GStreamer: introduce `QGstAppSrc` wrapper object

Pick-to: 6.5 6.6 6.7
Change-Id: Ic37390d74d0d6faac34d55c6dbe257ff30b437a0
Reviewed-by: Jøger Hansegård <joger.hansegard@qt.io>
Reviewed-by: Artem Dyomin <artem.dyomin@qt.io>

5 files changed, 109 insertions, 21 deletions

diff --git a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
index 6777bc2bc..240c69b5b 100644
--- a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
+++ b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
@@ -93,11 +93,10 @@ QGstreamerAudioDecoder::~QGstreamerAudioDecoder()
 }
 
 #if QT_CONFIG(gstreamer_app)
-void QGstreamerAudioDecoder::configureAppSrcElement(GObject* object, GObject *orig, GParamSpec *pspec, QGstreamerAudioDecoder *self)
+void QGstreamerAudioDecoder::configureAppSrcElement([[maybe_unused]] GObject *object, GObject *orig,
+                                                    [[maybe_unused]] GParamSpec *pspec,
+                                                    QGstreamerAudioDecoder *self)
 {
-    Q_UNUSED(object);
-    Q_UNUSED(pspec);
-
     // In case we switch from appsrc to not
     if (!self->m_appSrc)
         return;
@@ -106,8 +105,10 @@ void QGstreamerAudioDecoder::configureAppSrcElement(GObject* object, GObject *or
     g_object_get(orig, "source", &appsrc, NULL);
 
     auto *qAppSrc = self->m_appSrc;
-    qAppSrc->setExternalAppSrc(
-            QGstElement(appsrc.get(), QGstElement::NeedsRef)); // CHECK: can we `release()`?
+    qAppSrc->setExternalAppSrc(QGstAppSrc{
+            qGstSafeCast<GstAppSrc>(appsrc.get()),
+            QGstAppSrc::NeedsRef, // CHECK: can we `release()`?
+    });
     qAppSrc->setup(self->mDevice);
 }
 #endif
diff --git a/src/plugins/multimedia/gstreamer/common/qgst.cpp b/src/plugins/multimedia/gstreamer/common/qgst.cpp
index 2d7dd1bce..4f4f28d97 100644
--- a/src/plugins/multimedia/gstreamer/common/qgst.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgst.cpp
@@ -1056,6 +1056,21 @@ GstBaseSink *QGstBaseSink::baseSink() const
     return qGstCheckedCast<GstBaseSink>(element());
 }
 
+// QGstBaseSrc
+
+QGstBaseSrc::QGstBaseSrc(GstBaseSrc *element, RefMode mode)
+    : QGstElement{
+          qGstCheckedCast<GstElement>(element),
+          mode,
+      }
+{
+}
+
+GstBaseSrc *QGstBaseSrc::baseSrc() const
+{
+    return qGstCheckedCast<GstBaseSrc>(element());
+}
+
 #if QT_CONFIG(gstreamer_app)
 
 // QGstAppSink
@@ -1101,6 +1116,41 @@ QGstSampleHandle QGstAppSink::pullSample()
     };
 }
 
+// QGstAppSrc
+
+QGstAppSrc::QGstAppSrc(GstAppSrc *element, RefMode mode)
+    : QGstBaseSrc{
+          qGstCheckedCast<GstBaseSrc>(element),
+          mode,
+      }
+{
+}
+
+QGstAppSrc QGstAppSrc::create(const char *name)
+{
+    QGstElement created = QGstElement::createFromFactory("appsrc", name);
+    return QGstAppSrc{
+        qGstCheckedCast<GstAppSrc>(created.element()),
+        QGstAppSrc::NeedsRef,
+    };
+}
+
+GstAppSrc *QGstAppSrc::appSrc() const
+{
+    return qGstCheckedCast<GstAppSrc>(element());
+}
+
+void QGstAppSrc::setCallbacks(GstAppSrcCallbacks &callbacks, gpointer user_data,
+                              GDestroyNotify notify)
+{
+    gst_app_src_set_callbacks(appSrc(), &callbacks, user_data, notify);
+}
+
+GstFlowReturn QGstAppSrc::pushBuffer(GstBuffer *buffer)
+{
+    return gst_app_src_push_buffer(appSrc(), buffer);
+}
+
 #endif
 
 QT_END_NAMESPACE
diff --git a/src/plugins/multimedia/gstreamer/common/qgst_p.h b/src/plugins/multimedia/gstreamer/common/qgst_p.h
index 51383fd3a..3c97ee604 100644
--- a/src/plugins/multimedia/gstreamer/common/qgst_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgst_p.h
@@ -695,6 +695,21 @@ public:
     GstBaseSink *baseSink() const;
 };
 
+class QGstBaseSrc : public QGstElement
+{
+public:
+    using QGstElement::QGstElement;
+
+    explicit QGstBaseSrc(GstBaseSrc *, RefMode);
+
+    QGstBaseSrc(const QGstBaseSrc &) = default;
+    QGstBaseSrc(QGstBaseSrc &&) noexcept = default;
+    QGstBaseSrc &operator=(const QGstBaseSrc &) = default;
+    QGstBaseSrc &operator=(QGstBaseSrc &&) noexcept = default;
+
+    GstBaseSrc *baseSrc() const;
+};
+
 #if QT_CONFIG(gstreamer_app)
 class QGstAppSink : public QGstBaseSink
 {
@@ -717,6 +732,28 @@ public:
 
     QGstSampleHandle pullSample();
 };
+
+class QGstAppSrc : public QGstBaseSrc
+{
+public:
+    using QGstBaseSrc::QGstBaseSrc;
+
+    explicit QGstAppSrc(GstAppSrc *, RefMode);
+
+    QGstAppSrc(const QGstAppSrc &) = default;
+    QGstAppSrc(QGstAppSrc &&) noexcept = default;
+    QGstAppSrc &operator=(const QGstAppSrc &) = default;
+    QGstAppSrc &operator=(QGstAppSrc &&) noexcept = default;
+
+    static QGstAppSrc create(const char *name);
+
+    GstAppSrc *appSrc() const;
+
+    void setCallbacks(GstAppSrcCallbacks &callbacks, gpointer user_data, GDestroyNotify notify);
+
+    GstFlowReturn pushBuffer(GstBuffer *); // take ownership
+};
+
 #endif
 
 inline QString errorMessageCannotFindElement(std::string_view element)
diff --git a/src/plugins/multimedia/gstreamer/common/qgstappsource.cpp b/src/plugins/multimedia/gstreamer/common/qgstappsource.cpp
index 78443ac19..e27f32f1a 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstappsource.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstappsource.cpp
@@ -14,14 +14,14 @@ QT_BEGIN_NAMESPACE
 
 QMaybe<QGstAppSource *> QGstAppSource::create(QObject *parent)
 {
-    QGstElement appsrc = QGstElement::createFromFactory("appsrc", "appsrc");
+    QGstAppSrc appsrc = QGstAppSrc::create("appsrc");
     if (!appsrc)
         return errorMessageCannotFindElement("appsrc");
 
     return new QGstAppSource(appsrc, parent);
 }
 
-QGstAppSource::QGstAppSource(QGstElement appsrc, QObject *parent)
+QGstAppSource::QGstAppSource(QGstAppSrc appsrc, QObject *parent)
     : QObject(parent), m_appSrc(std::move(appsrc))
 {
 }
@@ -41,14 +41,14 @@ bool QGstAppSource::setup(QIODevice *stream, qint64 offset)
     if (!setStream(stream, offset))
         return false;
 
-    auto *appSrc = GST_APP_SRC(m_appSrc.element());
-    GstAppSrcCallbacks m_callbacks;
-    memset(&m_callbacks, 0, sizeof(GstAppSrcCallbacks));
-    m_callbacks.need_data = &QGstAppSource::on_need_data;
-    m_callbacks.enough_data = &QGstAppSource::on_enough_data;
-    m_callbacks.seek_data = &QGstAppSource::on_seek_data;
-    gst_app_src_set_callbacks(appSrc, (GstAppSrcCallbacks*)&m_callbacks, this, nullptr);
+    GstAppSrcCallbacks callbacks{};
+    callbacks.need_data = QGstAppSource::on_need_data;
+    callbacks.enough_data = QGstAppSource::on_enough_data;
+    callbacks.seek_data = QGstAppSource::on_seek_data;
 
+    m_appSrc.setCallbacks(callbacks, this, nullptr);
+
+    GstAppSrc *appSrc = m_appSrc.appSrc();
     m_maxBytes = gst_app_src_get_max_bytes(appSrc);
     m_suspended = false;
 
@@ -76,9 +76,9 @@ void QGstAppSource::setAudioFormat(const QAudioFormat &f)
     m_appSrc.set("format", GST_FORMAT_TIME);
 }
 
-void QGstAppSource::setExternalAppSrc(const QGstElement &appsrc)
+void QGstAppSource::setExternalAppSrc(QGstAppSrc appsrc)
 {
-    m_appSrc = appsrc;
+    m_appSrc = std::move(appsrc);
 }
 
 bool QGstAppSource::setStream(QIODevice *stream, qint64 offset)
@@ -201,7 +201,7 @@ void QGstAppSource::pushData()
     m_noMoreData = false;
     emit bytesProcessed(bytesRead);
 
-    GstFlowReturn ret = gst_app_src_push_buffer(GST_APP_SRC(m_appSrc.element()), buffer);
+    GstFlowReturn ret = m_appSrc.pushBuffer(buffer);
     if (ret == GST_FLOW_ERROR) {
         qWarning() << "QGstAppSrc: push buffer error";
     } else if (ret == GST_FLOW_FLUSHING) {
diff --git a/src/plugins/multimedia/gstreamer/common/qgstappsource_p.h b/src/plugins/multimedia/gstreamer/common/qgstappsource_p.h
index e25398001..bcfb0b530 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstappsource_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgstappsource_p.h
@@ -39,7 +39,7 @@ public:
     bool setup(QIODevice *stream = nullptr, qint64 offset = 0);
     void setAudioFormat(const QAudioFormat &f);
 
-    void setExternalAppSrc(const QGstElement &appsrc);
+    void setExternalAppSrc(QGstAppSrc);
     QGstElement element();
 
     void write(const char *data, qsizetype size);
@@ -60,7 +60,7 @@ private Q_SLOTS:
 
     void streamDestroyed();
 private:
-    QGstAppSource(QGstElement appsrc, QObject *parent);
+    QGstAppSource(QGstAppSrc appsrc, QObject *parent);
 
     bool setStream(QIODevice *, qint64 offset);
     bool isStreamValid() const
@@ -79,7 +79,7 @@ private:
     QRingBuffer m_buffer;
     QAudioFormat m_format;
 
-    QGstElement m_appSrc;
+    QGstAppSrc m_appSrc;
     bool m_sequential = true;
     bool m_suspended = false;
     bool m_noMoreData = false;