Introduce MediaPlayer::videoOutput property

This property holds the target video output,
and allows to render video to multiple items.

    MediaPlayer {
        videoOutput: [videoOutput1, 1, "ignored", videoOutput2.videoSurface]
    }

Incorrect inputs are ignored.

The property also accepts single either QAbstractVideoSurface or QDeclarativeVideoOutput objects.

Task-number: QTBUG-32939
Change-Id: I41fc557dcac60be6d70b3889036ff4ae75734cc0
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

6 files changed, 136 insertions, 2 deletions

diff --git a/src/imports/multimedia/multimedia.cpp b/src/imports/multimedia/multimedia.cpp
index 6106bb45d..0bbe9cae3 100644
--- a/src/imports/multimedia/multimedia.cpp
+++ b/src/imports/multimedia/multimedia.cpp
@@ -162,6 +162,7 @@ public:
         qmlRegisterType<QDeclarativeVideoOutput, 13>(uri, 5, 13, "VideoOutput");
 
         // 5.15 types
+        qmlRegisterType<QDeclarativeAudio, 15>(uri, 5, 15, "MediaPlayer");
         qmlRegisterType<QDeclarativeVideoOutput, 15>(uri, 5, 15, "VideoOutput");
         qmlRegisterType<QAbstractVideoSurface>();
 
diff --git a/src/imports/multimedia/qdeclarativeaudio.cpp b/src/imports/multimedia/qdeclarativeaudio.cpp
index 9d41c77fa..fcba6257d 100644
--- a/src/imports/multimedia/qdeclarativeaudio.cpp
+++ b/src/imports/multimedia/qdeclarativeaudio.cpp
@@ -45,12 +45,14 @@
 
 #include <qmediaservice.h>
 #include <private/qmediaserviceprovider_p.h>
+#include <private/qdeclarativevideooutput_p.h>
 #include <qmetadatareadercontrol.h>
 #include <qmediaavailabilitycontrol.h>
 
 #include "qdeclarativeplaylist_p.h"
 #include "qdeclarativemediametadata_p.h"
 
+#include <QAbstractVideoSurface>
 #include <QTimerEvent>
 #include <QtQml/qqmlengine.h>
 
@@ -130,6 +132,63 @@ QDeclarativeAudio::~QDeclarativeAudio()
 }
 
 /*!
+    \since 5.15
+    \qmlproperty url QtMultimedia::MediaPlayer::videoOutput
+
+    This property holds the target video output.
+    Accepts one or an array of QAbstractVideoSurface or VideoOutput elements.
+
+    \snippet multimedia-snippets/multiple-videooutputs.qml complete
+
+    \sa QMediaPlayer::setVideoOutput()
+*/
+
+QVariant QDeclarativeAudio::videoOutput() const
+{
+    return m_videoOutput;
+}
+
+void QDeclarativeAudio::setVideoOutput(const QVariant &v)
+{
+    if (m_videoOutput == v)
+        return;
+
+    QAbstractVideoSurface *surface = nullptr;
+    auto vo = v.value<QDeclarativeVideoOutput *>();
+    if (vo)
+        surface = vo->videoSurface();
+    else
+        surface = v.value<QAbstractVideoSurface *>();
+
+    // If only one object has been passed.
+    if (surface) {
+        m_player->setVideoOutput(surface);
+    } else {
+        QVector<QAbstractVideoSurface *> surfaces;
+        // Check if it is an array.
+        auto arr = v.value<QJSValue>();
+        if (!arr.isNull()) {
+            const int len = arr.property("length").toInt();
+            for (int i = 0; i < len; ++i) {
+                auto &&v = arr.property(i);
+                if (v.isQObject()) {
+                    auto obj = v.toQObject();
+                    vo = qobject_cast<QDeclarativeVideoOutput *>(obj);
+                    surface = vo ? vo->videoSurface() : qobject_cast<QAbstractVideoSurface *>(obj);
+                    if (surface)
+                        surfaces.append(surface);
+                }
+            }
+        }
+
+        m_player->setVideoOutput(surfaces);
+    }
+
+    m_videoOutput = v;
+    emit videoOutputChanged();
+}
+
+/*!
     \qmlproperty enumeration QtMultimedia::Audio::availability
 
     Returns the availability state of the media player.
diff --git a/src/imports/multimedia/qdeclarativeaudio_p.h b/src/imports/multimedia/qdeclarativeaudio_p.h
index 043b36042..dc8800695 100644
--- a/src/imports/multimedia/qdeclarativeaudio_p.h
+++ b/src/imports/multimedia/qdeclarativeaudio_p.h
@@ -97,6 +97,7 @@ class QDeclarativeAudio : public QObject, public QQmlParserStatus
     Q_PROPERTY(AudioRole audioRole READ audioRole WRITE setAudioRole NOTIFY audioRoleChanged REVISION 1)
     Q_PROPERTY(QString customAudioRole READ customAudioRole WRITE setCustomAudioRole NOTIFY customAudioRoleChanged REVISION 3)
     Q_PROPERTY(int notifyInterval READ notifyInterval WRITE setNotifyInterval NOTIFY notifyIntervalChanged REVISION 2)
+    Q_PROPERTY(QVariant videoOutput READ videoOutput WRITE setVideoOutput NOTIFY videoOutputChanged REVISION 15)
     Q_ENUMS(Status)
     Q_ENUMS(Error)
     Q_ENUMS(Loop)
@@ -164,6 +165,9 @@ public:
     QDeclarativeAudio(QObject *parent = 0);
     ~QDeclarativeAudio();
 
+    QVariant videoOutput() const;
+    void setVideoOutput(const QVariant &);
+
     bool hasAudio() const;
     bool hasVideo() const;
 
@@ -269,6 +273,7 @@ Q_SIGNALS:
 
     void mediaObjectChanged();
     Q_REVISION(2) void notifyIntervalChanged();
+    Q_REVISION(15) void videoOutputChanged();
 
 private Q_SLOTS:
     void _q_error(QMediaPlayer::Error);
@@ -305,6 +310,7 @@ private:
 
     QMediaPlayer *m_player;
     int m_notifyInterval;
+    QVariant m_videoOutput;
 
     friend class QDeclarativeMediaBaseAnimation;
 };
diff --git a/src/multimedia/doc/snippets/multimedia-snippets/multimedia-snippets.pro b/src/multimedia/doc/snippets/multimedia-snippets/multimedia-snippets.pro
index c13090a79..a46b20bd0 100644
--- a/src/multimedia/doc/snippets/multimedia-snippets/multimedia-snippets.pro
+++ b/src/multimedia/doc/snippets/multimedia-snippets/multimedia-snippets.pro
@@ -22,4 +22,5 @@ SOURCES += \
 
 OTHER_FILES += \
     soundeffect.qml \
-    qtvideosink.qml
+    qtvideosink.qml \
+    multiple-videooutputs.qml
diff --git a/src/multimedia/doc/snippets/multimedia-snippets/multiple-videooutputs.qml b/src/multimedia/doc/snippets/multimedia-snippets/multiple-videooutputs.qml
new file mode 100644
index 000000000..e3c1587f6
--- /dev/null
+++ b/src/multimedia/doc/snippets/multimedia-snippets/multiple-videooutputs.qml
@@ -0,0 +1,67 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.0
+import QtQuick.Window 2.2
+import QtMultimedia 5.15
+
+//! [complete]
+Item {
+    MediaPlayer {
+        id: mediaplayer
+        autoPlay: true
+        source: "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4"
+        videoOutput: [v1, v2]
+    }
+
+    VideoOutput {
+        id: v1
+        anchors.fill: parent
+    }
+
+    Window {
+        visible: true
+        width: 480; height: 320
+        VideoOutput {
+            id: v2
+            anchors.fill: parent
+        }
+    }
+}
+//! [complete]
diff --git a/src/multimedia/playback/qmediaplayer.cpp b/src/multimedia/playback/qmediaplayer.cpp
index 9b51bcddf..d96cb3a95 100644
--- a/src/multimedia/playback/qmediaplayer.cpp
+++ b/src/multimedia/playback/qmediaplayer.cpp
@@ -1184,7 +1184,7 @@ void QMediaPlayer::setVideoOutput(QAbstractVideoSurface *surface)
 
 void QMediaPlayer::setVideoOutput(const QVector<QAbstractVideoSurface *> &surfaces)
 {
-    setVideoOutput(new QVideoSurfaces(surfaces, this));
+    setVideoOutput(!surfaces.empty() ? new QVideoSurfaces(surfaces, this) : nullptr);
 }
 
 /*! \reimp */