1 files changed, 112 insertions, 0 deletions
diff --git a/src/multimedia/darwin/qmacosaudiodatautils_p.h b/src/multimedia/darwin/qmacosaudiodatautils_p.h
new file mode 100644
index 000000000..8cc2f8440
--- /dev/null
+++ b/src/multimedia/darwin/qmacosaudiodatautils_p.h
@@ -0,0 +1,112 @@
+// Copyright (C) 2021 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QMACOSAUDIODATAUTILS_P_H
+#define QMACOSAUDIODATAUTILS_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <CoreAudio/AudioHardware.h>
+
+#include "qaudiodevice.h"
+#include "qdebug.h"
+
+#include <optional>
+#include <vector>
+#include <algorithm>
+
+QT_BEGIN_NAMESPACE
+
+template<typename... Args>
+void printUnableToReadWarning(const char *logName, AudioObjectID objectID, const AudioObjectPropertyAddress &address, Args &&...args)
+{
+    if (!logName)
+        return;
+
+    char scope[5] = {0};
+    memcpy(&scope, &address.mScope, 4);
+    std::reverse(scope, scope + 4);
+
+    auto warn = qWarning();
+    warn << "Unable to read property" << logName << "for object" << objectID << ", scope" << scope << ";";
+    (warn << ... << args);
+    warn << "\n  If the warning is unexpected use test_audio_config to get comprehensive audio info and report a bug";
+}
+
+inline static AudioObjectPropertyAddress
+makePropertyAddress(AudioObjectPropertySelector selector, QAudioDevice::Mode mode,
+                    AudioObjectPropertyElement element = kAudioObjectPropertyElementMain)
+{
+    return { selector,
+             mode == QAudioDevice::Input ? kAudioDevicePropertyScopeInput
+                                         : kAudioDevicePropertyScopeOutput,
+             element };
+}
+
+inline static bool getAudioData(AudioObjectID objectID, const AudioObjectPropertyAddress &address,
+                                void *dst, UInt32 dstSize, const char *logName)
+{
+    UInt32 readBytes = dstSize;
+    const auto res = AudioObjectGetPropertyData(objectID, &address, 0, nullptr, &readBytes, dst);
+
+    if (res != noErr)
+        printUnableToReadWarning(logName, objectID, address, "Err:", res);
+    else if (readBytes != dstSize)
+        printUnableToReadWarning(logName, objectID, address, "Data size", readBytes, "VS", dstSize,
+                                 "expected");
+    else
+        return true;
+
+    return false;
+}
+
+template<typename T>
+std::optional<std::vector<T>> getAudioData(AudioObjectID objectID,
+                                           const AudioObjectPropertyAddress &address,
+                                           const char *logName, size_t minDataSize = 0)
+{
+    static_assert(std::is_trivial_v<T>, "A trivial type is expected");
+
+    UInt32 size = 0;
+    const auto res = AudioObjectGetPropertyDataSize(objectID, &address, 0, nullptr, &size);
+
+    if (res != noErr) {
+        printUnableToReadWarning(logName, objectID, address,
+                                 "AudioObjectGetPropertyDataSize failed, Err:", res);
+    } else if (size / sizeof(T) < minDataSize) {
+        printUnableToReadWarning(logName, objectID, address, "Data size is too small:", size, "VS",
+                                 minDataSize * sizeof(T), "bytes");
+    } else {
+        std::vector<T> data(size / sizeof(T));
+        if (getAudioData(objectID, address, data.data(), data.size() * sizeof(T), logName))
+            return { std::move(data) };
+    }
+
+    return {};
+}
+
+template<typename T>
+std::optional<T> getAudioObject(AudioObjectID objectID, const AudioObjectPropertyAddress &address,
+                                const char *logName)
+{
+    static_assert(std::is_trivial_v<T>, "A trivial type is expected");
+
+    T object{};
+    if (getAudioData(objectID, address, &object, sizeof(T), logName))
+        return { object };
+
+    return {};
+}
+
+QT_END_NAMESPACE
+
+#endif // QMACOSAUDIODATAUTILS_P_H