[MSE][GStreamer] Avoid extra/circular refs between tracks/streams

https://bugs.webkit.org/show_bug.cgi?id=273488

Reviewed by Alicia Boya Garcia.

1. Avoid adding the same stream to the hash map. Also keeping the active/valid tracks in the player.
2. Avoid a hard reference in the source buffer when ready for more samples.
3. Break the indirect circular reference between the stream and track through the pad.

* Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.cpp:
(WebCore::filterOutRepeatingTracks):
(WebCore::MediaPlayerPrivateGStreamerMSE::sourceSetup):
(WebCore::MediaPlayerPrivateGStreamerMSE::startSource):
* Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.cpp:
(WebCore::SourceBufferPrivateGStreamer::notifyClientWhenReadyForMoreSamples):
* Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.h:
* Source/WebCore/platform/graphics/gstreamer/mse/WebKitMediaSourceGStreamer.cpp:
(webKitMediaSrcEmitStreams):
(webKitMediaSrcActivateMode):
(webKitMediaSrcPadLinked):
(webKitMediaSrcLoop):

Canonical link: https://commits.webkit.org/278259@main

Author: calvaris

Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.cpp

@@ -165,6 +165,20 @@ class MediaPlayerFactoryGStreamerMSE final : public MediaPlayerFactory {
     }
 };
 
+static Vector<RefPtr<MediaSourceTrackGStreamer>> filterOutRepeatingTracks(const Vector<RefPtr<MediaSourceTrackGStreamer>>& tracks)
+{
+    Vector<RefPtr<MediaSourceTrackGStreamer>> uniqueTracks;
+    uniqueTracks.reserveInitialCapacity(tracks.size());
+
+    for (const auto& track : tracks) {
+        if (!uniqueTracks.containsIf([&track](const auto& current) { return track->trackId() == current->trackId(); }))
+            uniqueTracks.append(track);
+    }
+
+    uniqueTracks.shrinkToFit();
+    return uniqueTracks;
+}
+
 void MediaPlayerPrivateGStreamerMSE::registerMediaEngine(MediaEngineRegistrar registrar)
 {
     GST_DEBUG_CATEGORY_INIT(webkit_mse_debug, "webkitmse", 0, "WebKit MSE media player");
@@ -380,8 +394,10 @@ void MediaPlayerPrivateGStreamerMSE::sourceSetup(GstElement* sourceElement)
     webKitMediaSrcSetPlayer(WEBKIT_MEDIA_SRC(sourceElement), WeakPtr { *this });
     m_source = sourceElement;
 
-    if (m_mediaSourcePrivate->hasAllTracks())
+    if (m_mediaSourcePrivate && m_mediaSourcePrivate->hasAllTracks()) {
+        m_tracks = filterOutRepeatingTracks(m_tracks);
         webKitMediaSrcEmitStreams(WEBKIT_MEDIA_SRC(m_source.get()), m_tracks);
+    }
 }
 
 void MediaPlayerPrivateGStreamerMSE::updateStates()
@@ -443,8 +459,8 @@ void MediaPlayerPrivateGStreamerMSE::setInitialVideoSize(const FloatSize& videoS
 
 void MediaPlayerPrivateGStreamerMSE::startSource(const Vector<RefPtr<MediaSourceTrackGStreamer>>& tracks)
 {
-    m_tracks = tracks;
-    webKitMediaSrcEmitStreams(WEBKIT_MEDIA_SRC(m_source.get()), tracks);
+    m_tracks = filterOutRepeatingTracks(tracks);
+    webKitMediaSrcEmitStreams(WEBKIT_MEDIA_SRC(m_source.get()), m_tracks);
 }
 
 void MediaPlayerPrivateGStreamerMSE::getSupportedTypes(HashSet<String, ASCIICaseInsensitiveHash>& types)

Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.cpp

@@ -183,9 +183,12 @@ bool SourceBufferPrivateGStreamer::isReadyForMoreSamples(const AtomString& track
 void SourceBufferPrivateGStreamer::notifyClientWhenReadyForMoreSamples(const AtomString& trackId)
 {
     ASSERT(isMainThread());
+    ASSERT(m_tracks.contains(trackId));
     MediaSourceTrackGStreamer* track = m_tracks.get(trackId);
-    track->notifyWhenReadyForMoreSamples([protector = Ref { *this }, this, trackId]() mutable {
-        RunLoop::main().dispatch([protector = WTFMove(protector), this, trackId]() {
+    track->notifyWhenReadyForMoreSamples([weakPtr = WeakPtr { *this }, this, trackId]() mutable {
+        RunLoop::main().dispatch([weakPtr = WTFMove(weakPtr), this, trackId]() {
+            if (!weakPtr)
+                return;
             if (!m_hasBeenRemovedFromMediaSource)
                 provideMediaData(trackId);
         });

Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.h

@@ -50,7 +50,7 @@ class AppendPipeline;
 class MediaSourcePrivateGStreamer;
 class MediaSourceTrackGStreamer;
 
-class SourceBufferPrivateGStreamer final : public SourceBufferPrivate {
+class SourceBufferPrivateGStreamer final : public SourceBufferPrivate, public CanMakeWeakPtr<SourceBufferPrivateGStreamer> {
 public:
     static bool isContentTypeSupported(const ContentType&);
     static Ref<SourceBufferPrivateGStreamer> create(MediaSourcePrivateGStreamer*, const ContentType&, MediaPlayerPrivateGStreamerMSE&);

Source/WebCore/platform/graphics/gstreamer/mse/WebKitMediaSourceGStreamer.cpp

@@ -105,7 +105,7 @@ static MediaPlayerPrivateGStreamerMSE* webKitMediaSrcPlayer(WebKitMediaSrc*);
 #define webkit_media_src_parent_class parent_class
 
 struct WebKitMediaSrcPadPrivate {
-    RefPtr<Stream> stream;
+    WeakPtr<Stream> stream;
 };
 
 struct WebKitMediaSrcPad {
@@ -154,7 +154,7 @@ WEBKIT_DEFINE_TYPE_WITH_CODE(WebKitMediaSrc, webkit_media_src, GST_TYPE_ELEMENT,
     G_IMPLEMENT_INTERFACE(GST_TYPE_URI_HANDLER, webKitMediaSrcUriHandlerInit);
     GST_DEBUG_CATEGORY_INIT(webkit_media_src_debug, "webkitmediasrc", 0, "WebKit MSE source element"));
 
-struct Stream : public ThreadSafeRefCounted<Stream> {
+struct Stream : public ThreadSafeRefCounted<Stream>, CanMakeWeakPtr<Stream> {
     Stream(WebKitMediaSrc* source, GRefPtr<GstPad>&& pad, Ref<MediaSourceTrackGStreamer>&& track, GRefPtr<GstStream>&& streamInfo)
         : source(source)
         , pad(WTFMove(pad))
@@ -306,14 +306,19 @@ void webKitMediaSrcEmitStreams(WebKitMediaSrc* source, const Vector<RefPtr<Media
     source->priv->collection = adoptGRef(gst_stream_collection_new("WebKitMediaSrc"));
     for (const auto& track : tracks) {
         GST_DEBUG_OBJECT(source, "Adding stream with trackId '%s' of type %s with caps %" GST_PTR_FORMAT, track->trackId().string().utf8().data(), streamTypeToString(track->type()), track->initialCaps().get());
+        if (source->priv->streams.contains(track->trackId())) {
+            GST_ERROR_OBJECT(source, "stream with trackId '%s' already exists", track->trackId().string().utf8().data());
+            ASSERT_NOT_REACHED();
+            continue;
+        }
 
         GRefPtr<WebKitMediaSrcPad> pad = WEBKIT_MEDIA_SRC_PAD(g_object_new(webkit_media_src_pad_get_type(), "name", makeString("src_", track->trackId()).utf8().data(), "direction", GST_PAD_SRC, NULL));
         gst_pad_set_activatemode_function(GST_PAD(pad.get()), webKitMediaSrcActivateMode);
 
         ASSERT(track->initialCaps());
         auto stream = adoptRef(new Stream(source, GRefPtr<GstPad>(GST_PAD(pad.get())), *track,
             adoptGRef(gst_stream_new(track->trackId().string().utf8().data(), track->initialCaps().get(), gstStreamType(track->type()), GST_STREAM_FLAG_SELECT))));
-        pad->priv->stream = stream;
+        pad->priv->stream = WeakPtr { *stream.get() };
 
         gst_stream_collection_add_stream(source->priv->collection.get(), GRefPtr<GstStream>(stream->streamInfo.get()).leakRef());
         source->priv->streams.set(track->trackId(), WTFMove(stream));
@@ -375,8 +380,11 @@ static gboolean webKitMediaSrcActivateMode(GstPad* pad, GstObject* source, GstPa
     if (active)
         gst_pad_start_task(pad, webKitMediaSrcLoop, pad, nullptr);
     else {
+        RefPtr<Stream> stream(WEBKIT_MEDIA_SRC_PAD(pad)->priv->stream.get());
+        if (!stream)
+            return false;
+
         // Unblock the streaming thread.
-        RefPtr<Stream>& stream = WEBKIT_MEDIA_SRC_PAD(pad)->priv->stream;
         {
             DataMutexLocker streamingMembers { stream->streamingMembersDataMutex };
             streamingMembers->isFlushing = true;
@@ -397,7 +405,10 @@ static gboolean webKitMediaSrcActivateMode(GstPad* pad, GstObject* source, GstPa
 
 static void webKitMediaSrcPadLinked(GstPad* pad, GstPad*, void*)
 {
-    RefPtr<Stream>& stream = WEBKIT_MEDIA_SRC_PAD(pad)->priv->stream;
+    RefPtr<Stream> stream(WEBKIT_MEDIA_SRC_PAD(pad)->priv->stream.get());
+    if (!stream)
+        return;
+
     DataMutexLocker streamingMembers { stream->streamingMembersDataMutex };
     streamingMembers->padLinkedOrFlushedCondition.notifyOne();
 }
@@ -424,7 +435,9 @@ static void webKitMediaSrcWaitForPadLinkedOrFlush(GstPad* pad, DataMutexLocker<S
 static void webKitMediaSrcLoop(void* userData)
 {
     GstPad* pad = GST_PAD(userData);
-    RefPtr<Stream>& stream = WEBKIT_MEDIA_SRC_PAD(pad)->priv->stream;
+    RefPtr<Stream> stream(WEBKIT_MEDIA_SRC_PAD(pad)->priv->stream.get());
+    if (!stream)
+        return;
 
     DataMutexLocker streamingMembers { stream->streamingMembersDataMutex };
     if (streamingMembers->isFlushing) {