qgstreameraudiooutput.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 <common/qgstreameraudiooutput_p.h>
#include <audio/qgstreameraudiodevice_p.h>
 
#include <QtMultimedia/qaudiodevice.h>
#include <QtMultimedia/qaudiooutput.h>
#include <QtCore/qloggingcategory.h>
 
#include <utility>
 
static Q_LOGGING_CATEGORY(qLcMediaAudioOutput, "qt.multimedia.audiooutput")
 
QT_BEGIN_NAMESPACE
 
QMaybe<QPlatformAudioOutput *> QGstreamerAudioOutput::create(QAudioOutput *parent)
{
    QGstElement audioconvert = QGstElement::createFromFactory("audioconvert", "audioConvert");
    if (!audioconvert)
        return errorMessageCannotFindElement("audioconvert");
 
    QGstElement audioresample = QGstElement::createFromFactory("audioresample", "audioResample");
    if (!audioresample)
        return errorMessageCannotFindElement("audioresample");
 
    QGstElement volume = QGstElement::createFromFactory("volume", "volume");
    if (!volume)
        return errorMessageCannotFindElement("volume");
 
    QGstElement autoaudiosink = QGstElement::createFromFactory("autoaudiosink", "autoAudioSink");
    if (!autoaudiosink)
        return errorMessageCannotFindElement("autoaudiosink");
 
    return new QGstreamerAudioOutput(audioconvert, audioresample, volume, autoaudiosink, parent);
}
 
QGstreamerAudioOutput::QGstreamerAudioOutput(QGstElement audioconvert, QGstElement audioresample,
                                             QGstElement volume, QGstElement autoaudiosink,
                                             QAudioOutput *parent)
    : QObject(parent),
      QPlatformAudioOutput(parent),
      gstAudioOutput(QGstBin::create("audioOutput")),
      audioConvert(std::move(audioconvert)),
      audioResample(std::move(audioresample)),
      audioVolume(std::move(volume)),
      audioSink(std::move(autoaudiosink))
{
    audioQueue = QGstElement::createFromFactory("queue", "audioQueue");
    gstAudioOutput.add(audioQueue, audioConvert, audioResample, audioVolume, audioSink);
    qLinkGstElements(audioQueue, audioConvert, audioResample, audioVolume, audioSink);
 
    gstAudioOutput.addGhostPad(audioQueue, "sink");
}
 
QGstElement QGstreamerAudioOutput::createGstElement()
{
    const auto *customDeviceInfo =
            dynamic_cast<const QGStreamerCustomAudioDeviceInfo *>(m_audioOutput.handle());
 
    if (customDeviceInfo) {
        qCDebug(qLcMediaAudioOutput)
                << "requesting custom audio sink element: " << customDeviceInfo->id;
 
        QGstElement element =
                QGstBin::createFromPipelineDescription(customDeviceInfo->id, /*name=*/nullptr,
                                                       /*ghostUnlinkedPads=*/true);
        if (element)
            return element;
 
        qCWarning(qLcMediaAudioOutput)
                << "Cannot create audio sink element:" << customDeviceInfo->id;
    }
 
    const QByteArray &id = m_audioOutput.id();
    if constexpr (QT_CONFIG(pulseaudio)) {
        QGstElement newSink = QGstElement::createFromFactory("pulsesink", "audiosink");
        if (newSink) {
            newSink.set("device", id.constData());
            return newSink;
        } else {
            qWarning() << "Cannot create pulsesink";
        }
    } else if constexpr (QT_CONFIG(alsa)) {
        QGstElement newSink = QGstElement::createFromFactory("alsasink", "audiosink");
        if (newSink) {
            newSink.set("device", id.constData());
            return newSink;
        } else {
            qWarning() << "Cannot create alsasink";
        }
    } else {
        auto *deviceInfo = dynamic_cast<const QGStreamerAudioDeviceInfo *>(m_audioOutput.handle());
        if (deviceInfo && deviceInfo->gstDevice) {
            QGstElement element = QGstElement::createFromDevice(deviceInfo->gstDevice, "audiosink");
            if (element)
                return element;
        }
    }
    qCWarning(qLcMediaAudioOutput) << "Invalid audio device:" << m_audioOutput.id();
    qCWarning(qLcMediaAudioOutput)
            << "Failed to create a gst element for the audio device, using a default audio sink";
    return QGstElement::createFromFactory("autoaudiosink", "audiosink");
}
 
QGstreamerAudioOutput::~QGstreamerAudioOutput()
{
    gstAudioOutput.setStateSync(GST_STATE_NULL);
}
 
void QGstreamerAudioOutput::setVolume(float volume)
{
    audioVolume.set("volume", volume);
}
 
void QGstreamerAudioOutput::setMuted(bool muted)
{
    audioVolume.set("mute", muted);
}
 
void QGstreamerAudioOutput::setAudioDevice(const QAudioDevice &info)
{
    if (info == m_audioOutput)
        return;
    qCDebug(qLcMediaAudioOutput) << "setAudioOutput" << info.description() << info.isNull();
 
    m_audioOutput = info;
 
    QGstElement newSink = createGstElement();
 
    QGstPipeline::modifyPipelineWhileNotRunning(gstAudioOutput.getPipeline(), [&] {
        qUnlinkGstElements(audioVolume, audioSink);
        gstAudioOutput.stopAndRemoveElements(audioSink);
        audioSink = std::move(newSink);
        gstAudioOutput.add(audioSink);
        audioSink.syncStateWithParent();
        qLinkGstElements(audioVolume, audioSink);
    });
}
 
QT_END_NAMESPACE