LibWeb: Add stubbed Media Source Extensions API

Just the boilerplate :^)

Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp

@@ -90,10 +90,12 @@ static bool is_platform_object(Type const& type)
         "ServiceWorkerRegistration"sv,
         "SVGTransform"sv,
         "ShadowRoot"sv,
+        "SourceBuffer"sv,
         "Table"sv,
         "Text"sv,
         "TextMetrics"sv,
         "TextTrack"sv,
+        "TimeRanges"sv,
         "URLSearchParams"sv,
         "VTTRegion"sv,
         "VideoTrack"sv,
@@ -4240,6 +4242,7 @@ static void generate_using_namespace_definitions(SourceGenerator& generator)
     using namespace Web::Internals;
     using namespace Web::IntersectionObserver;
     using namespace Web::MediaCapabilitiesAPI;
+    using namespace Web::MediaSourceExtensions;
     using namespace Web::NavigationTiming;
     using namespace Web::PerformanceTimeline;
     using namespace Web::RequestIdleCallback;

Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/Namespaces.h

@@ -28,6 +28,7 @@ static constexpr Array libweb_interface_namespaces = {
     "Internals"sv,
     "IntersectionObserver"sv,
     "MathML"sv,
+    "MediaSourceExtensions"sv,
     "NavigationTiming"sv,
     "RequestIdleCallback"sv,
     "ResizeObserver"sv,

Meta/gn/secondary/Userland/Libraries/LibWeb/BUILD.gn

@@ -319,6 +319,7 @@ shared_library("LibWeb") {
            "Loader",
            "MathML",
            "MediaCapabilitiesAPI",
+           "MediaSourceExtensions",
            "MimeSniff",
            "MixedContent",
            "NavigationTiming",

Meta/gn/secondary/Userland/Libraries/LibWeb/MediaSourceExtensions/BUILD.gn

@@ -0,0 +1,13 @@
+source_set("MediaSourceExtensions") {
+  configs += [ "//Userland/Libraries/LibWeb:configs" ]
+  deps = [ "//Userland/Libraries/LibWeb:all_generated" ]
+  sources = [
+    "BufferedChangeEvent.cpp",
+    "ManagedMediaSource.cpp",
+    "ManagedSourceBuffer.cpp",
+    "MediaSource.cpp",
+    "MediaSourceHandle.cpp",
+    "SourceBuffer.cpp",
+    "SourceBufferList.cpp",
+  ]
+}

Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni

@@ -268,6 +268,13 @@ standard_idl_files = [
   "//Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserverEntry.idl",
   "//Userland/Libraries/LibWeb/MathML/MathMLElement.idl",
   "//Userland/Libraries/LibWeb/MediaCapabilitiesAPI/MediaCapabilities.idl",
+  "//Userland/Libraries/LibWeb/MediaSourceExtensions/BufferedChangeEvent.idl",
+  "//Userland/Libraries/LibWeb/MediaSourceExtensions/ManagedMediaSource.idl",
+  "//Userland/Libraries/LibWeb/MediaSourceExtensions/ManagedSourceBuffer.idl",
+  "//Userland/Libraries/LibWeb/MediaSourceExtensions/MediaSource.idl",
+  "//Userland/Libraries/LibWeb/MediaSourceExtensions/MediaSourceHandle.idl",
+  "//Userland/Libraries/LibWeb/MediaSourceExtensions/SourceBuffer.idl",
+  "//Userland/Libraries/LibWeb/MediaSourceExtensions/SourceBufferList.idl",
   "//Userland/Libraries/LibWeb/NavigationTiming/PerformanceTiming.idl",
   "//Userland/Libraries/LibWeb/NavigationTiming/PerformanceNavigation.idl",
   "//Userland/Libraries/LibWeb/PerformanceTimeline/PerformanceEntry.idl",

Tests/LibWeb/Text/expected/all-window-properties.txt

@@ -30,6 +30,7 @@ BiquadFilterNode
 Blob
 Boolean
 BroadcastChannel
+BufferedChangeEvent
 ByteLengthQueuingStrategy
 CDATASection
 CSSAnimation
@@ -212,6 +213,8 @@ Iterator
 KeyboardEvent
 KeyframeEffect
 Location
+ManagedMediaSource
+ManagedSourceBuffer
 Map
 MathMLElement
 MediaCapabilities
@@ -219,6 +222,8 @@ MediaError
 MediaList
 MediaQueryList
 MediaQueryListEvent
+MediaSource
+MediaSourceHandle
 MessageChannel
 MessageEvent
 MessagePort
@@ -335,6 +340,8 @@ Set
 ShadowRealm
 ShadowRoot
 SharedArrayBuffer
+SourceBuffer
+SourceBufferList
 StaticRange
 Storage
 StorageManager

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -563,6 +563,13 @@ set(SOURCES
     MathML/MathMLElement.cpp
     MathML/TagNames.cpp
     MediaCapabilitiesAPI/MediaCapabilities.cpp
+    MediaSourceExtensions/BufferedChangeEvent.cpp
+    MediaSourceExtensions/ManagedMediaSource.cpp
+    MediaSourceExtensions/ManagedSourceBuffer.cpp
+    MediaSourceExtensions/MediaSource.cpp
+    MediaSourceExtensions/MediaSourceHandle.cpp
+    MediaSourceExtensions/SourceBuffer.cpp
+    MediaSourceExtensions/SourceBufferList.cpp
     MimeSniff/MimeType.cpp
     MimeSniff/Resource.cpp
     MixedContent/AbstractOperations.cpp

Userland/Libraries/LibWeb/Forward.h

@@ -623,6 +623,16 @@ namespace Web::MediaCapabilitiesAPI {
 class MediaCapabilities;
 }
 
+namespace Web::MediaSourceExtensions {
+class BufferedChangeEvent;
+class ManagedMediaSource;
+class ManagedSourceBuffer;
+class MediaSource;
+class MediaSourceHandle;
+class SourceBuffer;
+class SourceBufferList;
+}
+
 namespace Web::MimeSniff {
 class MimeType;
 }

Userland/Libraries/LibWeb/MediaSourceExtensions/BufferedChangeEvent.cpp

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/BufferedChangeEventPrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/MediaSourceExtensions/BufferedChangeEvent.h>
+
+namespace Web::MediaSourceExtensions {
+
+JS_DEFINE_ALLOCATOR(BufferedChangeEvent);
+
+WebIDL::ExceptionOr<JS::NonnullGCPtr<BufferedChangeEvent>> BufferedChangeEvent::construct_impl(JS::Realm& realm, AK::FlyString const& type, BufferedChangeEventInit const& event_init)
+{
+    return realm.heap().allocate<BufferedChangeEvent>(realm, realm, type, event_init);
+}
+
+BufferedChangeEvent::BufferedChangeEvent(JS::Realm& realm, AK::FlyString const& type, BufferedChangeEventInit const&)
+    : DOM::Event(realm, type)
+{
+}
+
+BufferedChangeEvent::~BufferedChangeEvent() = default;
+
+void BufferedChangeEvent::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(BufferedChangeEvent);
+}
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/BufferedChangeEvent.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/DOM/Event.h>
+#include <LibWeb/HTML/TimeRanges.h>
+
+namespace Web::MediaSourceExtensions {
+
+struct BufferedChangeEventInit : public DOM::EventInit {
+    JS::GCPtr<HTML::TimeRanges> added_ranges;
+    JS::GCPtr<HTML::TimeRanges> removed_ranges;
+};
+
+// https://w3c.github.io/media-source/#bufferedchangeevent-interface
+class BufferedChangeEvent : public DOM::Event {
+    WEB_PLATFORM_OBJECT(BufferedChangeEvent, DOM::Event);
+    JS_DECLARE_ALLOCATOR(BufferedChangeEvent);
+
+public:
+    [[nodiscard]] static WebIDL::ExceptionOr<JS::NonnullGCPtr<BufferedChangeEvent>> construct_impl(JS::Realm&, FlyString const& type, BufferedChangeEventInit const& = {});
+
+private:
+    BufferedChangeEvent(JS::Realm&, FlyString const& type, BufferedChangeEventInit const& event_init);
+
+    virtual ~BufferedChangeEvent() override;
+
+    virtual void initialize(JS::Realm&) override;
+};
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/BufferedChangeEvent.idl

@@ -0,0 +1,17 @@
+#import <DOM/Event.idl>
+#import <HTML/TimeRanges.idl>
+
+// https://w3c.github.io/media-source/#dom-bufferedchangeevent
+[Exposed=(Window,DedicatedWorker)]
+interface BufferedChangeEvent : Event {
+    constructor(DOMString type, optional BufferedChangeEventInit eventInitDict = {});
+
+    [FIXME,SameObject] readonly attribute TimeRanges addedRanges;
+    [FIXME,SameObject] readonly attribute TimeRanges removedRanges;
+};
+
+// https://w3c.github.io/media-source/#dom-bufferedchangeeventinit
+dictionary BufferedChangeEventInit : EventInit {
+    TimeRanges addedRanges;
+    TimeRanges removedRanges;
+};

Userland/Libraries/LibWeb/MediaSourceExtensions/ManagedMediaSource.cpp

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Bindings/ManagedMediaSourcePrototype.h>
+#include <LibWeb/MediaSourceExtensions/ManagedMediaSource.h>
+
+namespace Web::MediaSourceExtensions {
+
+JS_DEFINE_ALLOCATOR(ManagedMediaSource);
+
+WebIDL::ExceptionOr<JS::NonnullGCPtr<ManagedMediaSource>> ManagedMediaSource::construct_impl(JS::Realm& realm)
+{
+    return realm.heap().allocate<ManagedMediaSource>(realm, realm);
+}
+
+ManagedMediaSource::ManagedMediaSource(JS::Realm& realm)
+    : MediaSource(realm)
+{
+}
+
+ManagedMediaSource::~ManagedMediaSource() = default;
+
+void ManagedMediaSource::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(ManagedMediaSource);
+}
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/ManagedMediaSource.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/MediaSourceExtensions/MediaSource.h>
+
+namespace Web::MediaSourceExtensions {
+
+// https://w3c.github.io/media-source/#managedmediasource-interface
+class ManagedMediaSource : public MediaSource {
+    WEB_PLATFORM_OBJECT(ManagedMediaSource, MediaSource);
+    JS_DECLARE_ALLOCATOR(ManagedMediaSource);
+
+public:
+    [[nodiscard]] static WebIDL::ExceptionOr<JS::NonnullGCPtr<ManagedMediaSource>> construct_impl(JS::Realm&);
+
+private:
+    ManagedMediaSource(JS::Realm&);
+
+    virtual ~ManagedMediaSource() override;
+
+    virtual void initialize(JS::Realm&) override;
+};
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/ManagedMediaSource.idl

@@ -0,0 +1,11 @@
+#import <DOM/EventHandler.idl>
+#import <MediaSourceExtensions/MediaSource.idl>
+
+// https://w3c.github.io/media-source/#managedmediasource-interface
+[Exposed=(Window,DedicatedWorker)]
+interface ManagedMediaSource : MediaSource {
+    constructor();
+    [FIXME] readonly attribute boolean streaming;
+    [FIXME] attribute EventHandler onstartstreaming;
+    [FIXME] attribute EventHandler onendstreaming;
+};

Userland/Libraries/LibWeb/MediaSourceExtensions/ManagedSourceBuffer.cpp

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Bindings/ManagedSourceBufferPrototype.h>
+#include <LibWeb/MediaSourceExtensions/ManagedSourceBuffer.h>
+
+namespace Web::MediaSourceExtensions {
+
+JS_DEFINE_ALLOCATOR(ManagedSourceBuffer);
+
+ManagedSourceBuffer::ManagedSourceBuffer(JS::Realm& realm)
+    : SourceBuffer(realm)
+{
+}
+
+ManagedSourceBuffer::~ManagedSourceBuffer() = default;
+
+void ManagedSourceBuffer::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(ManagedSourceBuffer);
+}
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/ManagedSourceBuffer.h

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/MediaSourceExtensions/SourceBuffer.h>
+
+namespace Web::MediaSourceExtensions {
+
+// https://w3c.github.io/media-source/#managedsourcebuffer-interface
+class ManagedSourceBuffer : public SourceBuffer {
+    WEB_PLATFORM_OBJECT(ManagedSourceBuffer, SourceBuffer);
+    JS_DECLARE_ALLOCATOR(ManagedSourceBuffer);
+
+public:
+private:
+    ManagedSourceBuffer(JS::Realm&);
+
+    virtual ~ManagedSourceBuffer() override;
+
+    virtual void initialize(JS::Realm&) override;
+};
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/ManagedSourceBuffer.idl

@@ -0,0 +1,8 @@
+#import <DOM/EventHandler.idl>
+#import <MediaSourceExtensions/SourceBuffer.idl>
+
+// https://w3c.github.io/media-source/#managedsourcebuffer-interface
+[Exposed=(Window,DedicatedWorker)]
+interface ManagedSourceBuffer : SourceBuffer {
+    [FIXME] attribute EventHandler onbufferedchange;
+};

Userland/Libraries/LibWeb/MediaSourceExtensions/MediaSource.cpp

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Bindings/MediaSourcePrototype.h>
+#include <LibWeb/MediaSourceExtensions/MediaSource.h>
+
+namespace Web::MediaSourceExtensions {
+
+JS_DEFINE_ALLOCATOR(MediaSource);
+
+WebIDL::ExceptionOr<JS::NonnullGCPtr<MediaSource>> MediaSource::construct_impl(JS::Realm& realm)
+{
+    return realm.heap().allocate<MediaSource>(realm, realm);
+}
+
+MediaSource::MediaSource(JS::Realm& realm)
+    : DOM::EventTarget(realm)
+{
+}
+
+MediaSource::~MediaSource() = default;
+
+void MediaSource::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(MediaSource);
+}
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/MediaSource.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/DOM/EventTarget.h>
+
+namespace Web::MediaSourceExtensions {
+
+// https://w3c.github.io/media-source/#dom-mediasource
+class MediaSource : public DOM::EventTarget {
+    WEB_PLATFORM_OBJECT(MediaSource, DOM::EventTarget);
+    JS_DECLARE_ALLOCATOR(MediaSource);
+
+public:
+    [[nodiscard]] static WebIDL::ExceptionOr<JS::NonnullGCPtr<MediaSource>> construct_impl(JS::Realm&);
+
+    // https://w3c.github.io/media-source/#dom-mediasource-canconstructindedicatedworker
+    static bool can_construct_in_dedicated_worker(JS::VM&) { return true; }
+
+protected:
+    MediaSource(JS::Realm&);
+
+    virtual ~MediaSource() override;
+
+    virtual void initialize(JS::Realm&) override;
+
+private:
+};
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/MediaSource.idl

@@ -0,0 +1,42 @@
+#import <DOM/EventHandler.idl>
+#import <MediaSourceExtensions/MediaSourceHandle.idl>
+#import <MediaSourceExtensions/SourceBufferList.idl>
+
+// https://w3c.github.io/media-source/#dom-mediasource
+enum ReadyState {
+    "closed",
+    "open",
+    "ended",
+};
+
+// https://w3c.github.io/media-source/#dom-mediasource
+enum EndOfStreamError {
+    "network",
+    "decode",
+};
+
+// https://w3c.github.io/media-source/#dom-mediasource
+[Exposed=(Window,DedicatedWorker)]
+interface MediaSource : EventTarget {
+    constructor();
+
+    [FIXME, SameObject, Exposed=DedicatedWorker]
+    readonly  attribute MediaSourceHandle handle;
+    [FIXME] readonly  attribute SourceBufferList sourceBuffers;
+    [FIXME] readonly  attribute SourceBufferList activeSourceBuffers;
+    [FIXME] readonly  attribute ReadyState readyState;
+
+    [FIXME] attribute unrestricted double duration;
+    [FIXME] attribute EventHandler onsourceopen;
+    [FIXME] attribute EventHandler onsourceended;
+    [FIXME] attribute EventHandler onsourceclose;
+
+    static readonly attribute boolean canConstructInDedicatedWorker;
+
+    [FIXME] SourceBuffer addSourceBuffer(DOMString type);
+    [FIXME] undefined removeSourceBuffer(SourceBuffer sourceBuffer);
+    [FIXME] undefined endOfStream(optional EndOfStreamError error);
+    [FIXME] undefined setLiveSeekableRange(double start, double end);
+    [FIXME] undefined clearLiveSeekableRange();
+    [FIXME] static boolean isTypeSupported(DOMString type);
+};

Userland/Libraries/LibWeb/MediaSourceExtensions/MediaSourceHandle.cpp

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Bindings/MediaSourceHandlePrototype.h>
+#include <LibWeb/MediaSourceExtensions/MediaSourceHandle.h>
+
+namespace Web::MediaSourceExtensions {
+
+JS_DEFINE_ALLOCATOR(MediaSourceHandle);
+
+MediaSourceHandle::MediaSourceHandle(JS::Realm& realm)
+    : Bindings::PlatformObject(realm)
+{
+}
+
+MediaSourceHandle::~MediaSourceHandle() = default;
+
+void MediaSourceHandle::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(MediaSourceHandle);
+}
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/MediaSourceHandle.h

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/Bindings/PlatformObject.h>
+#include <LibWeb/WebIDL/ExceptionOr.h>
+
+namespace Web::MediaSourceExtensions {
+
+// https://w3c.github.io/media-source/#dom-mediasourcehandle
+class MediaSourceHandle : public Bindings::PlatformObject {
+    WEB_PLATFORM_OBJECT(MediaSourceHandle, Bindings::PlatformObject);
+    JS_DECLARE_ALLOCATOR(MediaSourceHandle);
+
+public:
+private:
+    MediaSourceHandle(JS::Realm&);
+
+    virtual ~MediaSourceHandle() override;
+
+    virtual void initialize(JS::Realm&) override;
+};
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/MediaSourceHandle.idl

@@ -0,0 +1,3 @@
+// https://w3c.github.io/media-source/#dom-mediasourcehandle
+[Transferable, Exposed=(Window,DedicatedWorker)]
+interface MediaSourceHandle {};

Userland/Libraries/LibWeb/MediaSourceExtensions/SourceBuffer.cpp

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Bindings/SourceBufferPrototype.h>
+#include <LibWeb/MediaSourceExtensions/SourceBuffer.h>
+
+namespace Web::MediaSourceExtensions {
+
+JS_DEFINE_ALLOCATOR(SourceBuffer);
+
+SourceBuffer::SourceBuffer(JS::Realm& realm)
+    : DOM::EventTarget(realm)
+{
+}
+
+SourceBuffer::~SourceBuffer() = default;
+
+void SourceBuffer::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(SourceBuffer);
+}
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/SourceBuffer.h

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/DOM/EventTarget.h>
+
+namespace Web::MediaSourceExtensions {
+
+// https://w3c.github.io/media-source/#dom-sourcebuffer
+class SourceBuffer : public DOM::EventTarget {
+    WEB_PLATFORM_OBJECT(SourceBuffer, DOM::EventTarget);
+    JS_DECLARE_ALLOCATOR(SourceBuffer);
+
+protected:
+    SourceBuffer(JS::Realm&);
+
+    virtual ~SourceBuffer() override;
+
+    virtual void initialize(JS::Realm&) override;
+
+private:
+};
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/SourceBuffer.idl

@@ -0,0 +1,36 @@
+#import <DOM/EventHandler.idl>
+#import <HTML/AudioTrackList.idl>
+#import <HTML/TextTrackList.idl>
+#import <HTML/VideoTrackList.idl>
+#import <HTML/TimeRanges.idl>
+
+// https://w3c.github.io/media-source/#dom-sourcebuffer
+enum AppendMode {
+    "segments",
+    "sequence",
+};
+
+// https://w3c.github.io/media-source/#dom-sourcebuffer
+[Exposed=(Window,DedicatedWorker)]
+interface SourceBuffer : EventTarget {
+    [FIXME] attribute AppendMode mode;
+    [FIXME] readonly  attribute boolean updating;
+    [FIXME] readonly  attribute TimeRanges buffered;
+    [FIXME] attribute double timestampOffset;
+    [FIXME] readonly  attribute AudioTrackList audioTracks;
+    [FIXME] readonly  attribute VideoTrackList videoTracks;
+    [FIXME] readonly  attribute TextTrackList textTracks;
+    [FIXME] attribute double appendWindowStart;
+    [FIXME] attribute unrestricted double appendWindowEnd;
+
+    [FIXME] attribute EventHandler onupdatestart;
+    [FIXME] attribute EventHandler onupdate;
+    [FIXME] attribute EventHandler onupdateend;
+    [FIXME] attribute EventHandler onerror;
+    [FIXME] attribute EventHandler onabort;
+
+    [FIXME] undefined appendBuffer(BufferSource data);
+    [FIXME] undefined abort();
+    [FIXME] undefined changeType(DOMString type);
+    [FIXME] undefined remove(double start, unrestricted double end);
+};

Userland/Libraries/LibWeb/MediaSourceExtensions/SourceBufferList.cpp

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Bindings/SourceBufferListPrototype.h>
+#include <LibWeb/MediaSourceExtensions/SourceBufferList.h>
+
+namespace Web::MediaSourceExtensions {
+
+JS_DEFINE_ALLOCATOR(SourceBufferList);
+
+SourceBufferList::SourceBufferList(JS::Realm& realm)
+    : DOM::EventTarget(realm)
+{
+}
+
+SourceBufferList::~SourceBufferList() = default;
+
+void SourceBufferList::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(SourceBufferList);
+}
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/SourceBufferList.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/DOM/EventTarget.h>
+
+namespace Web::MediaSourceExtensions {
+
+// https://w3c.github.io/media-source/#dom-sourcebufferlist
+class SourceBufferList : public DOM::EventTarget {
+    WEB_PLATFORM_OBJECT(SourceBufferList, DOM::EventTarget);
+    JS_DECLARE_ALLOCATOR(SourceBufferList);
+
+private:
+    SourceBufferList(JS::Realm&);
+
+    virtual ~SourceBufferList() override;
+
+    virtual void initialize(JS::Realm&) override;
+};
+
+}

Userland/Libraries/LibWeb/MediaSourceExtensions/SourceBufferList.idl

@@ -0,0 +1,13 @@
+#import <DOM/EventHandler.idl>
+#import <MediaSourceExtensions/SourceBuffer.idl>
+
+// https://w3c.github.io/media-source/#dom-sourcebufferlist
+[Exposed=(Window,DedicatedWorker)]
+interface SourceBufferList : EventTarget {
+    [FIXME] readonly attribute unsigned long length;
+
+    [FIXME] attribute EventHandler onaddsourcebuffer;
+    [FIXME] attribute EventHandler onremovesourcebuffer;
+
+    [FIXME] getter SourceBuffer (unsigned long index);
+};

Userland/Libraries/LibWeb/idl_files.cmake

@@ -252,6 +252,13 @@ libweb_js_bindings(IntersectionObserver/IntersectionObserver)
 libweb_js_bindings(IntersectionObserver/IntersectionObserverEntry)
 libweb_js_bindings(MathML/MathMLElement)
 libweb_js_bindings(MediaCapabilitiesAPI/MediaCapabilities)
+libweb_js_bindings(MediaSourceExtensions/BufferedChangeEvent)
+libweb_js_bindings(MediaSourceExtensions/ManagedMediaSource)
+libweb_js_bindings(MediaSourceExtensions/ManagedSourceBuffer)
+libweb_js_bindings(MediaSourceExtensions/MediaSource)
+libweb_js_bindings(MediaSourceExtensions/MediaSourceHandle)
+libweb_js_bindings(MediaSourceExtensions/SourceBuffer)
+libweb_js_bindings(MediaSourceExtensions/SourceBufferList)
 libweb_js_bindings(NavigationTiming/PerformanceNavigation)
 libweb_js_bindings(NavigationTiming/PerformanceTiming)
 libweb_js_bindings(PerformanceTimeline/PerformanceEntry)