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/*
* 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.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE 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 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_PLATFORM_AUDIO_AUDIO_DESTINATION_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_DESTINATION_H_
#include <memory>
#include "base/memory/scoped_refptr.h"
#include "base/single_thread_task_runner.h"
#include "third_party/blink/public/platform/web_audio_device.h"
#include "third_party/blink/public/platform/web_thread.h"
#include "third_party/blink/public/platform/web_vector.h"
#include "third_party/blink/renderer/platform/audio/audio_bus.h"
#include "third_party/blink/renderer/platform/audio/audio_io_callback.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
#include "third_party/blink/renderer/platform/wtf/thread_safe_ref_counted.h"
namespace blink {
class PushPullFIFO;
class WebAudioLatencyHint;
// The AudioDestination class is an audio sink interface between the media
// renderer and the Blink's WebAudio module. It has a FIFO to adapt the
// different processing block sizes of WebAudio renderer and actual hardware
// audio callback.
//
// Currently AudioDestination supports two types of threading models:
// - Single-thread (default): process the entire WebAudio render call chain by
// AudioDeviceThread.
// - Dual-thread (experimental): Use WebThread for the WebAudio rendering with
// AudioWorkletThread.
class PLATFORM_EXPORT AudioDestination
: public ThreadSafeRefCounted<AudioDestination>,
public WebAudioDevice::RenderCallback {
USING_FAST_MALLOC(AudioDestination);
WTF_MAKE_NONCOPYABLE(AudioDestination);
public:
AudioDestination(AudioIOCallback&,
unsigned number_of_output_channels,
const WebAudioLatencyHint&);
~AudioDestination() override;
static scoped_refptr<AudioDestination> Create(
AudioIOCallback&,
unsigned number_of_output_channels,
const WebAudioLatencyHint&);
// The actual render function (WebAudioDevice::RenderCallback) isochronously
// invoked by the media renderer. This is never called after Stop() is called.
void Render(const WebVector<float*>& destination_data,
size_t number_of_frames,
double delay,
double delay_timestamp,
size_t prior_frames_skipped) override;
// The actual render request to the WebAudio destination node. This method
// can be invoked on both AudioDeviceThread (single-thread rendering) and
// AudioWorkletThread (dual-thread rendering).
void RequestRender(size_t frames_requested,
size_t frames_to_render,
double delay,
double delay_timestamp,
size_t prior_frames_skipped);
virtual void Start();
virtual void Stop();
// Starts the destination with the AudioWorklet support.
void StartWithWorkletTaskRunner(
scoped_refptr<base::SingleThreadTaskRunner> worklet_task_runner);
// Getters must be accessed from the main thread.
size_t CallbackBufferSize() const;
bool IsPlaying();
// TODO(hongchan): this should not be called by the rendering thread.
double SampleRate() const { return web_audio_device_->SampleRate(); }
// Returns the audio buffer size in frames used by the underlying audio
// hardware.
int FramesPerBuffer() const;
// The information from the actual audio hardware. (via Platform::current)
static float HardwareSampleRate();
static unsigned long MaxChannelCount();
private:
// Check if the buffer size chosen by the WebAudioDevice is too large.
bool CheckBufferSize();
size_t HardwareBufferSize();
// Accessed by the main thread.
std::unique_ptr<WebAudioDevice> web_audio_device_;
const unsigned number_of_output_channels_;
size_t callback_buffer_size_;
bool is_playing_;
// The task runner for AudioWorklet operation. This is only valid when
// the AudioWorklet is activated.
scoped_refptr<base::SingleThreadTaskRunner> worklet_task_runner_;
// Can be accessed by both threads: resolves the buffer size mismatch between
// the WebAudio engine and the callback function from the actual audio device.
std::unique_ptr<PushPullFIFO> fifo_;
// Accessed by device thread: to pass the data from FIFO to the device.
scoped_refptr<AudioBus> output_bus_;
// Accessed by rendering thread: to push the rendered result from WebAudio
// graph into the FIFO.
scoped_refptr<AudioBus> render_bus_;
// Keeps track if the output of this destination was audible, before the
// current rendering quantum. Used for recording "playback" time.
bool was_audible_ = false;
// Counts the number of render quanta where audible sound was played. We
// determine audibility on render quantum boundaries, so counting quanta is
// all that's needed.
size_t total_audible_renders_ = 0;
// Accessed by rendering thread: the render callback function of WebAudio
// engine. (i.e. DestinationNode)
AudioIOCallback& callback_;
// Accessed by rendering thread.
size_t frames_elapsed_;
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_DESTINATION_H_
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