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/*
* Copyright (C) 2013 Cable Television Laboratories, Inc.
* Copyright (C) 2021 Igalia S.L
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* 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 APPLE INC. OR ITS 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.
*/
#include "config.h"
#include "TextSinkGStreamer.h"
#if ENABLE(VIDEO) && USE(GSTREAMER)
#include "GStreamerCommon.h"
#include "MediaPlayerPrivateGStreamer.h"
#include <gst/app/gstappsink.h>
#include <wtf/glib/WTFGType.h>
GST_DEBUG_CATEGORY_STATIC(webkitTextSinkDebug);
#define GST_CAT_DEFAULT webkitTextSinkDebug
using namespace WebCore;
struct _WebKitTextSinkPrivate {
GRefPtr<GstElement> appSink;
ThreadSafeWeakPtr<MediaPlayerPrivateGStreamer> mediaPlayerPrivate;
std::optional<TrackID> streamId;
};
WEBKIT_DEFINE_TYPE_WITH_CODE(WebKitTextSink, webkit_text_sink, GST_TYPE_BIN,
GST_DEBUG_CATEGORY_INIT(webkitTextSinkDebug, "webkittextsink", 0, "webkit text sink"))
static void webkitTextSinkHandleSample(WebKitTextSink* self, GRefPtr<GstSample>&& sample)
{
auto* priv = self->priv;
if (!priv->streamId) {
auto pad = adoptGRef(gst_element_get_static_pad(priv->appSink.get(), "sink"));
priv->streamId = getStreamIdFromPad(pad.get());
}
if (UNLIKELY(!priv->streamId)) {
GST_WARNING_OBJECT(self, "Unable to handle sample with no stream start event.");
return;
}
// Player private methods that interact with WebCore must run from the main thread. Things can
// be destroyed before that code runs, including the text sink and priv, so pass everything in a
// safe way.
callOnMainThread([mediaPlayerPrivate = ThreadSafeWeakPtr<MediaPlayerPrivateGStreamer>(priv->mediaPlayerPrivate), streamId = priv->streamId.value(), sample = WTFMove(sample)]() mutable {
RefPtr player = mediaPlayerPrivate.get();
if (!player)
return;
player->handleTextSample(WTFMove(sample), streamId);
});
}
static void webkitTextSinkConstructed(GObject* object)
{
G_OBJECT_CLASS(webkit_text_sink_parent_class)->constructed(object);
auto* sink = WEBKIT_TEXT_SINK(object);
auto* priv = sink->priv;
priv->appSink = makeGStreamerElement("appsink", nullptr);
gst_bin_add(GST_BIN_CAST(sink), priv->appSink.get());
auto pad = adoptGRef(gst_element_get_static_pad(priv->appSink.get(), "sink"));
gst_element_add_pad(GST_ELEMENT_CAST(sink), gst_ghost_pad_new("sink", pad.get()));
auto textCaps = adoptGRef(gst_caps_new_empty_simple("application/x-subtitle-vtt"));
g_object_set(priv->appSink.get(), "emit-signals", TRUE, "enable-last-sample", FALSE, "caps", textCaps.get(), nullptr);
g_signal_connect(priv->appSink.get(), "new-sample", G_CALLBACK(+[](GstElement* appSink, WebKitTextSink* sink) -> GstFlowReturn {
webkitTextSinkHandleSample(sink, adoptGRef(gst_app_sink_pull_sample(GST_APP_SINK(appSink))));
return GST_FLOW_OK;
}), sink);
g_signal_connect(priv->appSink.get(), "new-preroll", G_CALLBACK(+[](GstElement* appSink, WebKitTextSink* sink) -> GstFlowReturn {
webkitTextSinkHandleSample(sink, adoptGRef(gst_app_sink_pull_preroll(GST_APP_SINK(appSink))));
return GST_FLOW_OK;
}), sink);
// We want to get cues as quickly as possible so WebKit has time to handle them,
// and we don't want cues to block when they come in the wrong order.
gst_base_sink_set_sync(GST_BASE_SINK_CAST(sink->priv->appSink.get()), false);
}
static gboolean webkitTextSinkQuery(GstElement* element, GstQuery* query)
{
switch (GST_QUERY_TYPE(query)) {
case GST_QUERY_DURATION:
case GST_QUERY_POSITION:
// Ignore duration and position because we don't want the seek bar to be based on where the cues are.
return false;
default:
return GST_ELEMENT_CLASS(webkit_text_sink_parent_class)->query(element, query);
}
}
static void webkit_text_sink_class_init(WebKitTextSinkClass* klass)
{
auto* gobjectClass = G_OBJECT_CLASS(klass);
auto* elementClass = GST_ELEMENT_CLASS(klass);
gst_element_class_set_metadata(elementClass, "WebKit text sink", GST_ELEMENT_FACTORY_KLASS_SINK,
"WebKit's text sink collecting cues encoded in WebVTT by the WebKit text-combiner",
"Brendan Long <b.long@cablelabs.com>");
gobjectClass->constructed = GST_DEBUG_FUNCPTR(webkitTextSinkConstructed);
elementClass->query = GST_DEBUG_FUNCPTR(webkitTextSinkQuery);
}
GstElement* webkitTextSinkNew(ThreadSafeWeakPtr<MediaPlayerPrivateGStreamer>&& player)
{
auto* element = GST_ELEMENT_CAST(g_object_new(WEBKIT_TYPE_TEXT_SINK, nullptr));
auto* sink = WEBKIT_TEXT_SINK(element);
ASSERT(isMainThread());
sink->priv->mediaPlayerPrivate = WTFMove(player);
return element;
}
#undef GST_CAT_DEFAULT
#endif // ENABLE(VIDEO) && USE(GSTREAMER)
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