qwindowsaudiodevice.cpp

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// Copyright (C) 2016 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 "qwindowsaudiodevice_p.h"
 
#include <QtCore/qdebug.h>
#include <QtCore/qloggingcategory.h>
#include <QtCore/qthreadpool.h>
#include <QtCore/qt_windows.h>
#include <QtCore/private/qsystemerror_p.h>
#include <QtCore/qapplicationstatic.h>
 
#include <QtMultimedia/private/qaudioformat_p.h>
#include <QtMultimedia/private/qcominitializer_p.h>
#include <QtMultimedia/private/qcomtaskresource_p.h>
#include <QtMultimedia/private/qwindows_propertystore_p.h>
#include <QtMultimedia/private/qwindowsaudioutils_p.h>
 
#include <audioclient.h>
#include <mmdeviceapi.h>
#include <propkeydef.h>
 
#include <future>
#include <set>
 
QT_BEGIN_NAMESPACE
 
using QtMultimediaPrivate::PropertyStoreHelper;
using namespace Qt::Literals;
 
namespace {
 
Q_STATIC_LOGGING_CATEGORY(qLcAudioDeviceProbes, "qt.multimedia.audiodevice.probes")
 
std::optional<EndpointFormFactor> inferFormFactor(PropertyStoreHelper &propertyStore)
{
    std::optional<uint32_t> val = propertyStore.getUInt32(PKEY_AudioEndpoint_FormFactor);
    if (val == EndpointFormFactor::UnknownFormFactor)
        return EndpointFormFactor(*val);
 
    return std::nullopt;
}
 
std::optional<QAudioFormat::ChannelConfig>
inferChannelConfiguration(PropertyStoreHelper &propertyStore, int maximumChannelCount)
{
    std::optional<uint32_t> val = propertyStore.getUInt32(PKEY_AudioEndpoint_PhysicalSpeakers);
    if (val && val != 0)
        return QWindowsAudioUtils::maskToChannelConfig(*val, maximumChannelCount);
 
    return std::nullopt;
}
 
int maxChannelCountForFormFactor(EndpointFormFactor formFactor)
{
    switch (formFactor) {
    case EndpointFormFactor::Headphones:
    case EndpointFormFactor::Headset:
        return 2;
    case EndpointFormFactor::SPDIF:
        return 6; // SPDIF can have 2 channels of uncompressed or 6 channels of compressed audio
 
    case EndpointFormFactor::DigitalAudioDisplayDevice:
        return 8; // HDMI can have max 8 channels
 
    case EndpointFormFactor::Microphone:
        return 32; // 32 channels should be more than enough for real-world microphones
 
    default:
        return 128;
    }
}
 
struct FormatProbeResult
{
    void update(const QAudioFormat &fmt)
    {
        supportedSampleFormats.insert(fmt.sampleFormat());
        updateChannelCount(fmt.channelCount());
        updateSamplingRate(fmt.sampleRate());
    }
 
    void updateChannelCount(int channelCount)
    {
        if (channelCount < channelCountRange.first)
            channelCountRange.first = channelCount;
        if (channelCount > channelCountRange.second)
            channelCountRange.second = channelCount;
    }
 
    void updateSamplingRate(int samplingRate)
    {
        if (samplingRate < sampleRateRange.first)
            sampleRateRange.first = samplingRate;
        if (samplingRate > sampleRateRange.second)
            sampleRateRange.second = samplingRate;
    }
 
    std::set<QAudioFormat::SampleFormat> supportedSampleFormats;
    std::pair<int, int> channelCountRange{ std::numeric_limits<int>::max(), 0 };
    std::pair<int, int> sampleRateRange{ std::numeric_limits<int>::max(), 0 };
 
    [[maybe_unused]]
    friend QDebug operator<<(QDebug dbg, const FormatProbeResult &self)
    {
        QDebugStateSaver saver(dbg);
        dbg.nospace();
 
        dbg << "FormatProbeResult{supportedSampleFormats: " << self.supportedSampleFormats
            << ", channelCountRange: " << self.channelCountRange.first << " - " << self.channelCountRange.second
            << ", sampleRateRange: " << self.sampleRateRange.first << "-" << self.sampleRateRange.second
            << "}";
        return dbg;
    }
};
 
std::optional<QAudioFormat> performIsFormatSupportedWithClosestMatch(const ComPtr<IAudioClient> &audioClient,
                                                                     const QAudioFormat &fmt)
{
    using namespace QWindowsAudioUtils;
    std::optional<WAVEFORMATEXTENSIBLE> formatEx = toWaveFormatExtensible(fmt);
    if (!formatEx) {
        qCWarning(qLcAudioDeviceProbes) << "toWaveFormatExtensible failed" << fmt;
        return std::nullopt;
    }
 
    qCDebug(qLcAudioDeviceProbes) << "performIsFormatSupportedWithClosestMatch for" << fmt;
    QComTaskResource<WAVEFORMATEX> closestMatch;
    HRESULT result = audioClient->IsFormatSupported(AUDCLNT_SHAREMODE_SHARED, &formatEx->Format,
                                                    closestMatch.address());
 
    if (FAILED(result)) {
        qCDebug(qLcAudioDeviceProbes) << "performIsFormatSupportedWithClosestMatch: error" << QSystemError::windowsComString(result);
        return std::nullopt;
    }
 
    if (closestMatch) {
        QAudioFormat closestMatchFormat = waveFormatExToFormat(*closestMatch);
        qCDebug(qLcAudioDeviceProbes) << "performProbe returned closest match" << closestMatchFormat;
        return closestMatchFormat;
    }
 
    qCDebug(qLcAudioDeviceProbes) << "performProbe successful";
 
    return fmt;
}
 
std::optional<FormatProbeResult> probeFormats(const ComPtr<IAudioClient> &audioClient,
                                              PropertyStoreHelper &propertyStore,
                                              const QAudioFormat &preferredFormat)
{
    using namespace QWindowsAudioUtils;
 
    // probing formats is a bit slow, so we limit the number of channels of we can
    std::optional<EndpointFormFactor> formFactor = inferFormFactor(propertyStore);
    int maxChannelsForFormFactor = formFactor ? maxChannelCountForFormFactor(*formFactor) : 128;
 
    qCDebug(qLcAudioDeviceProbes) << "probing: maxChannelsForFormFactor" << maxChannelsForFormFactor << formFactor;
 
    std::optional<FormatProbeResult> limits;
 
    // Note: probing for AUDCLNT_SHAREMODE_SHARED, float32 seems to be the preferred format for all
    // devices.
    constexpr QAudioFormat::SampleFormat initialSampleFormat = QAudioFormat::SampleFormat::Float;
 
    // we initially probe for the maximum channel count for the format.
    // wasapi will typically recommend a "closest" match, containing the max number of channels
    // we can probe for.
    QAudioFormat initialProbeFormat;
    initialProbeFormat.setSampleFormat(initialSampleFormat);
    initialProbeFormat.setSampleRate(preferredFormat.sampleRate());
    initialProbeFormat.setChannelCount(maxChannelsForFormFactor);
 
    qCDebug(qLcAudioDeviceProbes) << "probeFormats: probing for" << initialProbeFormat;
 
    std::optional<QAudioFormat> initialProbeResult =
            performIsFormatSupportedWithClosestMatch(audioClient, initialProbeFormat);
 
    int maxChannelForFormat;
    if (initialProbeResult) {
        if (initialProbeResult->sampleRate() != preferredFormat.sampleRate()) {
            qCDebug(qLcAudioDeviceProbes)
                    << "probing: returned a different sample rate as closest match ..."
                    << *initialProbeResult;
            return std::nullopt;
        }
 
        maxChannelForFormat = initialProbeResult->channelCount();
    } else {
        // some drivers seem to not report any closest match, but simply fail.
        // in this case we need to brute-force enumerate the formats
        // however probing is rather expensive, so we limit our probes to a maxmimum of 2
        // channels
        maxChannelForFormat = std::min(maxChannelsForFormFactor, 2);
    }
 
    // we rely on wasapi's AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM for format conversion, so we only
    // need to check the closest match format
    QAudioFormat::SampleFormat probeSampleFormat =
            initialProbeResult ? initialProbeResult->sampleFormat() : initialSampleFormat;
 
    for (int channelCount = 1; channelCount != maxChannelForFormat + 1; ++channelCount) {
        QAudioFormat fmt;
        fmt.setSampleFormat(probeSampleFormat);
        fmt.setSampleRate(preferredFormat.sampleRate());
        fmt.setChannelCount(channelCount);
 
        std::optional<WAVEFORMATEXTENSIBLE> formatEx = toWaveFormatExtensible(fmt);
        if (!formatEx)
            continue;
 
        qCDebug(qLcAudioDeviceProbes) << "probing" << fmt;
 
        QComTaskResource<WAVEFORMATEX> closestMatch;
        HRESULT result = audioClient->IsFormatSupported(AUDCLNT_SHAREMODE_SHARED, &formatEx->Format,
                                                        closestMatch.address());
 
        if (FAILED(result)) {
            qCDebug(qLcAudioDeviceProbes)
                    << "probing format failed" << QSystemError::windowsComString(result);
            continue;
        }
 
        if (closestMatch) {
            qCDebug(qLcAudioDeviceProbes) << "probing format reported a closest match"
                                          << waveFormatExToFormat(*closestMatch);
            continue; // we don't have an exact match, but just something close by
        }
 
        if (!limits)
            limits = FormatProbeResult{};
 
        qCDebug(qLcAudioDeviceProbes) << "probing format successful" << fmt;
        limits->update(fmt);
    }
 
    qCDebug(qLcAudioDeviceProbes) << "probing successful" << limits;
 
    return limits;
}
 
std::optional<QAudioFormat> probePreferredFormat(const ComPtr<IAudioClient> &audioClient)
{
    using namespace QWindowsAudioUtils;
 
    static const QAudioFormat preferredFormat = [] {
        QAudioFormat fmt;
        fmt.setSampleRate(44100);
        fmt.setChannelCount(2);
        fmt.setSampleFormat(QAudioFormat::Int16);
        return fmt;
    }();
 
    std::optional<WAVEFORMATEXTENSIBLE> formatEx = toWaveFormatExtensible(preferredFormat);
    if (!formatEx)
        return std::nullopt;
 
    QComTaskResource<WAVEFORMATEX> closestMatch;
    HRESULT result = audioClient->IsFormatSupported(AUDCLNT_SHAREMODE_SHARED, &formatEx->Format,
                                                    closestMatch.address());
 
    if (FAILED(result))
        return std::nullopt;
    if (!closestMatch)
        return preferredFormat;
 
    QAudioFormat closestMatchFormat = waveFormatExToFormat(*closestMatch);
    if (closestMatchFormat.isValid())
        return closestMatchFormat;
    return std::nullopt;
}
 
struct WindowsFormatResult
{
    QAudioDevicePrivate::AudioDeviceFormat format;
    QtWASAPI::WindowsProbeData probeData;
};
 
WindowsFormatResult performFormatProbe(ComPtr<IMMDevice> immDev)
{
    QAudioDevicePrivate::AudioDeviceFormat format;
    QtWASAPI::WindowsProbeData probeData{
        { 1, 2 },
        { QtMultimediaPrivate::allSupportedSampleRates.front(),
          QtMultimediaPrivate::allSupportedSampleRates.back() },
    };
 
    ComPtr<IAudioClient> audioClient;
    HRESULT hr = immDev->Activate(__uuidof(IAudioClient), CLSCTX_INPROC_SERVER, nullptr,
                                  reinterpret_cast<void **>(audioClient.GetAddressOf()));
 
    if (SUCCEEDED(hr)) {
        QComTaskResource<WAVEFORMATEX> mixFormat;
        hr = audioClient->GetMixFormat(mixFormat.address());
        if (SUCCEEDED(hr))
            format.preferredFormat = QWindowsAudioUtils::waveFormatExToFormat(*mixFormat);
    } else {
        qWarning() << "QWindowsAudioDeviceInfo: could not activate audio client:"
                   << QSystemError::windowsComString(hr);
        return {format, probeData};
    }
 
    auto propStoreHelper = PropertyStoreHelper::open(immDev);
    if (!propStoreHelper) {
        qWarning() << "QWindowsAudioDeviceInfo: could not open property store:"
                   << propStoreHelper.error();
        return {format, probeData};
    }
 
    qCDebug(qLcAudioDeviceProbes) << "probing formats";
 
    std::optional<FormatProbeResult> probedFormats =
            probeFormats(audioClient, *propStoreHelper, format.preferredFormat);
    if (probedFormats) {
        // wasapi does sample format conversion for us: AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM
        format.supportedSampleFormats = qAllSupportedSampleFormats();
 
        // this is a bit of a lie:
        // for sources, WASAPI only supports a single sample rate, but we inject a resampler
        // for sinks, WASAPI resamples internally
        format.minimumSampleRate = QtMultimediaPrivate::allSupportedSampleRates.front();
        format.maximumSampleRate = QtMultimediaPrivate::allSupportedSampleRates.back();
 
        format.minimumChannelCount = 1; // we are lying here, but expect the QWASAPIAudioSinkStream to
                                        // perform format conversion
        format.maximumChannelCount = probedFormats->channelCountRange.second;
 
        probeData.channelCountRange = probedFormats->channelCountRange;
        probeData.sampleRateRange = probedFormats->sampleRateRange;
    }
 
    if (!format.preferredFormat.isValid()) {
        std::optional<QAudioFormat> probedFormat = probePreferredFormat(audioClient);
        if (probedFormat)
            format.preferredFormat = *probedFormat;
    }
 
    std::optional<QAudioFormat::ChannelConfig> config =
            inferChannelConfiguration(*propStoreHelper, format.maximumChannelCount);
 
    format.channelConfiguration = config
            ? *config
            : QAudioFormat::defaultChannelConfigForChannelCount(format.maximumChannelCount);
 
    return {format, probeData};
}
 
struct WasapiProbeThreadpool final : public QThreadPool
{
    WasapiProbeThreadpool()
    {
        setObjectName(u"WasapiProbeThreadpool"_s);
        setMaxThreadCount(2);
        setThreadPriority(QThread::LowPriority);
        setServiceLevel(QThread::QualityOfService::Eco);
        setExpiryTimeout(500 /*ms*/);
    }
 
    ~WasapiProbeThreadpool()
    {
        // Ensure all threads submitted tasks are canceled before destruction
        clear();
    }
};
 
Q_APPLICATION_STATIC(WasapiProbeThreadpool, wasapiProbeThreadpool)
 
QtWASAPI::WindowsFormatResultFutures probeWindowsAudioDeviceFormatAsync(ComPtr<IMMDevice> immDev)
{
    std::promise<QAudioDevicePrivate::AudioDeviceFormat> formatPromise;
    std::promise<QtWASAPI::WindowsProbeData> probePromise;
 
    QtWASAPI::WindowsFormatResultFutures ret{
        formatPromise.get_future(),
        probePromise.get_future(),
    };
 
    wasapiProbeThreadpool->start([immDev = std::move(immDev),
                                  formatPromise = std::move(formatPromise),
                                  probePromise = std::move(probePromise)]() mutable {
        auto result = performFormatProbe(immDev);
        formatPromise.set_value(result.format);
        probePromise.set_value(result.probeData);
    });
 
    return ret;
}
 
} // namespace
 
QWindowsAudioDevice::QWindowsAudioDevice(QByteArray id, ComPtr<IMMDevice> immDev, QString desc,
                                         QUuid containerId, EndpointFormFactor formFactor,
                                         QAudioDevice::Mode mode)
    : QWindowsAudioDevice{ std::move(id), std::move(desc),
                           containerId,   formFactor,
                           mode,          probeWindowsAudioDeviceFormatAsync(std::move(immDev)) }
{}
 
QWindowsAudioDevice::QWindowsAudioDevice(QByteArray deviceId, QString description,
                                         QUuid containerId, EndpointFormFactor formFactor,
                                         QAudioDevice::Mode mode,
                                         QtWASAPI::WindowsFormatResultFutures result)
    : QAudioDevicePrivate(std::move(deviceId), mode, std::move(description), false,
                          std::move(result.formatFuture)),
      m_device_ContainerId{
          containerId,
      },
      m_formFactor{
          formFactor,
      },
      m_probeDataFuture{
          result.probeDataFuture.share(),
      }
{
}
 
ComPtr<IMMDevice> QWindowsAudioDevice::open() const
{
    QComInitializer init;
    ComPtr<IMMDeviceEnumerator> deviceEnumerator;
    HRESULT hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), nullptr, CLSCTX_ALL,
                                  IID_PPV_ARGS(&deviceEnumerator));
    if (FAILED(hr)) {
        qWarning() << "Failed to create device enumerator" << hr;
        return nullptr;
    }
 
    auto deviceId = QString::fromUtf8(id);
 
    ComPtr<IMMDevice> device;
    HRESULT result =
            deviceEnumerator->GetDevice(deviceId.toStdWString().c_str(), device.GetAddressOf());
    if (FAILED(result)) {
        qWarning() << "IMMDeviceEnumerator::GetDevice failed" << id
                   << QSystemError::windowsComString(result);
        return nullptr;
    }
    return device;
}
 
QWindowsAudioDevice::~QWindowsAudioDevice() = default;
 
std::unique_ptr<QAudioDevicePrivate> QWindowsAudioDevice::clone() const
{
    return std::unique_ptr<QAudioDevicePrivate>(new QWindowsAudioDevice{ *this });
}
 
QT_END_NAMESPACE