| /* |
| * Copyright (C) 2010, Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH |
| * DAMAGE. |
| */ |
| |
| #ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_AUDIO_DESTINATION_NODE_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_AUDIO_DESTINATION_NODE_H_ |
| |
| #include <atomic> |
| #include "third_party/blink/renderer/modules/webaudio/audio_node.h" |
| |
| namespace blink { |
| |
| // The AudioDestinationHandler (ADH) is a base class for the rendering backend |
| // for AudioDestinatioNode. It contains common information required for the |
| // rendering such as current sample frame, sample rate and maximum channel count |
| // of the context. |
| class AudioDestinationHandler : public AudioHandler { |
| public: |
| AudioDestinationHandler(AudioNode&); |
| ~AudioDestinationHandler() override; |
| |
| // The method MUST NOT be invoked when rendering a graph because the |
| // destination node is a sink. Instead, this node gets pulled by the |
| // underlying renderer (audio hardware or worker thread). |
| void Process(uint32_t) final { NOTREACHED(); } |
| |
| virtual void StartRendering() = 0; |
| virtual void StopRendering() = 0; |
| virtual void Pause() = 0; |
| virtual void Resume() = 0; |
| |
| // The render thread needs to be changed after Worklet JS code is loaded by |
| // AudioWorklet. This method ensures the switching of render thread and the |
| // restart of the context. |
| virtual void RestartRendering() = 0; |
| |
| size_t CurrentSampleFrame() const { |
| return current_sample_frame_.load(std::memory_order_acquire); |
| } |
| |
| double CurrentTime() const { |
| return CurrentSampleFrame() / SampleRate(); |
| } |
| |
| virtual double SampleRate() const = 0; |
| virtual uint32_t MaxChannelCount() const = 0; |
| |
| void ContextDestroyed() { is_execution_context_destroyed_ = true; } |
| bool IsExecutionContextDestroyed() const { |
| return is_execution_context_destroyed_; |
| } |
| |
| protected: |
| void AdvanceCurrentSampleFrame(size_t number_of_frames) { |
| current_sample_frame_.fetch_add(number_of_frames, |
| std::memory_order_release); |
| } |
| |
| private: |
| // The number of sample frames processed by the destination so far. |
| std::atomic_size_t current_sample_frame_{0}; |
| |
| // True if the execution context is being destroyed. If this is true, the |
| // destination ndoe must avoid checking for or accessing the execution |
| // context. |
| bool is_execution_context_destroyed_ = false; |
| }; |
| |
| // ----------------------------------------------------------------------------- |
| |
| // AudioDestinationNode (ADN) is a base class of two different types of nodes: |
| // 1. DefaultDestinationNode for AudioContext (real time) |
| // 2. OfflineDestinationNode for OfflineAudioContext (non-real time) |
| // They have different rendering mechanisms, so the AudioDestinationHandler |
| // (ADH), which is a counterpart of the destination node, encapsulates a |
| // different rendering backend. |
| class AudioDestinationNode : public AudioNode { |
| DEFINE_WRAPPERTYPEINFO(); |
| |
| public: |
| uint32_t maxChannelCount() const; |
| |
| // Returns its own handler object instead of a generic one from |
| // AudioNode::Handler(). |
| AudioDestinationHandler& GetAudioDestinationHandler() const; |
| |
| protected: |
| AudioDestinationNode(BaseAudioContext&); |
| }; |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_AUDIO_DESTINATION_NODE_H_ |