1 files changed, 155 insertions, 0 deletions
diff --git a/src/plugins/multimedia/gstreamer/common/qgstsubtitlesink.cpp b/src/plugins/multimedia/gstreamer/common/qgstsubtitlesink.cpp
new file mode 100644
index 000000000..c6b230d85
--- /dev/null
+++ b/src/plugins/multimedia/gstreamer/common/qgstsubtitlesink.cpp
@@ -0,0 +1,155 @@
+// Copyright (C) 2021 The Qt Company
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include <QDebug>
+#include <QThread>
+#include <QEvent>
+
+#include "qgstreamervideosink_p.h"
+#include "qgstsubtitlesink_p.h"
+
+QT_BEGIN_NAMESPACE
+
+static GstBaseSinkClass *gst_sink_parent_class;
+static thread_local QGstreamerVideoSink *gst_current_sink;
+
+#define ST_SINK(s) QGstSubtitleSink *sink(reinterpret_cast<QGstSubtitleSink *>(s))
+
+QGstSubtitleSink *QGstSubtitleSink::createSink(QGstreamerVideoSink *sink)
+{
+    gst_current_sink = sink;
+
+    QGstSubtitleSink *gstSink = reinterpret_cast<QGstSubtitleSink *>(
+            g_object_new(QGstSubtitleSink::get_type(), nullptr));
+    g_object_set(gstSink, "async", false, nullptr);
+
+    return gstSink;
+}
+
+GType QGstSubtitleSink::get_type()
+{
+    static const GTypeInfo info =
+    {
+        sizeof(QGstSubtitleSinkClass),                    // class_size
+        base_init,                                         // base_init
+        nullptr,                                           // base_finalize
+        class_init,                                        // class_init
+        nullptr,                                           // class_finalize
+        nullptr,                                           // class_data
+        sizeof(QGstSubtitleSink),                         // instance_size
+        0,                                                 // n_preallocs
+        instance_init,                                     // instance_init
+        nullptr                                                  // value_table
+    };
+
+    static const GType type = []() {
+        const auto result = g_type_register_static(
+                GST_TYPE_BASE_SINK, "QGstSubtitleSink", &info, GTypeFlags(0));
+
+        // Register the sink type to be used in custom piplines.
+        // When surface is ready the sink can be used.
+        gst_element_register(nullptr, "qtsubtitlesink", GST_RANK_PRIMARY, result);
+
+        return result;
+    }();
+
+    return type;
+}
+
+void QGstSubtitleSink::class_init(gpointer g_class, gpointer class_data)
+{
+    Q_UNUSED(class_data);
+
+    gst_sink_parent_class = reinterpret_cast<GstBaseSinkClass *>(g_type_class_peek_parent(g_class));
+
+    GstBaseSinkClass *base_sink_class = reinterpret_cast<GstBaseSinkClass *>(g_class);
+    base_sink_class->render = QGstSubtitleSink::render;
+    base_sink_class->get_caps = QGstSubtitleSink::get_caps;
+    base_sink_class->set_caps = QGstSubtitleSink::set_caps;
+    base_sink_class->propose_allocation = QGstSubtitleSink::propose_allocation;
+    base_sink_class->wait_event = QGstSubtitleSink::wait_event;
+
+    GstElementClass *element_class = reinterpret_cast<GstElementClass *>(g_class);
+    element_class->change_state = QGstSubtitleSink::change_state;
+    gst_element_class_set_metadata(element_class,
+        "Qt built-in subtitle sink",
+        "Sink/Subtitle",
+        "Qt default built-in subtitle sink",
+        "The Qt Company");
+
+    GObjectClass *object_class = reinterpret_cast<GObjectClass *>(g_class);
+    object_class->finalize = QGstSubtitleSink::finalize;
+}
+
+void QGstSubtitleSink::base_init(gpointer g_class)
+{
+    static GstStaticPadTemplate sink_pad_template = GST_STATIC_PAD_TEMPLATE(
+            "sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS("ANY"));
+
+    gst_element_class_add_pad_template(
+            GST_ELEMENT_CLASS(g_class), gst_static_pad_template_get(&sink_pad_template));
+}
+
+void QGstSubtitleSink::instance_init(GTypeInstance *instance, gpointer g_class)
+{
+    Q_UNUSED(g_class);
+    ST_SINK(instance);
+
+    Q_ASSERT(gst_current_sink);
+    sink->sink = gst_current_sink;
+    gst_current_sink = nullptr;
+}
+
+void QGstSubtitleSink::finalize(GObject *object)
+{
+    // Chain up
+    G_OBJECT_CLASS(gst_sink_parent_class)->finalize(object);
+}
+
+GstStateChangeReturn QGstSubtitleSink::change_state(GstElement *element, GstStateChange transition)
+{
+    return GST_ELEMENT_CLASS(gst_sink_parent_class)->change_state(element, transition);
+}
+
+GstCaps *QGstSubtitleSink::get_caps(GstBaseSink *base, GstCaps *filter)
+{
+    return gst_sink_parent_class->get_caps(base, filter);
+}
+
+gboolean QGstSubtitleSink::set_caps(GstBaseSink *base, GstCaps *caps)
+{
+    qDebug() << "set_caps:" << caps;
+    return gst_sink_parent_class->set_caps(base, caps);
+}
+
+gboolean QGstSubtitleSink::propose_allocation(GstBaseSink *base, GstQuery *query)
+{
+    return gst_sink_parent_class->propose_allocation(base, query);
+}
+
+GstFlowReturn QGstSubtitleSink::wait_event(GstBaseSink *base, GstEvent *event)
+{
+    GstFlowReturn retval = gst_sink_parent_class->wait_event(base, event);
+    ST_SINK(base);
+    if (event->type == GST_EVENT_GAP) {
+//        qDebug() << "gap, clearing subtitle";
+        sink->sink->setSubtitleText(QString());
+    }
+    return retval;
+}
+
+GstFlowReturn QGstSubtitleSink::render(GstBaseSink *base, GstBuffer *buffer)
+{
+    ST_SINK(base);
+    GstMemory *mem = gst_buffer_get_memory(buffer, 0);
+    GstMapInfo info;
+    QString subtitle;
+    if (gst_memory_map(mem, &info, GST_MAP_READ))
+        subtitle = QString::fromUtf8(reinterpret_cast<const char *>(info.data));
+    gst_memory_unmap(mem, &info);
+//    qDebug() << "render" << buffer << subtitle;
+    sink->sink->setSubtitleText(subtitle);
+    return GST_FLOW_OK;
+}
+
+QT_END_NAMESPACE