_free (strid);
+  }
+
+  res = TRUE;
+
+err:
+  if (device_collection)
+    IUnknown_Release (device_collection);
+  return res;
+}
+
+gboolean
+gst_wasapi_util_get_device_format (GstElement * self,
+    gint device_mode, IMMDevice * device, IAudioClient * client,
+    WAVEFORMATEX ** ret_format)
+{
+  WAVEFORMATEX *format;
+  HRESULT hr;
+
+  *ret_format = NULL;
+
+  hr = IAudioClient_GetMixFormat (client, &format);
+  HR_FAILED_RET (hr, IAudioClient::GetMixFormat, FALSE);
+
+  /* WASAPI always accepts the format returned by GetMixFormat in shared mode */
+  if (device_mode == AUDCLNT_SHAREMODE_SHARED)
+    goto out;
+
+  /* WASAPI may or may not support this format in exclusive mode */
+  hr = IAudioClient_IsFormatSupported (client, AUDCLNT_SHAREMODE_EXCLUSIVE,
+      format, NULL);
+  if (hr == S_OK)
+    goto out;
+
+  CoTaskMemFree (format);
+
+  /* Open the device property store, and get the format that WASAPI has been
+   * using for sending data to the device */
+  {
+    PROPVARIANT var;
+    IPropertyStore *prop_store = NULL;
+
+    hr = IMMDevice_OpenPropertyStore (device, STGM_READ, &prop_store);
+    HR_FAILED_RET (hr, IMMDevice::OpenPropertyStore, FALSE);
+
+    hr = IPropertyStore_GetValue (prop_store, &PKEY_AudioEngine_DeviceFormat,
+        &var);
+    if (hr != S_OK) {
+      gchar *msg = gst_wasapi_util_hresult_to_string (hr);
+      GST_ERROR_OBJECT (self, "GetValue failed: %s", msg);
+      g_free (msg);
+      IUnknown_Release (prop_store);
+      return FALSE;
+    }
+
+    format = malloc (var.blob.cbSize);
+    memcpy (format, var.blob.pBlobData, var.blob.cbSize);
+
+    PropVariantClear (&var);
+    IUnknown_Release (prop_store);
+  }
+
+  /* WASAPI may or may not support this format in exclusive mode */
+  hr = IAudioClient_IsFormatSupported (client, AUDCLNT_SHAREMODE_EXCLUSIVE,
+      format, NULL);
+  if (hr == S_OK)
+    goto out;
+
+  GST_ERROR_OBJECT (self, "AudioEngine DeviceFormat not supported");
+  free (format);
+  return FALSE;
+
+out:
+  *ret_format = format;
+  return TRUE;
+}
+
+gboolean
+gst_wasapi_util_get_device (GstMMDeviceEnumerator * self,
+    gint data_flow, gint role, const wchar_t * device_strid,
+    IMMDevice ** ret_device)
+{
+  gboolean res = FALSE;
+  HRESULT hr;
+  IMMDeviceEnumerator *enum_handle = NULL;
+  IMMDevice *device = NULL;
+
+  if (!self)
+    return FALSE;
+
+  enum_handle = gst_mm_device_enumerator_get_handle (self);
+  if (!enum_handle)
+    return FALSE;
+
+  if (!device_strid) {
+    hr = IMMDeviceEnumerator_GetDefaultAudioEndpoint (enum_handle, data_flow,
+        role, &device);
+    HR_FAILED_GOTO (hr, IMMDeviceEnumerator::GetDefaultAudioEndpoint, beach);
+  } else {
+    hr = IMMDeviceEnumerator_GetDevice (enum_handle, device_strid, &device);
+    if (hr != S_OK) {
+      gchar *msg = gst_wasapi_util_hresult_to_string (hr);
+      GST_ERROR_OBJECT (self, "IMMDeviceEnumerator::GetDevice (%S) failed"
+          ": %s", device_strid, msg);
+      g_free (msg);
+      goto beach;
+    }
+  }
+
+  IUnknown_AddRef (device);
+  *ret_device = device;
+
+  res = TRUE;
+
+beach:
+  if (device != NULL)
+    IUnknown_Release (device);
+
+  return res;
+}
+
+gboolean
+gst_wasapi_util_get_audio_client (GstElement * self,
+    IMMDevice * device, IAudioClient ** ret_client)
+{
+  IAudioClient *client = NULL;
+  gboolean res = FALSE;
+  HRESULT hr;
+
+  if (gst_wasapi_util_have_audioclient3 ())
+    hr = IMMDevice_Activate (device, &IID_IAudioClient3, CLSCTX_ALL, NULL,
+        (void **) &client);
+  else
+    hr = IMMDevice_Activate (device, &IID_IAudioClient, CLSCTX_ALL, NULL,
+        (void **) &client);
+  HR_FAILED_GOTO (hr, IMMDevice::Activate (IID_IAudioClient), beach);
+
+  IUnknown_AddRef (client);
+  *ret_client = client;
+
+  res = TRUE;
+
+beach:
+  if (client != NULL)
+    IUnknown_Release (client);
+
+  return res;
+}
+
+gboolean
+gst_wasapi_util_get_render_client (GstElement * self, IAudioClient * client,
+    IAudioRenderClient ** ret_render_client)
+{
+  gboolean res = FALSE;
+  HRESULT hr;
+  IAudioRenderClient *render_client = NULL;
+
+  hr = IAudioClient_GetService (client, &IID_IAudioRenderClient,
+      (void **) &render_client);
+  HR_FAILED_GOTO (hr, IAudioClient::GetService, beach);
+
+  *ret_render_client = render_client;
+  res = TRUE;
+
+beach:
+  return res;
+}
+
+gboolean
+gst_wasapi_util_get_capture_client (GstElement * self, IAudioClient * client,
+    IAudioCaptureClient ** ret_capture_client)
+{
+  gboolean res = FALSE;
+  HRESULT hr;
+  IAudioCaptureClient *capture_client = NULL;
+
+  hr = IAudioClient_GetService (client, &IID_IAudioCaptureClient,
+      (void **) &capture_client);
+  HR_FAILED_GOTO (hr, IAudioClient::GetService, beach);
+
+  *ret_capture_client = capture_client;
+  res = TRUE;
+
+beach:
+  return res;
+}
+
+gboolean
+gst_wasapi_util_get_clock (GstElement * self, IAudioClient * client,
+    IAudioClock ** ret_clock)
+{
+  gboolean res = FALSE;
+  HRESULT hr;
+  IAudioClock *clock = NULL;
+
+  hr = IAudioClient_GetService (client, &IID_IAudioClock, (void **) &clock);
+  HR_FAILED_GOTO (hr, IAudioClient::GetService, beach);
+
+  *ret_clock = clock;
+  res = TRUE;
+
+beach:
+  return res;
+}
+
+static const gchar *
+gst_waveformatex_to_audio_format (WAVEFORMATEXTENSIBLE * format)
+{
+  const gchar *fmt_str = NULL;
+  GstAudioFormat fmt = GST_AUDIO_FORMAT_UNKNOWN;
+
+  if (format->Format.wFormatTag == WAVE_FORMAT_PCM) {
+    fmt = gst_audio_format_build_integer (TRUE, G_LITTLE_ENDIAN,
+        format->Format.wBitsPerSample, format->Format.wBitsPerSample);
+  } else if (format->Format.wFormatTag == WAVE_FORMAT_IEEE_FLOAT) {
+    if (format->Format.wBitsPerSample == 32)
+      fmt = GST_AUDIO_FORMAT_F32LE;
+    else if (format->Format.wBitsPerSample == 64)
+      fmt = GST_AUDIO_FORMAT_F64LE;
+  } else if (format->Format.wFormatTag == WAVE_FORMAT_EXTENSIBLE) {
+    if (IsEqualGUID (&format->SubFormat, &KSDATAFORMAT_SUBTYPE_PCM)) {
+      fmt = gst_audio_format_build_integer (TRUE, G_LITTLE_ENDIAN,
+          format->Format.wBitsPerSample, format->Samples.wValidBitsPerSample);
+    } else if (IsEqualGUID (&format->SubFormat,
+            &KSDATAFORMAT_SUBTYPE_IEEE_FLOAT)) {
+      if (format->Format.wBitsPerSample == 32
+          && format->Samples.wValidBitsPerSample == 32)
+        fmt = GST_AUDIO_FORMAT_F32LE;
+      else if (format->Format.wBitsPerSample == 64 &&
+          format->Samples.wValidBitsPerSample == 64)
+        fmt = GST_AUDIO_FORMAT_F64LE;
+    }
+  }
+
+  if (fmt != GST_AUDIO_FORMAT_UNKNOWN)
+    fmt_str = gst_audio_format_to_string (fmt);
+
+  return fmt_str;
+}
+
+static void
+gst_wasapi_util_channel_position_all_none (guint channels,
+    GstAudioChannelPosition * position)
+{
+  int ii;
+  for (ii = 0; ii < channels; ii++)
+    position[ii] = GST_AUDIO_CHANNEL_POSITION_NONE;
+}
+
+/* Parse WAVEFORMATEX to get the gstreamer channel mask, and the wasapi channel
+ * positions so GstAudioRingbuffer can reorder the audio data to match the
+ * gstreamer channel order. */
+static guint64
+gst_wasapi_util_waveformatex_to_channel_mask (WAVEFORMATEXTENSIBLE * format,
+    GstAudioChannelPosition ** out_position)
+{
+  int ii, ch;
+  guint64 mask = 0;
+  WORD nChannels = format->Format.nChannels;
+  DWORD dwChannelMask = format->dwChannelMask;
+  GstAudioChannelPosition *pos = NULL;
+
+  pos = g_new (GstAudioChannelPosition, nChannels);
+  gst_wasapi_util_channel_position_all_none (nChannels, pos);
+
+  /* Too many channels, have to assume that they are all non-positional */
+  if (nChannels > G_N_ELEMENTS (wasapi_to_gst_pos)) {
+    GST_INFO ("Got too many (%i) channels, assuming non-positional", nChannels);
+    goto out;
+  }
+
+  /* Too many bits in the channel mask, and the bits don't match nChannels */
+  if (dwChannelMask >> (G_N_ELEMENTS (wasapi_to_gst_pos) + 1) != 0) {
+    GST_WARNING ("Too many bits in channel mask (%lu), assuming "
+        "non-positional", dwChannelMask);
+    goto out;
+  }
+
+  /* Map WASAPI's channel mask to Gstreamer's channel mask and positions.
+   * If the no. of bits in the mask > nChannels, we will ignore the extra. */
+  for (ii = 0, ch = 0; ii < G_N_ELEMENTS (wasapi_to_gst_pos) && ch < nChannels;
+      ii++) {
+    if (!(dwChannelMask & wasapi_to_gst_pos[ii].wasapi_pos))
+      /* no match, try next */
+      continue;
+    mask |= G_GUINT64_CONSTANT (1) << wasapi_to_gst_pos[ii].gst_pos;
+    pos[ch++] = wasapi_to_gst_pos[ii].gst_pos;
+  }
+
+  /* XXX: Warn if some channel masks couldn't be mapped? */
+
+  GST_DEBUG ("Converted WASAPI mask 0x%" G_GINT64_MODIFIER "x -> 0x%"
+      G_GINT64_MODIFIER "x", (guint64) dwChannelMask, (guint64) mask);
+
+out:
+  if (out_position)
+    *out_position = pos;
+  return mask;
+}
+
+gboolean
+gst_wasapi_util_parse_waveformatex (WAVEFORMATEXTENSIBLE * format,
+    GstCaps * template_caps, GstCaps ** out_caps,
+    GstAudioChannelPosition ** out_positions)
+{
+  int ii;
+  const gchar *afmt;
+  guint64 channel_mask;
+
+  *out_caps = NULL;
+
+  /* TODO: handle SPDIF and other encoded formats */
+
+  /* 1 or 2 channels <= 16 bits sample size OR
+   * 1 or 2 channels > 16 bits sample size or >2 channels */
+  if (format->Format.wFormatTag != WAVE_FORMAT_PCM &&
+      format->Format.wFormatTag != WAVE_FORMAT_IEEE_FLOAT &&
+      format->Format.wFormatTag != WAVE_FORMAT_EXTENSIBLE)
+    /* Unhandled format tag */
+    return FALSE;
+
+  /* WASAPI can only tell us one canonical mix format that it will accept. The
+   * alternative is calling IsFormatSupported on all combinations of formats.
+   * Instead, it's simpler and faster to require conversion inside gstreamer */
+  afmt = gst_waveformatex_to_audio_format (format);
+  if (afmt == NULL)
+    return FALSE;
+
+  *out_caps = gst_caps_copy (template_caps);
+
+  /* This will always return something that might be usable */
+  channel_mask =
+      gst_wasapi_util_waveformatex_to_channel_mask (format, out_positions);
+
+  for (ii = 0; ii < gst_caps_get_size (*out_caps); ii++) {
+    GstStructure *s = gst_caps_get_structure (*out_caps, ii);
+
+    gst_structure_set (s,
+        "format", G_TYPE_STRING, afmt,
+        "channels", G_TYPE_INT, format->Format.nChannels,
+        "rate", G_TYPE_INT, format->Format.nSamplesPerSec, NULL);
+
+    if (channel_mask) {
+      gst_structure_set (s,
+          "channel-mask", GST_TYPE_BITMASK, channel_mask, NULL);
+    }
+  }
+
+  return TRUE;
+}
+
+void
+gst_wasapi_util_get_best_buffer_sizes (GstAudioRingBufferSpec * spec,
+    gboolean exclusive, REFERENCE_TIME default_period,
+    REFERENCE_TIME min_period, REFERENCE_TIME * ret_period,
+    REFERENCE_TIME * ret_buffer_duration)
+{
+  REFERENCE_TIME use_period, use_buffer;
+
+  /* Figure out what integral device period to use as the base */
+  if (exclusive) {
+    /* Exclusive mode can run at multiples of either the minimum period or the
+     * default period; these are on the hardware ringbuffer */
+    if (spec->latency_time * 10 > default_period)
+      use_period = default_period;
+    else
+      use_period = min_period;
+  } else {
+    /* Shared mode always runs at the default period, so if we want a larger
+     * period (for lower CPU usage), we do it as a multiple of that */
+    use_period = default_period;
+  }
+
+  /* Ensure that the period (latency_time) used is an integral multiple of
+   * either the default period or the minimum period */
+  use_period = use_period * MAX ((spec->latency_time * 10) / use_period, 1);
+
+  if (exclusive) {
+    /* Buffer duration is the same as the period in exclusive mode. The
+     * hardware is always writing out one buffer (of size *ret_period), and
+     * we're writing to the other one. */
+    use_buffer = use_period;
+  } else {
+    /* Ask WASAPI to create a software ringbuffer of at least this size; it may
+     * be larger so the actual buffer time may be different, which is why after
+     * initialization we read the buffer duration actually in-use and set
+     * segsize/segtotal from that. */
+    use_buffer = spec->buffer_time * 10;
+    /* Has to be at least twice the period */
+    if (use_buffer < 2 * use_period)
+      use_buffer = 2 * use_period;
+  }
+
+  *ret_period = use_period;
+  *ret_buffer_duration = use_buffer;
+}
+
+gboolean
+gst_wasapi_util_initialize_audioclient (GstElement * self,
+    GstAudioRingBufferSpec * spec, IAudioClient * client,
+    WAVEFORMATEX * format, guint sharemode, gboolean low_latency,
+    gboolean loopback, guint * ret_devicep_frames)
+{
+  REFERENCE_TIME default_period, min_period;
+  REFERENCE_TIME device_period, device_buffer_duration;
+  guint rate, stream_flags;
+  guint32 n_frames;
+  HRESULT hr;
+
+  hr = IAudioClient_GetDevicePeriod (client, &default_period, &min_period);
+  HR_FAILED_RET (hr, IAudioClient::GetDevicePeriod, FALSE);
+
+  GST_INFO_OBJECT (self, "wasapi default period: %" G_GINT64_FORMAT
+      ", min period: %" G_GINT64_FORMAT, default_period, min_period);
+
+  rate = GST_AUDIO_INFO_RATE (&spec->info);
+
+  if (low_latency) {
+    if (sharemode == AUDCLNT_SHAREMODE_SHARED) {
+      device_period = default_period;
+      device_buffer_duration = 0;
+    } else {
+      device_period = min_period;
+      device_buffer_duration = min_period;
+    }
+  } else {
+    /* Clamp values to integral multiples of an appropriate period */
+    gst_wasapi_util_get_best_buffer_sizes (spec,
+        sharemode == AUDCLNT_SHAREMODE_EXCLUSIVE, default_period,
+        min_period, &device_period, &device_buffer_duration);
+  }
+
+  stream_flags = AUDCLNT_STREAMFLAGS_EVENTCALLBACK;
+  if (loopback)
+    stream_flags |= AUDCLNT_STREAMFLAGS_LOOPBACK;
+
+  hr = IAudioClient_Initialize (client, sharemode, stream_flags,
+      device_buffer_duration,
+      /* This must always be 0 in shared mode */
+      sharemode == AUDCLNT_SHAREMODE_SHARED ? 0 : device_period, format, NULL);
+
+  if (hr == AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED &&
+      sharemode == AUDCLNT_SHAREMODE_EXCLUSIVE) {
+    GST_WARNING_OBJECT (self, "initialize failed due to unaligned period %i",
+        (int) device_period);
+
+    /* Calculate a new aligned period. First get the aligned buffer size. */
+    hr = IAudioClient_GetBufferSize (client, &n_frames);
+    HR_FAILED_RET (hr, IAudioClient::GetBufferSize, FALSE);
+
+    device_period = (GST_SECOND / 100) * n_frames / rate;
+
+    GST_WARNING_OBJECT (self, "trying to re-initialize with period %i "
+        "(%i frames, %i rate)", (int) device_period, n_frames, rate);
+
+    hr = IAudioClient_Initialize (client, sharemode, stream_flags,
+        device_period, device_period, format, NULL);
+  }
+  HR_FAILED_RET (hr, IAudioClient::Initialize, FALSE);
+
+  if (sharemode == AUDCLNT_SHAREMODE_EXCLUSIVE) {
+    /* We use the device period for the segment size and that needs to match
+     * the buffer size exactly when we write into it */
+    hr = IAudioClient_GetBufferSize (client, &n_frames);
+    HR_FAILED_RET (hr, IAudioClient::GetBufferSize, FALSE);
+
+    *ret_devicep_frames = n_frames;
+  } else {
+    /* device_period can be a non-power-of-10 value so round while converting */
+    *ret_devicep_frames =
+        gst_util_uint64_scale_round (device_period, rate * 100, GST_SECOND);
+  }
+
+  return TRUE;
+}
+
+gboolean
+gst_wasapi_util_initialize_audioclient3 (GstElement * self,
+    GstAudioRingBufferSpec * spec, IAudioClient3 * client,
+    WAVEFORMATEX * format, gboolean low_latency, gboolean loopback,
+    guint * ret_devicep_frames)
+{
+  HRESULT hr;
+  gint stream_flags;
+  guint devicep_frames;
+  guint defaultp_frames, fundp_frames, minp_frames, maxp_frames;
+  WAVEFORMATEX *tmpf;
+
+  hr = IAudioClient3_GetSharedModeEnginePeriod (client, format,
+      &defaultp_frames, &fundp_frames, &minp_frames, &maxp_frames);
+  HR_FAILED_RET (hr, IAudioClient3::GetSharedModeEnginePeriod, FALSE);
+
+  GST_INFO_OBJECT (self, "Using IAudioClient3, default period %i frames, "
+      "fundamental period %i frames, minimum period %i frames, maximum period "
+      "%i frames", defaultp_frames, fundp_frames, minp_frames, maxp_frames);
+
+  if (low_latency)
+    devicep_frames = minp_frames;
+  else
+    /* Just pick the max period, because lower values can cause glitches
+     * https://bugzilla.gnome.org/show_bug.cgi?id=794497 */
+    devicep_frames = maxp_frames;
+
+  stream_flags = AUDCLNT_STREAMFLAGS_EVENTCALLBACK;
+  if (loopback)
+    stream_flags |= AUDCLNT_STREAMFLAGS_LOOPBACK;
+
+  hr = IAudioClient3_InitializeSharedAudioStream (client, stream_flags,
+      devicep_frames, format, NULL);
+  HR_FAILED_RET (hr, IAudioClient3::InitializeSharedAudioStream, FALSE);
+
+  hr = IAudioClient3_GetCurrentSharedModeEnginePeriod (client, &tmpf,
+      &devicep_frames);
+  CoTaskMemFree (tmpf);
+  HR_FAILED_RET (hr, IAudioClient3::GetCurrentSharedModeEnginePeriod, FALSE);
+
+  *ret_devicep_frames = devicep_frames;
+  return TRUE;
+}