Implementation of ppapi audio.

content/renderer/pepper_plugin_delegate_impl.cc

Index: content/renderer/pepper_plugin_delegate_impl.cc
===================================================================
--- content/renderer/pepper_plugin_delegate_impl.cc	(revision 103964)
+++ content/renderer/pepper_plugin_delegate_impl.cc	(working copy)
@@ -35,6 +35,7 @@
 #include "content/renderer/gpu/renderer_gl_context.h"
 #include "content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h"
 #include "content/renderer/media/audio_message_filter.h"
+#include "content/renderer/media/audio_input_message_filter.h"
 #include "content/renderer/media/video_capture_impl_manager.h"
 #include "content/renderer/p2p/p2p_transport_impl.h"
 #include "content/renderer/pepper_platform_context_3d_impl.h"
@@ -335,6 +336,179 @@
   }
 }
 
+class PlatformAudioInputImpl
+    : public webkit::ppapi::PluginDelegate::PlatformAudioInput,
+      public AudioInputMessageFilter::Delegate,
+      public base::RefCountedThreadSafe<PlatformAudioInputImpl> {
+ public:
+  PlatformAudioInputImpl()
+      : client_(NULL), stream_id_(0),
+        main_message_loop_(MessageLoop::current()) {
+    filter_ = RenderThread::current()->audio_input_message_filter();
+  }
+
+  virtual ~PlatformAudioInputImpl() {
+    // Make sure we have been shut down. Warning: this will usually happen on
+    // the I/O thread!
+    DCHECK_EQ(0, stream_id_);
+    DCHECK(!client_);
+  }
+
+  // Initialize this audio context. StreamCreated() will be called when the
+  // stream is created.
+  bool Initialize(
+          webkit::ppapi::PluginDelegate::PlatformAudioInput::Client* client);

[brettw, 2011/10/12 19:33:13]

Should be indented only 4 spaces

+
+  // PlatformAudio implementation (called on main thread).
+  virtual bool StartCapture();
+  virtual bool StopCapture();
+  virtual void ShutDown();
+
+ private:
+  // I/O thread backends to above functions.
+  void InitializeOnIOThread(const AudioParameters& params);
+  void StartCaptureOnIOThread();
+  void StopCaptureOnIOThread();
+  void ShutDownOnIOThread();
+
+  virtual void OnLowLatencyCreated(base::SharedMemoryHandle handle,
+                                   base::SyncSocket::Handle socket_handle,
+                                   uint32 length);
+
+  virtual void OnVolume(double volume) {}
+
+  virtual void OnStateChanged(AudioStreamState state) {}
+
+  //TODO(peterb) need to add

[brettw, 2011/10/12 20:39:34]

This should be cleaned up or clarified.

+  virtual void OnDeviceReady(int index) {};
+
+  // The client to notify when the stream is created. THIS MUST ONLY BE
+  // ACCESSED ON THE MAIN THREAD.
+  webkit::ppapi::PluginDelegate::PlatformAudioInput::Client* client_;
+
+  // 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.
+  scoped_refptr<AudioInputMessageFilter> filter_;
+
+  // Our ID on the MessageFilter. 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_;
+
+  MessageLoop* main_message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(PlatformAudioInputImpl);
+};
+
+bool PlatformAudioInputImpl::Initialize(
+    webkit::ppapi::PluginDelegate::PlatformAudioInput::Client* client) {
+  DCHECK(client);
+  // Make sure we don't call init more than once.
+  DCHECK_EQ(0, stream_id_);
+
+  client_ = client;
+
+//TODO(peterb) figure out the params to use

[brettw, 2011/10/12 20:39:34]

Did you figure out the proper params? Can this be finalized now and your
comments deleted?

+  AudioParameters params;
+  params.format = AudioParameters::AUDIO_PCM_LINEAR;
+  params.channels = 2;
+//peterb  params.sample_rate = sample_rate;
+  params.sample_rate = 44100; //peterb PP_AUDIOSAMPLERATE_44100;
+  params.bits_per_sample = 16;
+//peterb  params.samples_per_packet = sample_count;
+  params.samples_per_packet = 2048;
+
+  ChildProcess::current()->io_message_loop()->PostTask(
+      FROM_HERE,
+      NewRunnableMethod(this, &PlatformAudioInputImpl::InitializeOnIOThread,
+                        params));
+  return true;
+}
+
+bool PlatformAudioInputImpl::StartCapture() {
+  if (filter_) {

[brettw, 2011/10/12 20:39:34]

I don't think this can be NULL. I notice the existing output API checks for NULL
in some cases and doesn't in others. I wonder if the checking code is either
wrong or obsolete. Unless you know of a reason why this can be NULL, let's
remove the checks and assume it's always non-NULL.

+    ChildProcess::current()->io_message_loop()->PostTask(
+        FROM_HERE,
+        NewRunnableMethod(this,
+                          &PlatformAudioInputImpl::StartCaptureOnIOThread));
+    return true;
+  }
+  return false;
+}
+
+bool PlatformAudioInputImpl::StopCapture() {
+  if (filter_) {
+    ChildProcess::current()->io_message_loop()->PostTask(
+        FROM_HERE,
+        NewRunnableMethod(this,
+                          &PlatformAudioInputImpl::StopCaptureOnIOThread));
+    return true;
+  }
+  return false;
+}
+
+void PlatformAudioInputImpl::ShutDown() {
+  // Called on the main thread to stop all audio callbacks. We must only change
+  // the client on the main thread, and the delegates from the I/O thread.
+  client_ = NULL;
+  ChildProcess::current()->io_message_loop()->PostTask(
+      FROM_HERE,
+      NewRunnableMethod(this, &PlatformAudioInputImpl::ShutDownOnIOThread));
+}
+
+void PlatformAudioInputImpl::InitializeOnIOThread(
+                                       const AudioParameters& params) {

[brettw, 2011/10/12 19:33:13]

Only 4 space indent.

+  stream_id_ = filter_->AddDelegate(this);
+  filter_->Send(new AudioInputHostMsg_CreateStream(stream_id_, params, true));
+}
+
+void PlatformAudioInputImpl::StartCaptureOnIOThread() {
+  if (stream_id_)
+    filter_->Send(new AudioInputHostMsg_RecordStream(stream_id_));
+}
+
+void PlatformAudioInputImpl::StopCaptureOnIOThread() {
+  if (stream_id_)
+    filter_->Send(new AudioInputHostMsg_CloseStream(stream_id_));
+}
+
+void PlatformAudioInputImpl::ShutDownOnIOThread() {
+  // Make sure we don't call shutdown more than once.
+  if (!stream_id_)
+    return;
+
+  filter_->Send(new AudioInputHostMsg_CloseStream(stream_id_));
+  filter_->RemoveDelegate(stream_id_);
+  stream_id_ = 0;
+
+  Release();  // Release for the delegate, balances out the reference taken in
+              // PepperPluginDelegateImpl::CreateAudioInput.
+}
+
+void PlatformAudioInputImpl::OnLowLatencyCreated(
+    base::SharedMemoryHandle handle, base::SyncSocket::Handle socket_handle,

[brettw, 2011/10/12 20:39:34]

Style nit: I usually try to put each param on a separate line when I'm using
multiple lines like this, so maybe put socket_handle on its own line?

+    uint32 length) {
+
+#if defined(OS_WIN)
+  DCHECK(handle);
+  DCHECK(socket_handle);
+#else
+  DCHECK_NE(-1, handle.fd);
+  DCHECK_NE(-1, socket_handle);
+#endif
+  DCHECK(length);
+
+  if (MessageLoop::current() == main_message_loop_) {
+    // Must dereference the client only on the main thread. Shutdown may have
+    // occurred while the request was in-flight, so we need to NULL check.
+    if (client_)
+      client_->StreamCreated(handle, length, socket_handle);
+  } else {
+    main_message_loop_->PostTask(FROM_HERE,
+        NewRunnableMethod(this, &PlatformAudioInputImpl::OnLowLatencyCreated,
+                          handle, socket_handle, length));
+  }
+}
+
 class DispatcherDelegate : public ppapi::proxy::ProxyChannel::Delegate {
  public:
   virtual ~DispatcherDelegate() {}
@@ -986,6 +1160,22 @@
   }
 }
 
+webkit::ppapi::PluginDelegate::PlatformAudioInput*
+PepperPluginDelegateImpl::CreateAudioInput(
+    webkit::ppapi::PluginDelegate::PlatformAudioInput::Client* client) {
+  scoped_refptr<PlatformAudioInputImpl>
+                             audio_input(new PlatformAudioInputImpl());

[brettw, 2011/10/12 19:33:13]

4 space indent.

+  if (audio_input->Initialize(client)) {
+    // Balanced by Release invoked in
+    // PlatformAudioInputImpl::ShutDownOnIOThread().
+    return audio_input.release();
+  } else {

[brettw, 2011/10/12 20:39:34]

I'd just delete this else condition and use the return NULL at the outer scope.

+    return NULL;
+  }
+  return NULL;
+}
+
+
 // If a broker has not already been created for this plugin, creates one.
 webkit::ppapi::PluginDelegate::PpapiBroker*
 PepperPluginDelegateImpl::ConnectToPpapiBroker(