Refactor content::RenderAudioSourceProvider as webkit_media::WebAudioSourceProviderImpl.

webkit/media/webaudiosourceprovider_impl.cc

+// Copyright (c) 2013 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 "webkit/media/webaudiosourceprovider_impl.h"
+
+#include <vector>
+
+#include "base/logging.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebAudioSourceProviderClient.h"
+
+using WebKit::WebVector;
+
+namespace webkit_media {
+
+WebAudioSourceProviderImpl::WebAudioSourceProviderImpl(
+    const scoped_refptr<media::AudioRendererSink>& sink)
+    : is_initialized_(false),
+      channels_(0),
+      sample_rate_(0),
+      is_running_(false),
+      renderer_(NULL),
+      client_(NULL),
+      sink_(sink) {
+}
+
+WebAudioSourceProviderImpl::~WebAudioSourceProviderImpl() {}
+
+void WebAudioSourceProviderImpl::setClient(
+    WebKit::WebAudioSourceProviderClient* client) {
+  base::AutoLock auto_lock(sink_lock_);
+
+  if (client && client != client_) {
+    // Detach the audio renderer from normal playback.
+    sink_->Stop();
+
+    // The client will now take control by calling provideInput() periodically.
+    client_ = client;
+
+    if (is_initialized_) {
+      // The client needs to be notified of the audio format, if available.
+      // If the format is not yet available, we'll be notified later
+      // when Initialize() is called.
+
+      // Inform WebKit about the audio stream format.
+      client->setFormat(channels_, sample_rate_);
+    }
+  } else if (!client && client_) {
+    // Restore normal playback.
+    client_ = NULL;
+    // TODO(crogers): We should call sink_->Play() if we're
+    // in the playing state.
+  }
+}
+
+void WebAudioSourceProviderImpl::provideInput(
+    const WebVector<float*>& audio_data, size_t number_of_frames) {
+  DCHECK(client_);
+
+  if (renderer_ && is_initialized_ && is_running_) {
+    // Wrap WebVector as std::vector.
+    std::vector<float*> v(audio_data.size());
+    for (size_t i = 0; i < audio_data.size(); ++i)
+      v[i] = audio_data[i];
+
+    scoped_ptr<media::AudioBus> audio_bus = media::AudioBus::WrapVector(
+        number_of_frames, v);
+
+    // TODO(crogers): figure out if we should volume scale here or in common
+    // WebAudio code.  In any case we need to take care of volume.
+    renderer_->Render(audio_bus.get(), 0);
+    return;
+  }
+
+  // Provide silence if the source is not running.
+  for (size_t i = 0; i < audio_data.size(); ++i)
+    memset(audio_data[i], 0, sizeof(*audio_data[0]) * number_of_frames);
+}
+
+void WebAudioSourceProviderImpl::Start() {
+  base::AutoLock auto_lock(sink_lock_);
+  if (!client_)
+    sink_->Start();
+  is_running_ = true;

[miu, 2013/01/09 18:48:35]

Weirdness in existing code (not part of your change, but...): Perhaps you should
remove this statement here, since calling sink_->Start() doesn't mean the sink
is consuming audio yet.

[scherkus (not reviewing), 2013/01/09 23:16:06]

Discussed offline, ARS::Start() does indeed start playback! Play() is for after
calling Pause()

+}
+
+void WebAudioSourceProviderImpl::Stop() {
+  base::AutoLock auto_lock(sink_lock_);
+  if (!client_)
+    sink_->Stop();
+  is_running_ = false;
+}
+
+void WebAudioSourceProviderImpl::Play() {
+  base::AutoLock auto_lock(sink_lock_);
+  if (!client_)
+    sink_->Play();
+  is_running_ = true;
+}
+
+void WebAudioSourceProviderImpl::Pause(bool flush) {
+  base::AutoLock auto_lock(sink_lock_);
+  if (!client_)
+    sink_->Pause(flush);
+  is_running_ = false;
+}
+
+bool WebAudioSourceProviderImpl::SetVolume(double volume) {
+  base::AutoLock auto_lock(sink_lock_);
+  if (!client_)
+    sink_->SetVolume(volume);
+  return true;
+}
+
+void WebAudioSourceProviderImpl::Initialize(
+    const media::AudioParameters& params,
+    RenderCallback* renderer) {
+  base::AutoLock auto_lock(sink_lock_);
+  CHECK(!is_initialized_);
+  renderer_ = renderer;
+
+  sink_->Initialize(params, renderer);
+
+  // Keep track of the format in case the client hasn't yet been set.
+  channels_ = params.channels();
+  sample_rate_ = params.sample_rate();
+
+  if (client_) {
+    // Inform WebKit about the audio stream format.
+    client_->setFormat(channels_, sample_rate_);
+  }
+
+  is_initialized_ = true;
+}
+
+}  // namespace webkit_media