Cast: Basic cast_receiver API for chrome.

chrome/renderer/media/cast_receiver_session.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.h"
+
+#include "base/synchronization/waitable_event.h"
+#include "content/public/renderer/media_stream_source_api.h"
+#include "content/public/renderer/render_thread.h"
+#include "media/base/audio_capturer_source.h"
+#include "media/video/capture/video_capturer_source.h"
+#include "third_party/WebKit/public/platform/WebMediaStream.h"
+#include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
+#include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
+
+class CastStreamingAudioCaptureSource : public media::AudioCapturerSource {

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

Should be CastSreamingAudioCapturerSource.

[hubbe, 2015/02/05 20:22:59]

Done.

+ public:
+  CastStreamingAudioCaptureSource(
+      scoped_refptr<CastReceiverSession> cast_receiver_session);
+  void Initialize(const media::AudioParameters& params,
+                  CaptureCallback* callback,
+                  int session_id) override;
+  void Start() override;
+  void Stop() override;
+  void SetVolume(double volume) override;
+  void SetAutomaticGainControl(bool enable) override;
+ private:
+  ~CastStreamingAudioCaptureSource() override;
+  scoped_refptr<CastReceiverSession> cast_receiver_session_;
+  CaptureCallback* capture_callback_;   // Ownership??
+};
+
+class CastVideoCapturerSource : public media::VideoCapturerSource {

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

Should be CastStreamingvideoCapturerSource to be consistent.

[hubbe, 2015/02/05 20:22:59]

Done.

+ public:
+  explicit CastVideoCapturerSource(
+            scoped_refptr<CastReceiverSession> cast_receiver_session);
+ protected:
+  void GetCurrentSupportedFormats(
+      int max_requested_width,
+      int max_requested_height,
+      double max_requested_frame_rate,
+      const VideoCaptureDeviceFormatsCB& callback) override;
+  void StartCapture(
+      const media::VideoCaptureParams& params,
+      const content::VideoCaptureDeliverFrameCB& frame_callback,
+      const RunningCallback& running_callback) override;
+  void StopCapture() override;
+ private:
+  ~CastVideoCapturerSource() override;
+  scoped_refptr<CastReceiverSession> cast_receiver_session_;
+};
+
+CastReceiverSession::CastReceiverSession()
+    : delegate_(new CastReceiverSessionDelegate()),
+      io_message_loop_proxy_(
+          content::RenderThread::Get()->GetIOMessageLoopProxy()) {}
+
+CastReceiverSession::~CastReceiverSession() {
+  // We should always be able to delete the object on the IO thread.
+  CHECK(io_message_loop_proxy_->DeleteSoon(FROM_HERE, delegate_.release()));
+}
+
+void CastReceiverSession::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& capture_format,
+    const StartCB& start_callback) {
+  format_ = capture_format;
+  io_message_loop_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&CastReceiverSessionDelegate::Start,
+                 base::Unretained(delegate_.get()),
+                 audio_config,
+                 video_config,
+                 local_endpoint,
+                 remote_endpoint,
+                 base::Passed(&options),
+                 format_));
+  blink::WebMediaStreamSource video_source;
+  content::InitializeVideoWebMediaSource(new CastVideoCapturerSource(this),
+                                         &video_source);
+  blink::WebVector<blink::WebMediaStreamTrack> video_tracks(
+      static_cast<size_t>(1));
+  video_tracks[0].initialize(video_source);
+
+  blink::WebMediaStreamSource audio_source;
+  content::InitializeAudioWebMediaSource(
+      new CastStreamingAudioCaptureSource(this),
+      &audio_source);
+  blink::WebVector<blink::WebMediaStreamTrack> audio_tracks(
+      static_cast<size_t>(1));
+  audio_tracks[0].initialize(audio_source);
+
+  blink::WebMediaStream stream;
+  stream.initialize(audio_tracks, video_tracks);
+
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE,
+      base::Bind(start_callback, stream));
+}
+
+void CastReceiverSession::StartAudio(
+    CastReceiverSessionDelegate::AudioCB audio_callback) {
+  io_message_loop_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&CastReceiverSessionDelegate::StartAudio,
+                 base::Unretained(delegate_.get()),
+                 audio_callback));
+}
+
+void CastReceiverSession::StopAudio(base::WaitableEvent* event) {
+  io_message_loop_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&CastReceiverSessionDelegate::StopAudio,
+                 base::Unretained(delegate_.get()),
+                 event));
+}
+
+void CastReceiverSession::StartVideo(
+    content::VideoCaptureDeliverFrameCB frame_callback) {
+  io_message_loop_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&CastReceiverSessionDelegate::StartVideo,
+                 base::Unretained(delegate_.get()),
+                 frame_callback));
+}
+
+void CastReceiverSession::StopVideo(base::WaitableEvent* event) {
+  io_message_loop_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&CastReceiverSessionDelegate::StopVideo,
+                 base::Unretained(delegate_.get()),
+                 event));
+}
+
+
+CastVideoCapturerSource::CastVideoCapturerSource(
+    scoped_refptr<CastReceiverSession> cast_receiver_session)
+    : cast_receiver_session_(cast_receiver_session) {
+}
+
+CastVideoCapturerSource::~CastVideoCapturerSource() {}
+
+void CastVideoCapturerSource::GetCurrentSupportedFormats(
+    int max_requested_width,
+    int max_requested_height,
+    double max_requested_frame_rate,
+    const VideoCaptureDeviceFormatsCB& callback) {
+  std::vector<media::VideoCaptureFormat> formats;
+  if (cast_receiver_session_->format().IsValid()) {
+    formats.push_back(cast_receiver_session_->format());
+  }
+  callback.Run(formats);
+}
+
+void CastVideoCapturerSource::StartCapture(
+      const media::VideoCaptureParams& params,
+      const content::VideoCaptureDeliverFrameCB& frame_callback,
+      const RunningCallback& running_callback) {
+  cast_receiver_session_->StartVideo(frame_callback);
+}
+
+void CastVideoCapturerSource::StopCapture() {
+  base::WaitableEvent event(true, false);

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

There is no need to stop and wait. |frame_callback| can be called safely (on IO
thread) even after this method is called.

[hubbe, 2015/02/05 20:22:59]

Done.

+  cast_receiver_session_->StopVideo(&event);
+  event.Wait();
+}
+
+CastStreamingAudioCaptureSource::CastStreamingAudioCaptureSource(
+    scoped_refptr<CastReceiverSession> cast_receiver_session)
+    : cast_receiver_session_(cast_receiver_session) {
+}
+
+CastStreamingAudioCaptureSource::~CastStreamingAudioCaptureSource() {}
+
+void CastStreamingAudioCaptureSource::Initialize(
+    const media::AudioParameters& params,
+    CaptureCallback* callback,
+    int session_id) {
+  if (params.sample_rate() != 48000 ||

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

Need a comment or TODO to fix this limitation.

[hubbe, 2015/02/05 20:22:59]

Improved to not hardcode values and added TODO to consider conversion.

+      params.bits_per_sample() != 16 ||
+      params.channels() != 2) {
+    callback->OnCaptureError();
+    return;
+  }
+  capture_callback_ = callback;
+}
+
+void CastStreamingAudioCaptureSource::Start() {
+  cast_receiver_session_->StartAudio(
+      base::Bind(&media::AudioCapturerSource::CaptureCallback::Capture,
+                 base::Unretained(capture_callback_)));
+}
+
+void CastStreamingAudioCaptureSource::Stop() {
+  base::WaitableEvent event(true, false);

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

Instead of blocking here what about having a third party ref counted thread safe
proxy object that allows you to submit audio data and detach under a lock?

[hubbe, 2015/02/05 20:22:59]

Done.

+  cast_receiver_session_->StopAudio(&event);
+  event.Wait();
+}
+
+void CastStreamingAudioCaptureSource::SetVolume(double volume) {
+  // not supported
+}
+
+void CastStreamingAudioCaptureSource::SetAutomaticGainControl(bool enable) {
+  // not supported
+}