[MSE SourceBuffer] Disable audio flush on samples replacement for Spotify (#1244)

With edit lists enabled recently, Spotify started to append
the same segment multiple times that to samples replacement
and audio flush. As a result audio is breaking on every append.

Disable audio flush on samples replacement for Spotify
until this is fixed by Spotify

Author: asurdej-comcast

Source/WebCore/Modules/mediasource/SourceBuffer.cpp

@@ -40,6 +40,7 @@
 #include "BufferSource.h"
 #include "BufferedChangeEvent.h"
 #include "ContentTypeUtilities.h"
+#include "DocumentInlines.h"
 #include "Event.h"
 #include "EventNames.h"
 #include "HTMLMediaElement.h"
@@ -48,6 +49,7 @@
 #include "Logging.h"
 #include "MediaDescription.h"
 #include "MediaSource.h"
+#include "Quirks.h"
 #include "Settings.h"
 #include "SharedBuffer.h"
 #include "SourceBufferList.h"
@@ -185,6 +187,11 @@ SourceBuffer::SourceBuffer(Ref<SourceBufferPrivate>&& sourceBufferPrivate, Media
 
     m_private->setClient(m_client);
     m_private->setMaximumBufferSize(maximumBufferSize());
+
+    RefPtr document = dynamicDowncast<Document>(scriptExecutionContext());
+    if (document && document->quirks().shouldBypassAudioFlushOnSampleReplacement()) {
+        m_private->setShouldBypassAudioFlushOnSampleReplacement(true);
+    }
 }
 
 SourceBuffer::~SourceBuffer()

Source/WebCore/page/Quirks.cpp

@@ -1963,4 +1963,22 @@ std::optional<TargetedElementSelectors> Quirks::defaultVisibilityAdjustmentSelec
 #endif
 }
 
+#if ENABLE(MEDIA_SOURCE)
+bool Quirks::shouldBypassAudioFlushOnSampleReplacement() const
+{
+    if (!needsQuirks())
+        return false;
+
+    if (m_shouldBypassAudioFlushOnSampleReplacementQuirk)
+        return m_shouldBypassAudioFlushOnSampleReplacementQuirk.value();
+
+    auto domain = m_document->securityOrigin().domain().convertToASCIILowercase();
+
+    m_shouldBypassAudioFlushOnSampleReplacementQuirk =
+        (domain.endsWith(".spotify.com"_s) || domain == "tv.scdn.co"_s);
+
+    return m_shouldBypassAudioFlushOnSampleReplacementQuirk.value();
+}
+#endif
+
 }

Source/WebCore/page/Quirks.h

@@ -207,6 +207,10 @@ class Quirks {
     bool needsRelaxedCorsMixedContentCheckQuirk() const;
     bool needsLaxSameSiteCookieQuirk(const URL&) const;
 
+#if ENABLE(MEDIA_SOURCE)
+    bool shouldBypassAudioFlushOnSampleReplacement() const;
+#endif
+
 private:
     bool needsQuirks() const;
     bool isDomain(const String&) const;
@@ -283,6 +287,9 @@ class Quirks {
     mutable std::optional<bool> m_needsYouTubeDarkModeQuirk;
 
     Vector<RegistrableDomain> m_subFrameDomainsForStorageAccessQuirk;
+#if ENABLE(MEDIA_SOURCE)
+    mutable std::optional<bool> m_shouldBypassAudioFlushOnSampleReplacementQuirk;
+#endif
 };
 
 } // namespace WebCore

Source/WebCore/platform/graphics/SourceBufferPrivate.cpp

@@ -1152,7 +1152,7 @@ bool SourceBufferPrivate::processMediaSample(SourceBufferPrivateClient& client,
             // Only force the TrackBuffer to re-enqueue if the removed ranges overlap with enqueued and possibly
             // not yet displayed samples.
             MediaTime currentTime = this->currentTime();
-            if (trackBuffer.highestEnqueuedPresentationTime().isValid() && currentTime < trackBuffer.highestEnqueuedPresentationTime()) {
+            if (trackBuffer.highestEnqueuedPresentationTime().isValid() && currentTime < trackBuffer.highestEnqueuedPresentationTime() && (!hasAudio() || !m_shouldBypassAudioFlushOnSampleReplacement)) {
                 PlatformTimeRanges possiblyEnqueuedRanges(currentTime, trackBuffer.highestEnqueuedPresentationTime());
                 possiblyEnqueuedRanges.intersectWith(erasedRanges);
                 if (possiblyEnqueuedRanges.length())

Source/WebCore/platform/graphics/SourceBufferPrivate.h

@@ -165,6 +165,7 @@ class SourceBufferPrivate
     virtual void attemptToDecrypt() { }
 #endif
 
+    void setShouldBypassAudioFlushOnSampleReplacement(bool flag) { m_shouldBypassAudioFlushOnSampleReplacement = flag; }
 protected:
     WEBCORE_EXPORT explicit SourceBufferPrivate(MediaSourcePrivate&, RefCountedSerialFunctionDispatcher&);
     MediaTime currentTime() const;
@@ -275,6 +276,8 @@ class SourceBufferPrivate
     MediaTime m_groupEndTimestamp { MediaTime::zeroTime() };
 
     bool m_isMediaSourceEnded { false };
+
+    bool m_shouldBypassAudioFlushOnSampleReplacement { false };
 };
 
 } // namespace WebCore