qandroidaudiodevices.cpp

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// 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
 
#include <QtMultimedia/private/qandroidaudiodevices_p.h>
 
#include <QtMultimedia/private/qandroidaudiodevice_p.h>
#include <QtMultimedia/private/qandroidaudiojnitypes_p.h>
#include <QtMultimedia/private/qandroidaudiosink_p.h>
#include <QtMultimedia/private/qandroidaudiosource_p.h>
 
#include <QtMultimedia/private/qplatformmediaintegration_p.h>
 
#include <QtCore/qjniobject.h>
 
QT_BEGIN_NAMESPACE
 
using namespace QtJniTypes;
 
namespace {
 
QAudioFormat preferredFormatForDevice(const QtJniTypes::AudioDeviceInfo &deviceInfo)
{
    QAudioFormat preferredFormat;
 
    // Set preferred channel count based on what device reports, with default set to stereo (2)
    QJniArray<jint> channelCounts = deviceInfo.callMethod<QJniArray<jint>>("getChannelCounts");
    if (channelCounts.isEmpty()) {
        preferredFormat.setChannelConfig(QAudioFormat::ChannelConfigStereo);
    } else {
        const auto [minIt, maxIt] = std::minmax_element(channelCounts.begin(), channelCounts.end());
        const int channelCount = std::clamp(2, *minIt, *maxIt);
        preferredFormat.setChannelConfig(
                QAudioFormat::defaultChannelConfigForChannelCount(channelCount));
    }
 
    // Get optimal sample rate from AudioManager
    preferredFormat.setSampleRate(
            QtAudioDeviceManager::callStaticMethod<jint>("getDefaultSampleRate"));
 
    // Using Float avoids conversions for processing, so we should prefer that instead of whatever
    // the device uses natively
    preferredFormat.setSampleFormat(QAudioFormat::Float);
 
    return preferredFormat;
};
 
QList<QAudioDevice> availableDevices(QAudioDevice::Mode mode)
{
    if (mode == QAudioDevice::Null)
        return {};
 
    QList<QAudioDevice> devices;
    const char *getMethod =
            mode == QAudioDevice::Input ? "getAudioInputDevices" : "getAudioOutputDevices";
    auto deviceInfos =
            QtAudioDeviceManager::callStaticMethod<QJniArray<AudioDeviceInfo>>(getMethod);
 
    if (!deviceInfos.isValid())
        return {};
 
    for (int i = 0; i < deviceInfos.size(); ++i) {
        AudioDeviceInfo deviceInfo = deviceInfos.at(i);
        int id = deviceInfo.callMethod<jint>("getId");
        jint deviceType = deviceInfo.callMethod<jint>("getType");
        auto description = QtAudioDeviceManager::callStaticMethod<QString>(
                "audioDeviceTypeToString", deviceType);
        bool isBluetoothDevice =
                QtAudioDeviceManager::callStaticMethod<jboolean>("isBluetoothDevice", deviceInfo);
        devices << QAudioDevicePrivate::createQAudioDevice(std::make_unique<QAndroidAudioDevice>(
                QString::number(id).toUtf8(), description, mode,
                preferredFormatForDevice(deviceInfo), isBluetoothDevice, i == 0));
    }
 
    return devices;
}
 
} // namespace
 
// Called by any C++ thread
QAndroidAudioDevices::QAndroidAudioDevices() : QPlatformAudioDevices()
{
    QtAudioDeviceManager::callStaticMethod<void>(
        "qAndroidAudioDevicesConstructed",
        static_cast<jlong>(reinterpret_cast<size_t>(this)));
}
 
QAndroidAudioDevices::~QAndroidAudioDevices()
{
    // Performs a blocking call to unregister QAndroidAudioDevices from receiving
    // any more callbacks, and flushes remaining callbacks.
    QtAudioDeviceManager::callStaticMethod<void>("qAndroidAudioDevicesDestroyed");
}
 
// Called by any C++ thread
QList<QAudioDevice> QAndroidAudioDevices::findAudioInputs() const
{
    return availableDevices(QAudioDevice::Input);
}
 
// Called by any C++ thread
QList<QAudioDevice> QAndroidAudioDevices::findAudioOutputs() const
{
    return availableDevices(QAudioDevice::Output);
}
 
// Called by any C++ thread
QPlatformAudioSource *QAndroidAudioDevices::createAudioSource(const QAudioDevice &deviceInfo,
                                                              const QAudioFormat &fmt,
                                                              QObject *parent)
{
    return new QtAAudio::QAndroidAudioSource(deviceInfo, fmt, parent);
}
 
// Called by any C++ thread
QPlatformAudioSink *QAndroidAudioDevices::createAudioSink(const QAudioDevice &deviceInfo,
                                                          const QAudioFormat &fmt, QObject *parent)
{
    return new QtAAudio::QAndroidAudioSink(deviceInfo, fmt, parent);
}
 
// Invoked by background Java Handler thread
static void onAudioInputDevicesUpdated(
    JNIEnv * /*env*/,
    jobject /*thiz*/,
    jlong nativePtr)
{
    auto *audioDevices = reinterpret_cast<QAndroidAudioDevices*>(static_cast<size_t>(nativePtr));
    Q_ASSERT(!audioDevices->thread()->isCurrentThread());
    audioDevices->onAudioInputsChanged();
}
Q_DECLARE_JNI_NATIVE_METHOD(onAudioInputDevicesUpdated)
 
// Invoked by background Java Handler thread
static void onAudioOutputDevicesUpdated(
    JNIEnv * /*env*/,
    jobject /*thiz*/,
    jlong nativePtr)
{
    auto *audioDevices = reinterpret_cast<QAndroidAudioDevices*>(static_cast<size_t>(nativePtr));
    Q_ASSERT(!audioDevices->thread()->isCurrentThread());
    audioDevices->onAudioOutputsChanged();
}
Q_DECLARE_JNI_NATIVE_METHOD(onAudioOutputDevicesUpdated)
 
bool QAndroidAudioDevices::registerNativeMethods()
{
    static const bool registered = []{
        const auto context = QNativeInterface::QAndroidApplication::context();
        QtAudioDeviceManager::callStaticMethod<void>("setContext", context);
 
        return QtJniTypes::QtAudioDeviceManager::registerNativeMethods({
            Q_JNI_NATIVE_METHOD(onAudioInputDevicesUpdated),
            Q_JNI_NATIVE_METHOD(onAudioOutputDevicesUpdated),
        });
    }();
    return registered;
}
 
QT_END_NAMESPACE
 
extern "C" Q_DECL_EXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void * /*reserved*/)
{
    static bool initialized = false;
    if (initialized)
        return JNI_VERSION_1_6;
    initialized = true;
 
    QT_USE_NAMESPACE
    typedef union {
        JNIEnv *nativeEnvironment;
        void *venv;
    } UnionJNIEnvToVoid;
 
    UnionJNIEnvToVoid uenv;
    uenv.venv = NULL;
 
    if (vm->GetEnv(&uenv.venv, JNI_VERSION_1_6) != JNI_OK)
        return JNI_ERR;
 
    if (!QAndroidAudioDevices::registerNativeMethods())
        return JNI_ERR;
 
    return JNI_VERSION_1_6;
}