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// Copyright (c) 2011 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_AUDIO_INPUT_DEVICE_H_
#define CONTENT_RENDERER_AUDIO_INPUT_DEVICE_H_
#pragma once
#include <vector>
#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
#include "base/shared_memory.h"
#include "base/threading/simple_thread.h"
#include "content/renderer/audio_input_message_filter.h"
struct AudioParameters;
// Each instance of AudioInputDevice corresponds to one host stream.
// This class is not thread-safe, so its methods must be called from
// the same thread.
// TODO(henrika): This class is based on the AudioDevice class and it has
// many components in common. Investigate potential for re-factoring.
class AudioInputDevice : public AudioInputMessageFilter::Delegate,
public base::DelegateSimpleThread::Delegate,
public base::RefCountedThreadSafe<AudioInputDevice> {
public:
class CaptureCallback {
public:
virtual void Capture(const std::vector<float*>& audio_data,
size_t number_of_frames,
size_t audio_delay_milliseconds) = 0;
protected:
virtual ~CaptureCallback() {}
};
// |buffer_size| is the number of sample-frames.
AudioInputDevice(size_t buffer_size,
int channels,
double sample_rate,
CaptureCallback* callback);
virtual ~AudioInputDevice();
// Starts audio capturing. Returns |true| on success.
bool Start();
// Stops audio capturing. Returns |true| on success.
bool Stop();
// Sets the capture volume scaling, with range [0.0, 1.0] inclusive.
// Returns |true| on success.
bool SetVolume(double volume);
// Gets the capture volume scaling, with range [0.0, 1.0] inclusive.
// Returns |true| on success.
bool GetVolume(double* volume);
double sample_rate() const { return sample_rate_; }
size_t buffer_size() const { return buffer_size_; }
private:
// I/O thread backends to above functions.
void InitializeOnIOThread(const AudioParameters& params);
void StartOnIOThread();
void ShutDownOnIOThread();
void SetVolumeOnIOThread(double volume);
// AudioInputMessageFilter::Delegate implementation
virtual void OnLowLatencyCreated(base::SharedMemoryHandle handle,
base::SyncSocket::Handle socket_handle,
uint32 length);
virtual void OnVolume(double volume);
// DelegateSimpleThread::Delegate implementation.
virtual void Run();
// Format
size_t buffer_size_; // in sample-frames
int channels_;
int bits_per_sample_;
double sample_rate_;
// Calls the client's callback for capturing audio.
void FireCaptureCallback();
CaptureCallback* callback_;
// The client callback receives captured audio here.
std::vector<float*> audio_data_;
// The client stores the last reported audio delay in this member.
// The delay shall reflect the amount of audio which still resides in
// the input buffer, i.e., the expected audio input delay.
int audio_delay_milliseconds_;
// The current volume scaling [0.0, 1.0] of the audio stream.
double volume_;
// Callbacks for capturing audio occur on this thread.
scoped_ptr<base::DelegateSimpleThread> audio_thread_;
// IPC message stuff.
base::SharedMemory* shared_memory() { return shared_memory_.get(); }
base::SyncSocket* socket() { return socket_.get(); }
void* shared_memory_data() { return shared_memory()->memory(); }
// MessageFilter used to send/receive IPC. THIS MUST ONLY BE ACCESSED ON THE
// I/O thread except to send messages and get the message loop.
static scoped_refptr<AudioInputMessageFilter> filter_;
// Our ID on the message filter. THIS MUST ONLY BE ACCESSED ON THE I/O THREAD
// or else you could race with the initialize function which sets it.
int32 stream_id_;
scoped_ptr<base::SharedMemory> shared_memory_;
scoped_ptr<base::SyncSocket> socket_;
DISALLOW_IMPLICIT_CONSTRUCTORS(AudioInputDevice);
};
#endif // CONTENT_RENDERER_AUDIO_INPUT_DEVICE_H_
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