1 files changed, 105 insertions, 0 deletions
diff --git a/dom/media/webaudio/ChannelSplitterNode.cpp b/dom/media/webaudio/ChannelSplitterNode.cpp
new file mode 100644
index 0000000000..52d3ae948f
--- /dev/null
+++ b/dom/media/webaudio/ChannelSplitterNode.cpp
@@ -0,0 +1,105 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/ChannelSplitterNode.h"
+#include "mozilla/dom/ChannelSplitterNodeBinding.h"
+#include "AudioNodeEngine.h"
+#include "AudioNodeTrack.h"
+#include "Tracing.h"
+
+namespace mozilla::dom {
+
+class ChannelSplitterNodeEngine final : public AudioNodeEngine {
+ public:
+  explicit ChannelSplitterNodeEngine(ChannelSplitterNode* aNode)
+      : AudioNodeEngine(aNode) {
+    MOZ_ASSERT(NS_IsMainThread());
+  }
+
+  void ProcessBlocksOnPorts(AudioNodeTrack* aTrack, GraphTime aFrom,
+                            Span<const AudioBlock> aInput,
+                            Span<AudioBlock> aOutput,
+                            bool* aFinished) override {
+    MOZ_ASSERT(aInput.Length() == 1, "Should only have one input port");
+    MOZ_ASSERT(aOutput.Length() == OutputCount());
+    TRACE("ChannelSplitterNodeEngine::ProcessBlocksOnPorts");
+
+    for (uint16_t i = 0; i < OutputCount(); ++i) {
+      if (i < aInput[0].ChannelCount()) {
+        // Split out existing channels
+        aOutput[i].AllocateChannels(1);
+        AudioBlockCopyChannelWithScale(
+            static_cast<const float*>(aInput[0].mChannelData[i]),
+            aInput[0].mVolume, aOutput[i].ChannelFloatsForWrite(0));
+      } else {
+        // Pad with silent channels if needed
+        aOutput[i].SetNull(WEBAUDIO_BLOCK_SIZE);
+      }
+    }
+  }
+
+  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override {
+    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+  }
+};
+
+ChannelSplitterNode::ChannelSplitterNode(AudioContext* aContext,
+                                         uint16_t aOutputCount)
+    : AudioNode(aContext, aOutputCount, ChannelCountMode::Explicit,
+                ChannelInterpretation::Discrete),
+      mOutputCount(aOutputCount) {
+  mTrack =
+      AudioNodeTrack::Create(aContext, new ChannelSplitterNodeEngine(this),
+                             AudioNodeTrack::NO_TRACK_FLAGS, aContext->Graph());
+}
+
+/* static */
+already_AddRefed<ChannelSplitterNode> ChannelSplitterNode::Create(
+    AudioContext& aAudioContext, const ChannelSplitterOptions& aOptions,
+    ErrorResult& aRv) {
+  if (aOptions.mNumberOfOutputs == 0 ||
+      aOptions.mNumberOfOutputs > WebAudioUtils::MaxChannelCount) {
+    aRv.ThrowIndexSizeError(nsPrintfCString(
+        "%u is not a valid number of outputs", aOptions.mNumberOfOutputs));
+    return nullptr;
+  }
+
+  RefPtr<ChannelSplitterNode> audioNode =
+      new ChannelSplitterNode(&aAudioContext, aOptions.mNumberOfOutputs);
+
+  // Manually check that the other options are valid, this node has
+  // channelCount, channelCountMode and channelInterpretation constraints: they
+  // cannot be changed from the default.
+  if (aOptions.mChannelCount.WasPassed()) {
+    audioNode->SetChannelCount(aOptions.mChannelCount.Value(), aRv);
+    if (aRv.Failed()) {
+      return nullptr;
+    }
+  }
+  if (aOptions.mChannelInterpretation.WasPassed()) {
+    audioNode->SetChannelInterpretationValue(
+        aOptions.mChannelInterpretation.Value(), aRv);
+    if (aRv.Failed()) {
+      return nullptr;
+    }
+  }
+  if (aOptions.mChannelCountMode.WasPassed()) {
+    audioNode->SetChannelCountModeValue(aOptions.mChannelCountMode.Value(),
+                                        aRv);
+    if (aRv.Failed()) {
+      return nullptr;
+    }
+  }
+
+  return audioNode.forget();
+}
+
+JSObject* ChannelSplitterNode::WrapObject(JSContext* aCx,
+                                          JS::Handle<JSObject*> aGivenProto) {
+  return ChannelSplitterNode_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+}  // namespace mozilla::dom