path: root/src/multimedia/windows/qwindowsmediadevices.cpp

// 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 "qwindowsmediadevices_p.h"
#include "qmediadevices.h"
#include "qvarlengtharray.h"

#include "qwindowsaudiosource_p.h"
#include "qwindowsaudiosink_p.h"
#include "qwindowsaudiodevice_p.h"

#include <mmsystem.h>
#include <mmddk.h>
#include <mfobjects.h>
#include <mfidl.h>
#include <Mferror.h>
#include <mmdeviceapi.h>
#include <qwindowsmfdefs_p.h>

#include <QtCore/qmap.h>

QT_BEGIN_NAMESPACE

class CMMNotificationClient : public IMMNotificationClient
{
    LONG m_cRef;
    QWindowsIUPointer<IMMDeviceEnumerator> m_enumerator;
    QWindowsMediaDevices *m_windowsMediaDevices;
    QMap<QString, DWORD> m_deviceState;

public:
    CMMNotificationClient(QWindowsMediaDevices *windowsMediaDevices,
                          QWindowsIUPointer<IMMDeviceEnumerator> enumerator,
                          QMap<QString, DWORD> &&deviceState) :
        m_cRef(1),
        m_enumerator(enumerator),
        m_windowsMediaDevices(windowsMediaDevices),
        m_deviceState(deviceState)
    {}

    virtual ~CMMNotificationClient() {}

    // IUnknown methods -- AddRef, Release, and QueryInterface
    ULONG STDMETHODCALLTYPE AddRef() override
    {
        return InterlockedIncrement(&m_cRef);
    }

    ULONG STDMETHODCALLTYPE Release() override
    {
        ULONG ulRef = InterlockedDecrement(&m_cRef);
        if (0 == ulRef) {
            delete this;
        }
        return ulRef;
    }

    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, VOID **ppvInterface) override
    {
        if (IID_IUnknown == riid) {
            AddRef();
            *ppvInterface = (IUnknown*)this;
        } else if (__uuidof(IMMNotificationClient) == riid) {
            AddRef();
            *ppvInterface = (IMMNotificationClient*)this;
        } else {
            *ppvInterface = NULL;
            return E_NOINTERFACE;
        }
        return S_OK;
    }

    HRESULT STDMETHODCALLTYPE OnDefaultDeviceChanged(EDataFlow flow, ERole role, LPCWSTR) override
    {
        if (role == ERole::eMultimedia)
            emitAudioDevicesChanged(flow);

        return S_OK;
    }

    HRESULT STDMETHODCALLTYPE OnDeviceAdded(LPCWSTR deviceID) override
    {
        auto it = m_deviceState.find(QString::fromWCharArray(deviceID));
        if (it == std::end(m_deviceState)) {
            m_deviceState.insert(QString::fromWCharArray(deviceID), DEVICE_STATE_ACTIVE);
            emitAudioDevicesChanged(deviceID);
        }

        return S_OK;
    };

    HRESULT STDMETHODCALLTYPE OnDeviceRemoved(LPCWSTR deviceID) override
    {
        auto key = QString::fromWCharArray(deviceID);
        auto it = m_deviceState.find(key);
        if (it != std::end(m_deviceState)) {
            if (it.value() == DEVICE_STATE_ACTIVE)
                emitAudioDevicesChanged(deviceID);
            m_deviceState.remove(key);
        }

        return S_OK;
    }

    HRESULT STDMETHODCALLTYPE OnDeviceStateChanged(LPCWSTR deviceID, DWORD newState) override
    {
        if (auto it = m_deviceState.find(QString::fromWCharArray(deviceID)); it != std::end(m_deviceState)) {
            // If either the old state or the new state is active emit device change
            if ((it.value() == DEVICE_STATE_ACTIVE) != (newState == DEVICE_STATE_ACTIVE)) {
                emitAudioDevicesChanged(deviceID);
            }
            it.value() = newState;
        }

        return S_OK;
    }

    HRESULT STDMETHODCALLTYPE OnPropertyValueChanged(LPCWSTR, const PROPERTYKEY) override
    {
        return S_OK;
    }

    void emitAudioDevicesChanged(EDataFlow flow)
    {
        // windowsMediaDevice may be deleted as we are executing the callback
        if (flow == EDataFlow::eCapture) {
            m_windowsMediaDevices->audioInputsChanged();
        } else if (flow == EDataFlow::eRender) {
            m_windowsMediaDevices->audioOutputsChanged();
        }
    }

    void emitAudioDevicesChanged(LPCWSTR deviceID)
    {
        QWindowsIUPointer<IMMDevice> device;
        QWindowsIUPointer<IMMEndpoint> endpoint;
        EDataFlow flow;

        if (SUCCEEDED(m_enumerator->GetDevice(deviceID, device.address()))
            && SUCCEEDED(device->QueryInterface(__uuidof(IMMEndpoint), (void**)endpoint.address()))
            && SUCCEEDED(endpoint->GetDataFlow(&flow)))
        {
                    emitAudioDevicesChanged(flow);
        }
    }
};

QWindowsMediaDevices::QWindowsMediaDevices()
    : QPlatformMediaDevices()
{
    CoInitialize(nullptr);

    auto hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), nullptr,
                CLSCTX_INPROC_SERVER,__uuidof(IMMDeviceEnumerator),
                (void**)&m_deviceEnumerator);

    if (SUCCEEDED(hr)) {
        QMap<QString, DWORD> devState;
        QWindowsIUPointer<IMMDeviceCollection> devColl;
        UINT count = 0;

        if (SUCCEEDED(m_deviceEnumerator->EnumAudioEndpoints(EDataFlow::eAll, DEVICE_STATEMASK_ALL, devColl.address()))
            && SUCCEEDED(devColl->GetCount(&count)))
        {
            for (UINT i = 0; i < count; i++) {
                QWindowsIUPointer<IMMDevice> device;
                DWORD state = 0;
                LPWSTR id = nullptr;

                if (SUCCEEDED(devColl->Item(i, device.address()))
                    && SUCCEEDED(device->GetState(&state))
                    && SUCCEEDED(device->GetId(&id)))
                {
                    devState.insert(QString::fromWCharArray(id), state);
                    CoTaskMemFree(id);
                }
            }
        }


        m_notificationClient.reset(new CMMNotificationClient(this, m_deviceEnumerator, std::move(devState)));
        m_deviceEnumerator->RegisterEndpointNotificationCallback(m_notificationClient.get());

    } else {
        qWarning() << "Audio device change notification disabled";
    }
}

QWindowsMediaDevices::~QWindowsMediaDevices()
{
    if (m_deviceEnumerator) {
        m_deviceEnumerator->UnregisterEndpointNotificationCallback(m_notificationClient.get());
    }

    m_deviceEnumerator.reset();
    m_notificationClient.reset();

    CoUninitialize();
}

QList<QAudioDevice> QWindowsMediaDevices::availableDevices(QAudioDevice::Mode mode) const
{
    const auto audioOut = mode == QAudioDevice::Output;

    const auto defaultAudioDeviceID = [this, audioOut]{
        const auto dataFlow = audioOut ? EDataFlow::eRender : EDataFlow::eCapture;
        QWindowsIUPointer<IMMDevice> dev;
        LPWSTR id = nullptr;
        QString sid;

        if (SUCCEEDED(m_deviceEnumerator->GetDefaultAudioEndpoint(dataFlow, ERole::eMultimedia, dev.address()))
            && SUCCEEDED(dev->GetId(&id))) {
            sid = QString::fromWCharArray(id);
            CoTaskMemFree(id);
        }
        return sid.toUtf8();
    }();

    QList<QAudioDevice> devices;

    auto waveDevices = audioOut ? waveOutGetNumDevs() : waveInGetNumDevs();

    for (auto waveID = 0u; waveID < waveDevices; waveID++) {
        auto wave = IntToPtr(waveID);
        auto waveMessage = [wave, audioOut](UINT msg, auto p0, auto p1) {
            return audioOut ? waveOutMessage((HWAVEOUT)wave, msg, (DWORD_PTR)p0, (DWORD_PTR)p1)
                            : waveInMessage((HWAVEIN)wave, msg, (DWORD_PTR)p0, (DWORD_PTR)p1);
        };

        size_t len = 0;
        if (waveMessage(DRV_QUERYFUNCTIONINSTANCEIDSIZE, &len, 0) != MMSYSERR_NOERROR)
            continue;

        QVarLengthArray<WCHAR> id(len);
        if (waveMessage(DRV_QUERYFUNCTIONINSTANCEID, id.data(), len) != MMSYSERR_NOERROR)
            continue;

        QWindowsIUPointer<IMMDevice> device;
        QWindowsIUPointer<IPropertyStore> props;
        if (FAILED(m_deviceEnumerator->GetDevice(id.data(), device.address()))
            || FAILED(device->OpenPropertyStore(STGM_READ, props.address()))) {
            continue;
        }

        PROPVARIANT varName;
        PropVariantInit(&varName);

        if (SUCCEEDED(props->GetValue(QMM_PKEY_Device_FriendlyName, &varName))) {
            auto description = QString::fromWCharArray(varName.pwszVal);
            auto strID = QString::fromWCharArray(id.data()).toUtf8();

            auto dev = new QWindowsAudioDeviceInfo(strID, device, waveID, description, mode);
            dev->isDefault = strID == defaultAudioDeviceID;

            devices.append(dev->create());
        }
        PropVariantClear(&varName);
    }

    return devices;
}

QList<QAudioDevice> QWindowsMediaDevices::audioInputs() const
{
    return availableDevices(QAudioDevice::Input);
}

QList<QAudioDevice> QWindowsMediaDevices::audioOutputs() const
{
    return availableDevices(QAudioDevice::Output);
}

QPlatformAudioSource *QWindowsMediaDevices::createAudioSource(const QAudioDevice &deviceInfo,
                                                              QObject *parent)
{
    const auto *devInfo = static_cast<const QWindowsAudioDeviceInfo *>(deviceInfo.handle());
    return new QWindowsAudioSource(devInfo->waveId(), parent);
}

QPlatformAudioSink *QWindowsMediaDevices::createAudioSink(const QAudioDevice &deviceInfo,
                                                          QObject *parent)
{
    const auto *devInfo = static_cast<const QWindowsAudioDeviceInfo *>(deviceInfo.handle());
    return new QWindowsAudioSink(devInfo->immDev(), parent);
}

QT_END_NAMESPACE