1 files changed, 100 insertions, 0 deletions
diff --git a/dom/media/webaudio/ChannelMergerNode.cpp b/dom/media/webaudio/ChannelMergerNode.cpp
new file mode 100644
index 0000000000..4ffae02591
--- /dev/null
+++ b/dom/media/webaudio/ChannelMergerNode.cpp
@@ -0,0 +1,100 @@
+/* -*- 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/ChannelMergerNode.h"
+#include "mozilla/dom/ChannelMergerNodeBinding.h"
+#include "AudioNodeEngine.h"
+#include "AudioNodeTrack.h"
+#include "nsPrintfCString.h"
+#include "Tracing.h"
+
+namespace mozilla::dom {
+
+class ChannelMergerNodeEngine final : public AudioNodeEngine {
+ public:
+  explicit ChannelMergerNodeEngine(ChannelMergerNode* 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() == InputCount());
+    MOZ_ASSERT(aOutput.Length() == 1, "Should have only one output port");
+    TRACE("ChannelMergerNodeEngine::ProcessBlocksOnPorts");
+
+    // Get the number of output channels, and allocate it
+    size_t channelCount = InputCount();
+    bool allNull = true;
+    for (size_t i = 0; i < channelCount; ++i) {
+      allNull &= aInput[i].IsNull();
+    }
+    if (allNull) {
+      aOutput[0].SetNull(WEBAUDIO_BLOCK_SIZE);
+      return;
+    }
+
+    aOutput[0].AllocateChannels(channelCount);
+
+    for (size_t i = 0; i < channelCount; ++i) {
+      float* output = aOutput[0].ChannelFloatsForWrite(i);
+      if (aInput[i].IsNull()) {
+        PodZero(output, WEBAUDIO_BLOCK_SIZE);
+      } else {
+        AudioBlockCopyChannelWithScale(
+            static_cast<const float*>(aInput[i].mChannelData[0]),
+            aInput[i].mVolume, output);
+      }
+    }
+  }
+
+  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override {
+    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+  }
+};
+
+ChannelMergerNode::ChannelMergerNode(AudioContext* aContext,
+                                     uint16_t aInputCount)
+    : AudioNode(aContext, 1, ChannelCountMode::Explicit,
+                ChannelInterpretation::Speakers),
+      mInputCount(aInputCount) {
+  mTrack =
+      AudioNodeTrack::Create(aContext, new ChannelMergerNodeEngine(this),
+                             AudioNodeTrack::NO_TRACK_FLAGS, aContext->Graph());
+}
+
+/* static */
+already_AddRefed<ChannelMergerNode> ChannelMergerNode::Create(
+    AudioContext& aAudioContext, const ChannelMergerOptions& aOptions,
+    ErrorResult& aRv) {
+  if (aOptions.mNumberOfInputs == 0 ||
+      aOptions.mNumberOfInputs > WebAudioUtils::MaxChannelCount) {
+    aRv.ThrowIndexSizeError(
+        nsPrintfCString("Number of inputs (%u) must be in the range [1, number "
+                        "of supported channels]",
+                        aOptions.mNumberOfInputs));
+    return nullptr;
+  }
+
+  RefPtr<ChannelMergerNode> audioNode =
+      new ChannelMergerNode(&aAudioContext, aOptions.mNumberOfInputs);
+
+  audioNode->Initialize(aOptions, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  return audioNode.forget();
+}
+
+JSObject* ChannelMergerNode::WrapObject(JSContext* aCx,
+                                        JS::Handle<JSObject*> aGivenProto) {
+  return ChannelMergerNode_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+}  // namespace mozilla::dom