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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_RENDERER_PEPPER_PEPPER_MEDIA_STREAM_AUDIO_TRACK_HOST_H_
#define CONTENT_RENDERER_PEPPER_PEPPER_MEDIA_STREAM_AUDIO_TRACK_HOST_H_
#include <stdint.h>
#include <memory>
#include "base/compiler_specific.h"
#include "base/containers/circular_deque.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/synchronization/lock.h"
#include "base/threading/thread_checker.h"
#include "content/public/renderer/media_stream_audio_sink.h"
#include "content/renderer/pepper/pepper_media_stream_track_host_base.h"
#include "media/base/audio_parameters.h"
#include "ppapi/host/host_message_context.h"
#include "ppapi/shared_impl/media_stream_audio_track_shared.h"
#include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
namespace base {
class SingleThreadTaskRunner;
} // namespace base
namespace content {
class PepperMediaStreamAudioTrackHost : public PepperMediaStreamTrackHostBase {
public:
PepperMediaStreamAudioTrackHost(RendererPpapiHost* host,
PP_Instance instance,
PP_Resource resource,
const blink::WebMediaStreamTrack& track);
private:
// A helper class for receiving audio samples in the audio thread.
// This class is created and destroyed on the renderer main thread.
class AudioSink : public MediaStreamAudioSink {
public:
explicit AudioSink(PepperMediaStreamAudioTrackHost* host);
~AudioSink() override;
// Enqueues a free buffer index into |buffers_| which will be used for
// sending audio samples to plugin.
// This function is called on the main thread.
void EnqueueBuffer(int32_t index);
// This function is called on the main thread.
int32_t Configure(int32_t number_of_buffers, int32_t duration,
const ppapi::host::ReplyMessageContext& context);
// Send a reply to the currently pending |Configure()| request.
void SendConfigureReply(int32_t result);
// MediaStreamAudioSink overrides:
// These two functions should be called on the audio thread.
// NOTE: For this specific instance, |OnSetFormat()| is also called on the
// main thread. However, the call to |OnSetFormat()| happens before this
// sink is added to an audio track, also on the main thread, which should
// avoid any potential races.
void OnData(const media::AudioBus& audio_bus,
base::TimeTicks estimated_capture_time) override;
void OnSetFormat(const media::AudioParameters& params) override;
private:
// Initializes buffers on the main thread.
void SetFormatOnMainThread(int bytes_per_second, int bytes_per_frame);
void InitBuffers();
// Send enqueue buffer message on the main thread.
void SendEnqueueBufferMessageOnMainThread(int32_t index,
int32_t buffers_generation);
// Unowned host which is available during the AudioSink's lifespan.
// It is mainly used in the main thread. But the audio thread will use
// host_->buffer_manager() to read some buffer properties. It is safe
// because the buffer_manager()'s properties will not be changed after
// initialization.
PepperMediaStreamAudioTrackHost* host_;
// The estimated capture time of the first sample frame of audio. This is
// used as the timebase to compute the buffer timestamps.
// Access only on the audio thread.
base::TimeTicks first_frame_capture_time_;
// The current audio parameters.
// Access only on the audio thread.
media::AudioParameters audio_params_;
// Index of the currently active buffer.
// Access only on the audio thread.
int active_buffer_index_;
// Generation of buffers corresponding to the currently active
// buffer. Used to make sure the active buffer is still valid.
// Access only on the audio thread.
int32_t active_buffers_generation_;
// Current offset, in sample frames, within the currently active buffer.
// Access only on the audio thread.
int active_buffer_frame_offset_;
// A lock to protect the index queue |buffers_|, |buffers_generation_|,
// buffers in |host_->buffer_manager()|, and |output_buffer_size_|.
base::Lock lock_;
// A queue for free buffer indices.
base::circular_deque<int32_t> buffers_;
// Generation of buffers. It is increased by every |InitBuffers()| call.
int32_t buffers_generation_;
// Intended size of each output buffer.
int32_t output_buffer_size_;
scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
base::ThreadChecker audio_thread_checker_;
// Number of buffers.
int32_t number_of_buffers_;
// Number of bytes per second.
int bytes_per_second_;
// Number of bytes per frame = channels * bytes per sample.
int bytes_per_frame_;
// User-configured buffer duration, in milliseconds.
int32_t user_buffer_duration_;
// Pending |Configure()| reply context.
ppapi::host::ReplyMessageContext pending_configure_reply_;
base::WeakPtrFactory<AudioSink> weak_factory_;
DISALLOW_COPY_AND_ASSIGN(AudioSink);
};
~PepperMediaStreamAudioTrackHost() override;
// ResourceMessageHandler overrides:
int32_t OnResourceMessageReceived(
const IPC::Message& msg,
ppapi::host::HostMessageContext* context) override;
// Message handlers:
int32_t OnHostMsgConfigure(
ppapi::host::HostMessageContext* context,
const ppapi::MediaStreamAudioTrackShared::Attributes& attributes);
// PepperMediaStreamTrackHostBase overrides:
void OnClose() override;
// MediaStreamBufferManager::Delegate overrides:
void OnNewBufferEnqueued() override;
// ResourceHost overrides:
void DidConnectPendingHostToResource() override;
blink::WebMediaStreamTrack track_;
// True if |audio_sink_| has been added to |blink::WebMediaStreamTrack|
// as a sink.
bool connected_;
AudioSink audio_sink_;
DISALLOW_COPY_AND_ASSIGN(PepperMediaStreamAudioTrackHost);
};
} // namespace content
#endif // CONTENT_RENDERER_PEPPER_PEPPER_MEDIA_STREAM_AUDIO_TRACK_HOST_H_
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