tmp example

examples/streamer/streamer.cpp

+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "streamer.h"
+#include <QQuickItemGrabResult>
+
+Streamer::Streamer(QObject *parent)
+    : QGstreamerPipeline(parent)
+{
+    connect(this, &QGstreamerPipeline::pipelineChanged,
+        this, &Streamer::onPipelineChanged);
+}
+
+QObject *Streamer::item() const
+{
+    return m_item;
+}
+
+void Streamer::setItem(QObject *src)
+{
+    if (src == m_item)
+        return;
+
+    m_item = qobject_cast<QQuickItem*>(src);
+    emit itemChanged();
+}
+
+void Streamer::onPipelineChanged()
+{
+    GstElement *pl = pipeline();
+    if (!pl)
+        return;
+
+    auto appsrc = gst_bin_get_by_name(GST_BIN(pl), "source");
+    if (!appsrc)
+        return;
+
+    m_appsrc.reset(new AppSrc(this, appsrc));
+}
+
+QVideoFrame AppSrc::readFrame() const
+{
+    if (!m_frame.isValid() && m_streamer->item()) {
+        auto result = qobject_cast<QQuickItem*>(m_streamer->item())->grabToImage();
+        connect(result.data(), &QQuickItemGrabResult::ready, result.data(), [this, result](){
+            m_frame = result->image();
+        });
+    }
+
+    auto frame = m_frame;
+    m_frame = QVideoFrame();
+
+    return frame;
+}

examples/streamer/streamer.h

+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef STREAMER_H
+#define STREAMER_H
+
+#include <QGstreamerPipeline>
+#include <QGstreamerAppSrc>
+#include <QScopedPointer>
+#include <QPointer>
+#include <QQuickWindow>
+#include <QQuickItem>
+
+class Streamer;
+class AppSrc : public QGstreamerAppSrc
+{
+    Q_OBJECT
+public:
+    AppSrc(Streamer *streamer, GstElement *appsrc, QObject *parent = nullptr)
+        : QGstreamerAppSrc(appsrc, parent)
+        , m_streamer(streamer)
+    {
+    }
+
+protected:
+    QVideoFrame readFrame() const override;
+
+private:
+    Streamer *m_streamer = nullptr;
+    mutable QVideoFrame m_frame;
+};
+
+class Streamer : public QGstreamerPipeline
+{
+    Q_OBJECT
+    Q_PROPERTY(QObject* item READ item WRITE setItem NOTIFY itemChanged)
+
+public:
+    Streamer(QObject *parent = nullptr);
+
+    QObject *item() const;
+    void setItem(QObject *item);
+
+Q_SIGNALS:
+    void windowChanged();
+    void itemChanged();
+
+private Q_SLOTS:
+    void onPipelineChanged();
+
+private:
+    QScopedPointer<AppSrc> m_appsrc;    
+    QQuickItem *m_item;
+};
+
+#endif