media/audio/fake_audio_input_stream.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/audio/fake_audio_input_stream.h"
   6
   7 #include "base/bind.h"
   8 #include "media/audio/audio_manager_base.h"
   9
  10 using base::Time;
  11 using base::TimeDelta;
  12
  13 namespace media {
  14
  15 AudioInputStream* FakeAudioInputStream::MakeFakeStream(
  16     AudioManagerBase* manager,
  17     const AudioParameters& params) {
  18   return new FakeAudioInputStream(manager, params);
  19 }
  20
  21 FakeAudioInputStream::FakeAudioInputStream(AudioManagerBase* manager,
  22                                            const AudioParameters& params)
  23     : audio_manager_(manager),
  24       callback_(NULL),
  25       buffer_size_((params.channels() * params.bits_per_sample() *
  26                     params.frames_per_buffer()) / 8),
  27       thread_("FakeAudioRecordingThread"),
  28       callback_interval_(base::TimeDelta::FromMilliseconds(
  29           (params.frames_per_buffer() * 1000) / params.sample_rate())) {
  30 }
  31
  32 FakeAudioInputStream::~FakeAudioInputStream() {}
  33
  34 bool FakeAudioInputStream::Open() {
  35   buffer_.reset(new uint8[buffer_size_]);
  36   memset(buffer_.get(), 0, buffer_size_);
  37   return true;
  38 }
  39
  40 void FakeAudioInputStream::Start(AudioInputCallback* callback)  {
  41   DCHECK(!thread_.IsRunning());
  42   callback_ = callback;
  43   last_callback_time_ = Time::Now();
  44   thread_.Start();
  45   thread_.message_loop()->PostDelayedTask(
  46       FROM_HERE,
  47       base::Bind(&FakeAudioInputStream::DoCallback, base::Unretained(this)),
  48       callback_interval_);
  49 }
  50
  51 void FakeAudioInputStream::DoCallback() {
  52   DCHECK(callback_);
  53   callback_->OnData(this, buffer_.get(), buffer_size_, buffer_size_, 0.0);
  54
  55   Time now = Time::Now();
  56   base::TimeDelta next_callback_time =
  57       last_callback_time_ + callback_interval_ * 2 - now;
  58
  59   // If we are falling behind, try to catch up as much as we can in the next
  60   // callback.
  61   if (next_callback_time < base::TimeDelta())
  62     next_callback_time = base::TimeDelta();
  63
  64   last_callback_time_ = now;
  65   thread_.message_loop()->PostDelayedTask(
  66       FROM_HERE,
  67       base::Bind(&FakeAudioInputStream::DoCallback, base::Unretained(this)),
  68       next_callback_time);
  69 }
  70
  71 void FakeAudioInputStream::Stop() {
  72   thread_.Stop();
  73 }
  74
  75 void FakeAudioInputStream::Close() {
  76   if (callback_) {
  77     callback_->OnClose(this);
  78     callback_ = NULL;
  79   }
  80   audio_manager_->ReleaseInputStream(this);
  81 }
  82
  83 double FakeAudioInputStream::GetMaxVolume() {
  84   return 0.0;
  85 }
  86
  87 void FakeAudioInputStream::SetVolume(double volume) {}
  88
  89 double FakeAudioInputStream::GetVolume() {
  90   return 0.0;
  91 }
  92
  93 void FakeAudioInputStream::SetAutomaticGainControl(bool enabled) {}
  94
  95 bool FakeAudioInputStream::GetAutomaticGainControl() {
  96   return false;
  97 }
  98
  99 }  // namespace media