Adding input and output audio backend to Android.

media/audio/android/opensles_input.cc

+// Copyright (c) 2012 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.
+
+#include "media/audio/android/opensles_input.h"
+
+#include "base/logging.h"
+#include "media/audio/android/audio_manager_android.h"
+
+OpenSLESInputStream::OpenSLESInputStream(AudioManagerAndroid* audio_manager,
+                                         const AudioParameters& params)
+    : audio_manager_(audio_manager),
+      callback_(NULL),
+      recorder_(NULL),
+      simple_buffer_queue_(NULL),
+      active_queue_(0),
+      buffer_size_bytes_(0),
+      started_(false) {
+  format_.formatType = SL_DATAFORMAT_PCM;
+  format_.numChannels = static_cast<SLuint32>(params.channels());
+  // Provides sampling rate in milliHertz to OpenSLES.
+  format_.samplesPerSec = static_cast<SLuint32>(params.sample_rate() * 1000);
+  format_.bitsPerSample = params.bits_per_sample();
+  format_.containerSize = params.bits_per_sample();
+  format_.channelMask = SL_SPEAKER_FRONT_CENTER;
+  format_.endianness = SL_BYTEORDER_LITTLEENDIAN;
+
+  buffer_size_bytes_ = params.GetBytesPerBuffer();
+
+  for (int i = 0; i < kNumOfQueuesInBuffer; ++i) {

[qinmin, 2012/04/02 13:28:54]

I still prefer you put this into the Open() function. You can define a
ClearAudioData() function that gets called in both Close(), and the destructor
in case Close() is not getting called. Declaring sth and never using it  is
pretty common in actual practices.

[no longer working on chromium, 2012/04/02 15:17:38]

Done.

+    audio_data_[i] = new uint8[buffer_size_bytes_];
+  }
+}
+
+OpenSLESInputStream::~OpenSLESInputStream() {
+  DCHECK(!recorder_object_.Get());
+  DCHECK(!engine_object_.Get());
+  DCHECK(!recorder_);
+  DCHECK(!simple_buffer_queue_);
+  for (int i = 0; i < kNumOfQueuesInBuffer; ++i)
+    delete [] audio_data_[i];
+}
+
+bool OpenSLESInputStream::Open() {
+  if (engine_object_.Get())
+    return false;
+
+  return CreateRecorder();
+}
+
+void OpenSLESInputStream::Start(AudioInputCallback* callback) {
+  DCHECK(callback);
+  DCHECK(recorder_);
+  DCHECK(simple_buffer_queue_);
+  if (started_)
+    return;
+
+  // Enable the flags before streaming.
+  callback_ = callback;
+  active_queue_ = 0;
+  started_ = true;
+
+  SLresult err = SL_RESULT_UNKNOWN_ERROR;
+  // Enqueues |kNumOfQueuesInBuffer| zero buffers to get the ball rolling.
+  for (int i = 0; i < kNumOfQueuesInBuffer - 1; ++i) {
+    err = (*simple_buffer_queue_)->Enqueue(
+        simple_buffer_queue_,
+        audio_data_[i],
+        buffer_size_bytes_);
+    if (SL_RESULT_SUCCESS != err) {
+      HandleError(err);
+      return;
+    }
+  }
+
+  // Start the recording by setting the state to |SL_RECORDSTATE_RECORDING|.
+  err = (*recorder_)->SetRecordState(recorder_, SL_RECORDSTATE_RECORDING);
+  DCHECK_EQ(SL_RESULT_SUCCESS, err);
+  if (SL_RESULT_SUCCESS != err)
+    HandleError(err);
+}
+
+void OpenSLESInputStream::Stop() {
+  if (!started_)
+    return;
+
+  // Stop recording by setting the record state to |SL_RECORDSTATE_STOPPED|.
+  SLresult err = (*recorder_)->SetRecordState(recorder_,
+                                              SL_RECORDSTATE_STOPPED);
+  DLOG_IF(WARNING, SL_RESULT_SUCCESS != err) << "SetRecordState() failed to "
+                                             << "set the state to stop";
+
+  // Clear the buffer queue to get rid of old data when resuming recording.
+  err = (*simple_buffer_queue_)->Clear(simple_buffer_queue_);
+  DLOG_IF(WARNING, SL_RESULT_SUCCESS != err) << "Clear() failed to clear "
+                                             << "the buffer queue";
+
+  started_ = false;
+}
+
+void OpenSLESInputStream::Close() {
+  // Stop the stream if it is still recording.
+  Stop();
+
+  // Explicitly free the player objects and invalidate their associated
+  // interfaces. They have to be done in the correct order.
+  recorder_object_.Reset();
+  engine_object_.Reset();
+  simple_buffer_queue_ = NULL;
+  recorder_ = NULL;
+
+  audio_manager_->ReleaseInputStream(this);
+}
+
+double OpenSLESInputStream::GetMaxVolume() {
+  NOTIMPLEMENTED();
+  return 0.0;
+}
+
+void OpenSLESInputStream::SetVolume(double volume) {
+  NOTIMPLEMENTED();
+}
+
+double OpenSLESInputStream::GetVolume() {
+  NOTIMPLEMENTED();
+  return 0.0;
+}
+
+void OpenSLESInputStream::SetAutomaticGainControl(bool enabled) {
+  NOTIMPLEMENTED();
+}
+
+bool OpenSLESInputStream::GetAutomaticGainControl() {
+  NOTIMPLEMENTED();
+  return false;
+}
+
+bool OpenSLESInputStream::CreateRecorder() {
+  // Initializes the engine object with specific option. After working with the
+  // object, we need to free the object and its resources.
+  SLEngineOption option[] = {
+    { SL_ENGINEOPTION_THREADSAFE, static_cast<SLuint32>(SL_BOOLEAN_TRUE) }
+  };
+  SLresult err = slCreateEngine(engine_object_.Receive(),
+                                1,
+                                option,
+                                0,
+                                NULL,
+                                NULL);
+  DCHECK_EQ(SL_RESULT_SUCCESS, err);
+  if (SL_RESULT_SUCCESS != err)
+    return false;
+
+  // Realize the SL engine object in synchronous mode.
+  err = engine_object_->Realize(engine_object_.Get(), SL_BOOLEAN_FALSE);
+  DCHECK_EQ(SL_RESULT_SUCCESS, err);
+  if (SL_RESULT_SUCCESS != err)
+    return false;
+
+  // Get the SL engine interface which is implicit.
+  SLEngineItf engine;
+  err = engine_object_->GetInterface(
+      engine_object_.Get(), SL_IID_ENGINE, &engine);
+  DCHECK_EQ(SL_RESULT_SUCCESS, err);
+  if (SL_RESULT_SUCCESS != err)
+    return false;
+
+  // Audio source configuration.
+  SLDataLocator_IODevice mic_locator = {
+    SL_DATALOCATOR_IODEVICE, SL_IODEVICE_AUDIOINPUT,
+    SL_DEFAULTDEVICEID_AUDIOINPUT, NULL
+  };
+  SLDataSource audio_source = { &mic_locator, NULL };
+
+  // Audio sink configuration.
+  SLDataLocator_AndroidSimpleBufferQueue buffer_queue = {
+    SL_DATALOCATOR_ANDROIDSIMPLEBUFFERQUEUE, // Locator type.
+    static_cast<SLuint32>(kNumOfQueuesInBuffer)  // Number of buffers.
+  };
+  SLDataSink audio_sink = { &buffer_queue, &format_ };
+
+  // Create an audio recorder.
+  const SLuint32 number_of_interfaces = 1;
+  const SLInterfaceID interface_id[number_of_interfaces] = {
+    SL_IID_ANDROIDSIMPLEBUFFERQUEUE
+  };
+  const SLboolean interface_required[number_of_interfaces] = {
+    SL_BOOLEAN_TRUE
+  };
+  err = (*engine)->CreateAudioRecorder(engine,
+                                       recorder_object_.Receive(),
+                                       &audio_source,
+                                       &audio_sink,
+                                       number_of_interfaces,
+                                       interface_id,
+                                       interface_required);
+  DCHECK_EQ(SL_RESULT_SUCCESS, err);
+  if (SL_RESULT_SUCCESS != err) {
+    DLOG(ERROR) << "CreateAudioRecorder failed with error code " << err;
+    return false;
+  }
+
+  // Realize the recorder object in synchronous mode.
+  err = recorder_object_->Realize(recorder_object_.Get(), SL_BOOLEAN_FALSE);
+  DCHECK_EQ(SL_RESULT_SUCCESS, err);
+  if (SL_RESULT_SUCCESS != err) {
+    DLOG(ERROR) << "Recprder Realize() failed with error code " << err;
+    return false;
+  }
+
+  // Get an implicit recorder interface.
+  err = recorder_object_->GetInterface(recorder_object_.Get(),
+                                       SL_IID_RECORD,
+                                       &recorder_);
+  DCHECK_EQ(SL_RESULT_SUCCESS, err);
+  if (SL_RESULT_SUCCESS != err)
+    return false;
+
+  // Get the simple buffer queue interface.
+  err = recorder_object_->GetInterface(recorder_object_.Get(),
+                                       SL_IID_ANDROIDSIMPLEBUFFERQUEUE,
+                                       &simple_buffer_queue_);
+  DCHECK_EQ(SL_RESULT_SUCCESS, err);
+  if (SL_RESULT_SUCCESS != err)
+    return false;
+
+  // Register the input callback for the simple buffer queue.
+  // This callback will be called when receiving new data from the device.
+  err = (*simple_buffer_queue_)->RegisterCallback(simple_buffer_queue_,
+                                                  SimpleBufferQueueCallback,
+                                                  this);
+  DCHECK_EQ(SL_RESULT_SUCCESS, err);
+
+  return (SL_RESULT_SUCCESS == err);
+}
+
+void OpenSLESInputStream::SimpleBufferQueueCallback(
+    SLAndroidSimpleBufferQueueItf buffer_queue, void* instance) {
+  OpenSLESInputStream* stream =
+      reinterpret_cast<OpenSLESInputStream*>(instance);
+  stream->ReadBufferQueue();
+}
+
+void OpenSLESInputStream::ReadBufferQueue() {
+  if (!started_)
+    return;
+
+  // Get the enqueued buffer from the soundcard.
+  SLresult err = (*simple_buffer_queue_)->Enqueue(
+      simple_buffer_queue_,
+      audio_data_[active_queue_],
+      buffer_size_bytes_);
+  if (SL_RESULT_SUCCESS != err)
+    HandleError(err);
+
+  // TODO(xians): Get an accurate delay estimation.
+  callback_->OnData(this,
+                    audio_data_[active_queue_],
+                    buffer_size_bytes_,
+                    buffer_size_bytes_,
+                    0.0);
+
+  active_queue_ = ++active_queue_ % kNumOfQueuesInBuffer;
+}
+
+void OpenSLESInputStream::HandleError(SLresult error) {
+  DLOG(FATAL) << "OpenSLES error " << error;
+  if (callback_)
+    callback_->OnError(this, error);
+}