Cast: Basic cast_receiver API for chrome.

chrome/renderer/media/cast_receiver_session_delegate.cc

+// Copyright 2015 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 "chrome/renderer/media/cast_receiver_session_delegate.h"
+
+#include "base/synchronization/waitable_event.h"
+#include "base/values.h"
+
+CastReceiverSessionDelegate::CastReceiverSessionDelegate()
+    : weak_factory_(this) {
+}
+CastReceiverSessionDelegate::~CastReceiverSessionDelegate() {}
+
+void CastReceiverSessionDelegate::LogRawEvents(
+    const std::vector<media::cast::PacketEvent>& packet_events,
+    const std::vector<media::cast::FrameEvent>& frame_events) {
+  NOTREACHED();
+}
+
+void CastReceiverSessionDelegate::Start(
+    const media::cast::FrameReceiverConfig& audio_config,
+    const media::cast::FrameReceiverConfig& video_config,
+    const net::IPEndPoint& local_endpoint,
+    const net::IPEndPoint& remote_endpoint,
+    scoped_ptr<base::DictionaryValue> options,
+    const media::VideoCaptureFormat& format) {
+  format_ = format;
+  DCHECK(io_message_loop_proxy_->BelongsToCurrentThread());
+  CastSessionDelegateBase::StartUDP(local_endpoint,
+                                    remote_endpoint,
+                                    options.Pass());
+  cast_receiver_ = media::cast::CastReceiver::Create(cast_environment_,
+                                                     audio_config,
+                                                     video_config,
+                                                     cast_transport_.get());
+  on_audio_decoded_cb_ = base::Bind(
+      &CastReceiverSessionDelegate::OnDecodedAudioFrame,
+      weak_factory_.GetWeakPtr());
+  on_video_decoded_cb_ = base::Bind(
+      &CastReceiverSessionDelegate::OnDecodedVideoFrame,
+      weak_factory_.GetWeakPtr());
+}
+
+void CastReceiverSessionDelegate::StartAudio(AudioCB audio_callback) {
+  DCHECK(io_message_loop_proxy_->BelongsToCurrentThread());
+  audio_callback_ = audio_callback;
+  cast_receiver_->RequestDecodedAudioFrame(on_audio_decoded_cb_);
+}
+
+void  CastReceiverSessionDelegate::StopAudio(base::WaitableEvent* event) {
+  audio_callback_ = AudioCB();
+  cast_environment_->PostTask(media::cast::CastEnvironment::AUDIO,
+                              FROM_HERE,
+                              base::Bind(&base::WaitableEvent::Signal,
+                                         base::Unretained(event)));
+}
+
+void CastReceiverSessionDelegate::OnDecodedAudioFrame(
+    scoped_ptr<media::AudioBus> audio_bus,
+    const base::TimeTicks& playout_time,
+    bool is_continous) {
+  if (audio_callback_.is_null())
+    return;
+
+  // We're on the IO thread, which doesn't allow blocking
+  // operations. Since we don't know what the Capture callback
+  // will do exactly, we need to jump to a different thread.
+  // Let's re-use the audio decoder thread.
+  base::TimeTicks now = cast_environment_->Clock()->NowTicks();
+  cast_environment_->PostTask(
+      media::cast::CastEnvironment::AUDIO,
+      FROM_HERE,
+      base::Bind(audio_callback_,
+                 base::Owned(audio_bus.release()),
+                 (playout_time - now).InMilliseconds(),
+                 1.0,
+                 false));
+  cast_receiver_->RequestDecodedAudioFrame(on_audio_decoded_cb_);
+}
+
+void CastReceiverSessionDelegate::StartVideo(
+    content::VideoCaptureDeliverFrameCB video_callback) {

[Alpha Left Google, 2015/02/04 03:07:52]

This callback passed from CastVideoCapturerSource must be called from the IO
thread, which is unknown to the interface of VideoCapturerSource. I think this
method should take a MessageLoopProxy and then perform a DCHECK in
OnDecodedVideoFrame to verify the callback is called on the correct thread.

[hubbe, 2015/02/05 20:23:00]

Done.

+  DCHECK(io_message_loop_proxy_->BelongsToCurrentThread());
+  frame_callback_ = video_callback;
+  cast_receiver_->RequestDecodedVideoFrame(on_video_decoded_cb_);
+}
+

[Alpha Left Google, 2015/02/04 03:07:52]

nit: empty line.

[hubbe, 2015/02/05 20:23:00]

Done.

+
+void  CastReceiverSessionDelegate::StopVideo(base::WaitableEvent* event) {
+  frame_callback_ = content::VideoCaptureDeliverFrameCB();
+  event->Signal();
+}
+
+void CastReceiverSessionDelegate::OnDecodedVideoFrame(
+    const scoped_refptr<media::VideoFrame>& video_frame,
+    const base::TimeTicks& playout_time,
+    bool is_continous) {
+  if (frame_callback_.is_null())
+    return;
+  frame_callback_.Run(video_frame, format_, playout_time);
+  cast_receiver_->RequestDecodedVideoFrame(on_video_decoded_cb_);
+}