WIP - WebMediaPlayer switch media renderer.

media/remoting/remoting_controller.cc

+// Copyright 2016 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/remoting/remoting_controller.h"
+
+#include "base/bind.h"
+#include "media/base/bind_to_current_loop.h"
+
+namespace media {
+
+RemotingController::RemotingController(mojom::RemoterFactory* remoter_factory)
+    : is_fullscreen_(false),
+      is_sink_available_(false),
+      use_remoting_renderer_(false),
+      binding_(this),
+      task_runner_(base::ThreadTaskRunnerHandle::Get()) {
+  remoter_factory->Create(binding_.CreateInterfacePtrAndBind(),

[miu, 2016/09/28 07:23:09]

This issue came up on Eric's change: We should be doing the mojo binding on the
IO thread instead of the main thread. This is important because we have objects
on two different threads (the main thread and the media thread) that want to
make and receive IPC calls through the mojo interface. There's also a concern
that the main thread can block for long periods of time (e.g., if the page runs
JavaScript in an infinite loop).

So, for all calls to |remoter_|, we'll need to:

  io_thread_task_runner_->PostTask(...remoter_->MethodCall() here...);

...and, all methods in this class that implement media::mojom::RemotingSource
will get called on the IO thread. Other than OnMessageFromSink(), the method
calls will have to trampoline back to the main thread to call your Update()
method.

...and, finally, at destruction time, the |binding_.Unbind()| will have to occur
on the IO thread.

[xjz, 2016/09/29 22:54:22]

As discussed offline, keep this on main thread for now.

+                          mojo::GetProxy(&remoter_));
+}
+
+RemotingController::~RemotingController() {}
+
+void RemotingController::OnSinkAvailable() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  is_sink_available_ = true;
+  Update();
+}
+
+void RemotingController::OnSinkGone() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  is_sink_available_ = false;
+  Update();
+}
+
+void RemotingController::OnStarted() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  VLOG(1) << "Remoting started successively.";
+  if (use_remoting_renderer_) {
+    if (!switch_renderer_cb_.is_null())
+      switch_renderer_cb_.Run();
+  } else {
+    remoter_->Stop(mojom::RemotingStopReason::LOCAL_PLAYBACK);
+  }
+}
+
+void RemotingController::OnStartFailed(mojom::RemotingStartFailReason reason) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  VLOG(1) << "Failed to start remoting: " << reason;
+  use_remoting_renderer_ = false;
+}
+
+void RemotingController::OnMessageFromSink(
+    const std::vector<uint8_t>& message) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  // TODO(xjz): Merge with Eric's CL to handle the RPC messages here.
+}
+
+void RemotingController::OnStopped(mojom::RemotingStopReason reason) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  VLOG(1) << "Remoting stopped: " << reason;
+  if (use_remoting_renderer_)
+    remoter_->Start();

[miu, 2016/09/28 01:33:32]

Thinking aloud: Maybe this method should just set use_remoting_renderer_ = false
and wait for other signals (that will call Update()) to set it back to true.
From the user perspective, this would require them to, say, leave and re-enter
fullscreen mode before we attempt to start Remoting again.

[xjz, 2016/09/29 22:54:22]

Done.

+}
+
+void RemotingController::OnEnteredFullscreen() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  is_fullscreen_ = true;
+  Update();
+}
+
+void RemotingController::OnExitedFullscreen() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  is_fullscreen_ = false;
+  Update();
+}
+
+void RemotingController::OnSetCdm(CdmContext* cdm_context) {
+  // TODO(xjz): Not implemented. Will add in up-coming change.

[miu, 2016/09/28 01:33:32]

Note: Please use the NOTIMPLEMENTED() logging macro here. It'll log a warning to
remind us.

[xjz, 2016/09/29 22:54:22]

Done.

+}
+
+void RemotingController::SetSwitchRenderCallback(
+    const RendererController::SwitchRendererCallback& cb) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  DCHECK(!cb.is_null());
+
+  switch_renderer_cb_ = BindToCurrentLoop(cb);
+}
+
+void RemotingController::OnSetDecoderConfig(
+    const AudioDecoderConfig& audio_config,
+    const VideoDecoderConfig& video_config) {
+  audio_decoder_config_ = audio_config;

[miu, 2016/09/28 01:33:32]

Please add DCHECK(task_runner->Belongs()) here.

BTW--Nice that you found a way to do this on the main thread! :)

[xjz, 2016/09/29 22:54:21]

Done.

+  video_decoder_config_ = video_config;
+  Update();
+}
+
+bool RemotingController::isVideoConfigSupported() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  if (!video_decoder_config_.IsValidConfig())
+    return false;
+
+  switch (video_decoder_config_.codec()) {
+    case VideoCodec::kCodecH264:
+    case VideoCodec::kCodecVP8:
+      return true;
+    default:
+      VLOG(2) << "Remoting does not support video codec: "
+              << video_decoder_config_.codec();
+      return false;
+  }
+}
+
+bool RemotingController::isAudioConfigSupported() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  if (!audio_decoder_config_.IsValidConfig())
+    return false;
+
+  switch (audio_decoder_config_.codec()) {
+    case AudioCodec::kCodecAAC:
+    case AudioCodec::kCodecMP3:
+    case AudioCodec::kCodecPCM:
+    case AudioCodec::kCodecVorbis:
+    case AudioCodec::kCodecFLAC:
+    case AudioCodec::kCodecAMR_NB:
+    case AudioCodec::kCodecAMR_WB:
+    case AudioCodec::kCodecPCM_MULAW:
+    case AudioCodec::kCodecGSM_MS:
+    case AudioCodec::kCodecPCM_S16BE:
+    case AudioCodec::kCodecPCM_S24BE:
+    case AudioCodec::kCodecOpus:
+    case AudioCodec::kCodecEAC3:
+    case AudioCodec::kCodecPCM_ALAW:
+    case AudioCodec::kCodecALAC:
+    case AudioCodec::kCodecAC3:
+      return true;
+    default:
+      VLOG(2) << "Remoting does not support audio codec: "
+              << audio_decoder_config_.codec();
+      return false;
+  }
+}
+
+void RemotingController::Update() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  // TODO(xjz): The swithcing logic for encrypted content will be added in a

[miu, 2016/09/28 01:33:32]

typo: s/swithcing/switching/

[xjz, 2016/09/29 22:54:21]

Done.

+  // later CL.
+  if (video_decoder_config_.is_encrypted())

[miu, 2016/09/28 01:33:32]

Instead of returning early, I'd suggest you add it to the "should" boolean
below.

  bool should_be_remoting = ... && !video_decoder_config_.is_encrypted();

[xjz, 2016/09/29 22:54:22]

Done.

+    return;
+
+  bool should_remoting = is_sink_available_ && is_fullscreen_ &&

[miu, 2016/09/28 01:33:32]

naming: should_be_remoting

[xjz, 2016/09/29 22:54:21]

Done.

+                         isVideoConfigSupported() && isAudioConfigSupported();
+  if (use_remoting_renderer_ == should_remoting)
+    return;
+
+  // Switch between local and remoting.
+  use_remoting_renderer_ = should_remoting;
+  if (use_remoting_renderer_) {
+    remoter_->Start();
+  } else {
+    if (!switch_renderer_cb_.is_null())

[miu, 2016/09/28 01:33:32]

In the "should" boolean above, I'd suggest adding:

  bool should_be_remoting = ... && !switch_renderer_cb.is_null();

(So that we never try to call remoter_->Start() if the callback is missing.)

[xjz, 2016/09/29 22:54:22]

Done.

+      switch_renderer_cb_.Run();
+    // TODO(xjz): Send RPC message to notify ChromeCast.
+    remoter_->Stop(mojom::RemotingStopReason::LOCAL_PLAYBACK);
+  }
+}
+
+bool RemotingController::ShouldUseRemotingRenderer() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  return use_remoting_renderer_;
+}
+
+}  // namespace media