LibWeb: Add ChannelSplitterNode interface

Author: https://github.com/tcl3
Commit: https://github.com/LadybirdBrowser/ladybird/commit/e564d25ffb6
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3097
Reviewed-by: https://github.com/shannonbooth ✅

Libraries/LibWeb/CMakeLists.txt

@@ -793,6 +793,7 @@ set(SOURCES
     WebAudio/BaseAudioContext.cpp
     WebAudio/BiquadFilterNode.cpp
     WebAudio/ChannelMergerNode.cpp
+    WebAudio/ChannelSplitterNode.cpp
     WebAudio/DynamicsCompressorNode.cpp
     WebAudio/GainNode.cpp
     WebAudio/OfflineAudioContext.cpp

Libraries/LibWeb/WebAudio/AudioNode.h

@@ -65,7 +65,7 @@ public:
 
     virtual WebIDL::ExceptionOr<void> set_channel_count_mode(Bindings::ChannelCountMode);
     Bindings::ChannelCountMode channel_count_mode();
-    WebIDL::ExceptionOr<void> set_channel_interpretation(Bindings::ChannelInterpretation);
+    virtual WebIDL::ExceptionOr<void> set_channel_interpretation(Bindings::ChannelInterpretation);
     Bindings::ChannelInterpretation channel_interpretation();
 
     WebIDL::ExceptionOr<void> initialize_audio_node_options(AudioNodeOptions const& given_options, AudioNodeDefaultOptions const& default_options);

Libraries/LibWeb/WebAudio/ChannelSplitterNode.cpp

@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/ChannelSplitterNodePrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/WebAudio/BaseAudioContext.h>
+#include <LibWeb/WebAudio/ChannelSplitterNode.h>
+
+namespace Web::WebAudio {
+
+GC_DEFINE_ALLOCATOR(ChannelSplitterNode);
+
+ChannelSplitterNode::ChannelSplitterNode(JS::Realm& realm, GC::Ref<BaseAudioContext> context, ChannelSplitterOptions const& options)
+    : AudioNode(realm, context)
+    , m_number_of_outputs(options.number_of_outputs)
+{
+}
+
+ChannelSplitterNode::~ChannelSplitterNode() = default;
+
+WebIDL::ExceptionOr<GC::Ref<ChannelSplitterNode>> ChannelSplitterNode::create(JS::Realm& realm, GC::Ref<BaseAudioContext> context, ChannelSplitterOptions const& options)
+{
+    return construct_impl(realm, context, options);
+}
+
+WebIDL::ExceptionOr<GC::Ref<ChannelSplitterNode>> ChannelSplitterNode::construct_impl(JS::Realm& realm, GC::Ref<BaseAudioContext> context, ChannelSplitterOptions const& options)
+{
+    // https://webaudio.github.io/web-audio-api/#dom-baseaudiocontext-createchannelsplitter
+    // An IndexSizeError exception MUST be thrown if numberOfOutputs is less than 1 or is greater than the number of supported channels.
+    if (options.number_of_outputs < 1 || options.number_of_outputs > BaseAudioContext::MAX_NUMBER_OF_CHANNELS)
+        return WebIDL::IndexSizeError::create(realm, "Invalid number of outputs"_string);
+
+    auto node = realm.create<ChannelSplitterNode>(realm, context, options);
+
+    // Default options for channel count and interpretation
+    // https://webaudio.github.io/web-audio-api/#ChannelSplitterNode
+    AudioNodeDefaultOptions default_options;
+    default_options.channel_count_mode = Bindings::ChannelCountMode::Explicit;
+    default_options.channel_interpretation = Bindings::ChannelInterpretation::Discrete;
+    default_options.channel_count = node->number_of_outputs();
+    // FIXME: Set tail-time to no
+
+    TRY(node->initialize_audio_node_options(options, default_options));
+
+    return node;
+}
+
+void ChannelSplitterNode::initialize(JS::Realm& realm)
+{
+    AudioNode::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(ChannelSplitterNode);
+}
+
+WebIDL::ExceptionOr<void> ChannelSplitterNode::set_channel_count(WebIDL::UnsignedLong channel_count)
+{
+    // https://webaudio.github.io/web-audio-api/#audionode-channelcount-constraints
+    // The channel count cannot be changed, and an InvalidStateError exception MUST be thrown for any attempt to change the value.
+    if (channel_count != m_number_of_outputs)
+        return WebIDL::InvalidStateError::create(realm(), "Channel count must be equal to number of outputs"_string);
+
+    return AudioNode::set_channel_count(channel_count);
+}
+
+WebIDL::ExceptionOr<void> ChannelSplitterNode::set_channel_count_mode(Bindings::ChannelCountMode channel_count_mode)
+{
+    // https://webaudio.github.io/web-audio-api/#audionode-channelcountmode-constraints
+    // The channel count mode cannot be changed from "explicit" and an InvalidStateError exception MUST be thrown for any attempt to change the value.
+    if (channel_count_mode != Bindings::ChannelCountMode::Explicit)
+        return WebIDL::InvalidStateError::create(realm(), "Channel count mode must be 'explicit'"_string);
+
+    return AudioNode::set_channel_count_mode(channel_count_mode);
+}
+
+WebIDL::ExceptionOr<void> ChannelSplitterNode::set_channel_interpretation(Bindings::ChannelInterpretation channel_interpretation)
+{
+    // https://webaudio.github.io/web-audio-api/#audionode-channelinterpretation-constraints
+    // The channel intepretation can not be changed from "discrete" and a InvalidStateError exception MUST be thrown for any attempt to change the value.
+    if (channel_interpretation != Bindings::ChannelInterpretation::Discrete)
+        return WebIDL::InvalidStateError::create(realm(), "Channel interpretation must be 'discrete'"_string);
+
+    return AudioNode::set_channel_interpretation(channel_interpretation);
+}
+
+}

Libraries/LibWeb/WebAudio/ChannelSplitterNode.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/WebAudio/AudioNode.h>
+
+namespace Web::WebAudio {
+
+// https://webaudio.github.io/web-audio-api/#ChannelSplitterOptions
+struct ChannelSplitterOptions : AudioNodeOptions {
+    WebIDL::UnsignedLong number_of_outputs { 6 };
+};
+
+/// https://webaudio.github.io/web-audio-api/#ChannelSplitterNode
+class ChannelSplitterNode final : public AudioNode {
+    WEB_PLATFORM_OBJECT(ChannelSplitterNode, AudioNode);
+    GC_DECLARE_ALLOCATOR(ChannelSplitterNode);
+
+public:
+    virtual ~ChannelSplitterNode() override;
+
+    static WebIDL::ExceptionOr<GC::Ref<ChannelSplitterNode>> create(JS::Realm&, GC::Ref<BaseAudioContext>, ChannelSplitterOptions const& = {});
+    static WebIDL::ExceptionOr<GC::Ref<ChannelSplitterNode>> construct_impl(JS::Realm&, GC::Ref<BaseAudioContext>, ChannelSplitterOptions const& = {});
+
+    virtual WebIDL::UnsignedLong number_of_inputs() override { return 1; }
+    virtual WebIDL::UnsignedLong number_of_outputs() override { return m_number_of_outputs; }
+
+    virtual WebIDL::ExceptionOr<void> set_channel_count(WebIDL::UnsignedLong) override;
+    virtual WebIDL::ExceptionOr<void> set_channel_count_mode(Bindings::ChannelCountMode) override;
+    virtual WebIDL::ExceptionOr<void> set_channel_interpretation(Bindings::ChannelInterpretation) override;
+
+private:
+    ChannelSplitterNode(JS::Realm&, GC::Ref<BaseAudioContext>, ChannelSplitterOptions const&);
+
+    virtual void initialize(JS::Realm&) override;
+
+    WebIDL::UnsignedLong m_number_of_outputs;
+};
+
+}

Libraries/LibWeb/WebAudio/ChannelSplitterNode.idl

@@ -0,0 +1,13 @@
+#import <WebAudio/AudioNode.idl>
+#import <WebAudio/BaseAudioContext.idl>
+
+// https://webaudio.github.io/web-audio-api/#ChannelSplitterNode
+[Exposed=Window]
+interface ChannelSplitterNode : AudioNode {
+    constructor (BaseAudioContext context, optional ChannelSplitterOptions options = {});
+};
+
+// https://webaudio.github.io/web-audio-api/#ChannelSplitterOptions
+dictionary ChannelSplitterOptions : AudioNodeOptions {
+    unsigned long numberOfOutputs = 6;
+};

Libraries/LibWeb/idl_files.cmake

@@ -370,6 +370,7 @@ libweb_js_bindings(WebAudio/BiquadFilterNode)
 libweb_js_bindings(WebAudio/DynamicsCompressorNode)
 libweb_js_bindings(WebAudio/GainNode)
 libweb_js_bindings(WebAudio/ChannelMergerNode)
+libweb_js_bindings(WebAudio/ChannelSplitterNode)
 libweb_js_bindings(WebAudio/OfflineAudioContext)
 libweb_js_bindings(WebAudio/OscillatorNode)
 libweb_js_bindings(WebAudio/PannerNode)

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

@@ -57,6 +57,7 @@ CanvasGradient
 CanvasPattern
 CanvasRenderingContext2D
 ChannelMergerNode
+ChannelSplitterNode
 CharacterData
 Clipboard
 ClipboardEvent

Tests/LibWeb/Text/expected/wpt-import/webaudio/the-audio-api/the-channelsplitternode-interface/ctor-channelsplitter.txt

@@ -0,0 +1,52 @@
+Harness status: OK
+
+Found 47 tests
+
+47 Pass
+Pass	# AUDIT TASK RUNNER STARTED.
+Pass	Executing "initialize"
+Pass	Executing "invalid constructor"
+Pass	Executing "default constructor"
+Pass	Executing "test AudioNodeOptions"
+Pass	Executing "constructor options"
+Pass	Audit report
+Pass	> [initialize] 
+Pass	  context = new OfflineAudioContext(...) did not throw an exception.
+Pass	< [initialize] All assertions passed. (total 1 assertions)
+Pass	> [invalid constructor] 
+Pass	  new ChannelSplitterNode() threw TypeError: "ChannelSplitterNode() needs one argument".
+Pass	  new ChannelSplitterNode(1) threw TypeError: "Not an object of type BaseAudioContext".
+Pass	  new ChannelSplitterNode(context, 42) threw TypeError: "Not an object of type ChannelSplitterOptions".
+Pass	< [invalid constructor] All assertions passed. (total 3 assertions)
+Pass	> [default constructor] 
+Pass	  node0 = new ChannelSplitterNode(context) did not throw an exception.
+Pass	  node0 instanceof ChannelSplitterNode is equal to true.
+Pass	  node0.numberOfInputs is equal to 1.
+Pass	  node0.numberOfOutputs is equal to 6.
+Pass	  node0.channelCount is equal to 6.
+Pass	  node0.channelCountMode is equal to explicit.
+Pass	  node0.channelInterpretation is equal to discrete.
+Pass	< [default constructor] All assertions passed. (total 7 assertions)
+Pass	> [test AudioNodeOptions] 
+Pass	  new ChannelSplitterNode(c, {channelCount: 6}) did not throw an exception.
+Pass	  node.channelCount is equal to 6.
+Pass	  new ChannelSplitterNode(c, {channelCount: 7}) threw InvalidStateError: "Channel count must be equal to number of outputs".
+Pass	  (new ChannelSplitterNode(c, {channelCount: 6})).channelCount = 6 did not throw an exception.
+Pass	  new ChannelSplitterNode(c, {channelCountMode: "explicit"} did not throw an exception.
+Pass	  node.channelCountMode is equal to explicit.
+Pass	  new ChannelSplitterNode(c, {channelCountMode: "max"}) threw InvalidStateError: "Channel count mode must be 'explicit'".
+Pass	  new ChannelSplitterNode(c, {channelCountMode: "clamped-max"}) threw InvalidStateError: "Channel count mode must be 'explicit'".
+Pass	  (new ChannelSplitterNode(c, {channelCountMode: "explicit"})).channelCountMode = "explicit" did not throw an exception.
+Pass	  new ChannelSplitterNode(c, {channelInterpretation: "speakers"}) threw InvalidStateError: "Channel interpretation must be 'discrete'".
+Pass	  (new ChannelSplitterNode(c, {channelInterpretation: "discrete"})).channelInterpretation = "discrete" did not throw an exception.
+Pass	< [test AudioNodeOptions] All assertions passed. (total 11 assertions)
+Pass	> [constructor options] 
+Pass	  node1 = new ChannelSplitterNode(context, {"numberOfInputs":3,"numberOfOutputs":9,"channelInterpretation":"discrete"}) did not throw an exception.
+Pass	  node1.numberOfInputs is equal to 1.
+Pass	  node1.numberOfOutputs is equal to 9.
+Pass	  node1.channelInterpretation is equal to discrete.
+Pass	  new ChannelSplitterNode(c, {"numberOfOutputs":99}) threw IndexSizeError: "Invalid number of outputs".
+Pass	  new ChannelSplitterNode(c, {"channelCount":3}) threw InvalidStateError: "Channel count must be equal to number of outputs".
+Pass	  new ChannelSplitterNode(c, {"channelCountMode":"max"}) threw InvalidStateError: "Channel count mode must be 'explicit'".
+Pass	< [constructor options] All assertions passed. (total 7 assertions)
+Pass	# AUDIT TASK RUNNER FINISHED: 5 tasks ran successfully.

Tests/LibWeb/Text/input/wpt-import/webaudio/the-audio-api/the-channelsplitternode-interface/ctor-channelsplitter.html

@@ -0,0 +1,115 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>
+      Test Constructor: ChannelSplitter
+    </title>
+    <script src="../../../resources/testharness.js"></script>
+    <script src="../../../resources/testharnessreport.js"></script>
+    <script src="../../../webaudio/resources/audit-util.js"></script>
+    <script src="../../../webaudio/resources/audit.js"></script>
+    <script src="../../../webaudio/resources/audionodeoptions.js"></script>
+  </head>
+  <body>
+    <script id="layout-test-code">
+      let context;
+
+      let audit = Audit.createTaskRunner();
+
+      audit.define('initialize', (task, should) => {
+        context = initializeContext(should);
+        task.done();
+      });
+
+      audit.define('invalid constructor', (task, should) => {
+        testInvalidConstructor(should, 'ChannelSplitterNode', context);
+        task.done();
+      });
+
+      audit.define('default constructor', (task, should) => {
+        testDefaultConstructor(should, 'ChannelSplitterNode', context, {
+          prefix: 'node0',
+          numberOfInputs: 1,
+          numberOfOutputs: 6,
+          channelCount: 6,
+          channelCountMode: 'explicit',
+          channelInterpretation: 'discrete'
+        });
+
+        task.done();
+      });
+
+      audit.define('test AudioNodeOptions', (task, should) => {
+        testAudioNodeOptions(should, context, 'ChannelSplitterNode', {
+          channelCount: {
+            value: 6,
+            isFixed: true,
+            exceptionType: 'InvalidStateError'
+          },
+          channelCountMode: {
+            value: 'explicit',
+            isFixed: true,
+            exceptionType: 'InvalidStateError'
+          },
+          channelInterpretation: {
+            value: 'discrete',
+            isFixed: true,
+            exceptionType: 'InvalidStateError'
+          },
+        });
+        task.done();
+      });
+
+      audit.define('constructor options', (task, should) => {
+        let node;
+        let options = {
+          numberOfInputs: 3,
+          numberOfOutputs: 9,
+          channelInterpretation: 'discrete'
+        };
+
+        should(
+            () => {
+              node = new ChannelSplitterNode(context, options);
+            },
+            'node1 = new ChannelSplitterNode(context, ' +
+                JSON.stringify(options) + ')')
+            .notThrow();
+
+        should(node.numberOfInputs, 'node1.numberOfInputs').beEqualTo(1);
+        should(node.numberOfOutputs, 'node1.numberOfOutputs')
+            .beEqualTo(options.numberOfOutputs);
+        should(node.channelInterpretation, 'node1.channelInterpretation')
+            .beEqualTo(options.channelInterpretation);
+
+        options = {numberOfOutputs: 99};
+        should(
+            () => {
+              node = new ChannelSplitterNode(context, options);
+            },
+            'new ChannelSplitterNode(c, ' + JSON.stringify(options) + ')')
+            .throw(DOMException, 'IndexSizeError');
+
+        options = {channelCount: 3};
+        should(
+            () => {
+              node = new ChannelSplitterNode(context, options);
+            },
+            'new ChannelSplitterNode(c, ' + JSON.stringify(options) + ')')
+            .throw(DOMException, 'InvalidStateError');
+
+        options = {channelCountMode: 'max'};
+        should(
+            () => {
+              node = new ChannelSplitterNode(context, options);
+            },
+            'new ChannelSplitterNode(c, ' + JSON.stringify(options) + ')')
+            .throw(DOMException, 'InvalidStateError');
+
+        task.done();
+      });
+
+      audit.run();
+    </script>
+  </body>
+</html>