Quelle  ChannelSplitterNode.cpp   Sprache: C

/* -*- 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