[chrome.displaySource][WiFi Display] Media pipeline infrastructure

extensions/renderer/api/display_source/wifi_display/wifi_display_media_manager.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 "extensions/renderer/api/display_source/wifi_display/wifi_display_media_manager.h"
 
 #include "base/logging.h"
 #include "base/rand_util.h"
+#include "base/task_runner_util.h"
 #include "content/public/renderer/media_stream_utils.h"
+#include "content/public/renderer/media_stream_video_sink.h"
+#include "content/public/renderer/render_thread.h"
+#include "content/public/renderer/video_encode_accelerator.h"
+#include "extensions/common/mojo/wifi_display_session_service.mojom.h"
+#include "extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_info.h"
+#include "extensions/renderer/api/display_source/wifi_display/wifi_display_media_pipeline.h"
+#include "media/base/bind_to_current_loop.h"
 
 namespace extensions {
 
 namespace {
 
 const char kErrorNoVideoFormatData[] =
     "Failed to get video format data from the given MediaStreamTrack object";
 const char kErrorSinkCannotPlayVideo[] =
     "The sink cannot play video from the given MediaStreamTrack object";
 const char kErrorSinkCannotPlayAudio[] =
     "The sink cannot play audio from the given MediaStreamTrack object";
+const char kErrorMediaPipelineFailure[] =
+    "Failed to initialize media pipeline for the session";
 }  // namespace
 
+class WiFiDisplayVideoSink : public content::MediaStreamVideoSink {
+ public:
+  WiFiDisplayVideoSink(
+      const blink::WebMediaStreamTrack& track,
+      const content::VideoCaptureDeliverFrameCB& callback)
+      : track_(track),
+        sink_added_(false),
+        callback_(callback) {
+  }
+
+  ~WiFiDisplayVideoSink() override {
+    Stop();
+  }
+
+  void Start() {
+    DCHECK(!sink_added_);
+    sink_added_ = true;
+    // Callback is invoked on IO thread.
+    AddToVideoTrack(this, callback_, track_);
+  }
+
+  void Stop() {
+    if (sink_added_)
+      RemoveFromVideoTrack(this, track_);
+  }
+
+ private:
+  blink::WebMediaStreamTrack track_;
+  bool sink_added_;
+  content::VideoCaptureDeliverFrameCB callback_;
+  DISALLOW_COPY_AND_ASSIGN(WiFiDisplayVideoSink);
+};
+
 WiFiDisplayMediaManager::WiFiDisplayMediaManager(
     const blink::WebMediaStreamTrack& video_track,
     const blink::WebMediaStreamTrack& audio_track,
     const ErrorCallback& error_callback)
   : video_track_(video_track),
     audio_track_(audio_track),
-    error_callback_(error_callback) {
+    player_(nullptr),
+    io_task_runner_(content::RenderThread::Get()->GetIOMessageLoopProxy()),
+    error_callback_(error_callback),
+    is_playing_(false),
+    is_initialized_(false),
+    weak_factory_(this) {
   DCHECK(!video_track.isNull() || !audio_track.isNull());
   DCHECK(!error_callback_.is_null());
 }
 
 WiFiDisplayMediaManager::~WiFiDisplayMediaManager() {
+  Teardown();
 }
 
 void WiFiDisplayMediaManager::Play() {
-  NOTIMPLEMENTED();
+  is_playing_ = true;
+  if (!player_) {
+    base::PostTaskAndReplyWithResult(io_task_runner_.get(), FROM_HERE,
+        base::Bind(
+            &WiFiDisplayMediaPipeline::Create,
+            GetSessionType(),
+            video_encoder_parameters_,
+            optimal_audio_codec_,
+            media::BindToCurrentLoop(error_callback_)),
+        base::Bind(&WiFiDisplayMediaManager::OnPlayerCreated,
+                   weak_factory_.GetWeakPtr()));
+    return;
+  }
+
+  if (!is_initialized_) {
+    return;  // Waiting for initialization being completed.
+  }
+
+  if (!video_track_.isNull()) {
+    // To be called on IO thread.
+    auto on_raw_video_frame = base::Bind(
+        &WiFiDisplayMediaPipeline::InsertRawVideoFrame,
+        base::Unretained(player_));
+    video_sink_.reset(
+        new WiFiDisplayVideoSink(video_track_, on_raw_video_frame));
+    video_sink_->Start();
+    LOG(ERROR) << "video sink started";
+  }
 }
 
 void WiFiDisplayMediaManager::Teardown() {
-  NOTIMPLEMENTED();
+  Pause();
+  if (player_) {
+    io_task_runner_->DeleteSoon(FROM_HERE, player_);
+    player_ = nullptr;
+  }
+  is_initialized_ = false;
+  session_id_.clear();
 }
 
 void WiFiDisplayMediaManager::Pause() {
-  NOTIMPLEMENTED();
+  is_playing_ = false;
+  video_sink_.reset();
 }
 
 bool WiFiDisplayMediaManager::IsPaused() const {
-  NOTIMPLEMENTED();
-  return true;
+  return !is_playing_;
 }
 
 wds::SessionType WiFiDisplayMediaManager::GetSessionType() const {
   uint16_t session_type = 0;
   if (!video_track_.isNull())
     session_type |= wds::VideoSession;
 
   if (!audio_track_.isNull())
     session_type |= wds::AudioSession;
 
@@ skipping 124 matching lines @@
   }
   return false;
 }
 
 }  // namespace
 
 wds::H264VideoFormat WiFiDisplayMediaManager::GetOptimalVideoFormat() const {
   return optimal_video_format_;
 }
 
-void WiFiDisplayMediaManager::SendIDRPicture() {
-  NOTIMPLEMENTED();
+namespace {
+
+int GetBitRate(const gfx::Size& frame_size) {
+  DCHECK_GE(frame_size.height(), 360);
+  if (frame_size.height() < 720)
+    return 2500000;
+  if (frame_size.height() < 1080)
+    return 5000000;
+  return 8000000;
 }
 
-std::string WiFiDisplayMediaManager::GetSessionId() const {
-  return base::RandBytesAsString(8);
+void CreateVideoEncodeMemory(
+    size_t size,
+    const WiFiDisplayVideoEncoder::ReceiveEncodeMemoryCallback& callback) {
+  DCHECK(content::RenderThread::Get());
+
+  scoped_ptr<base::SharedMemory> shm =
+      content::RenderThread::Get()->HostAllocateSharedMemoryBuffer(size);
+  DCHECK(shm) << "Failed to allocate shared memory";

[asargent_no_longer_on_chrome, 2016/04/06 20:53:21]

Maybe this should just be a CHECK?

Alternately, maybe you should consider gracefully handling the error? I guess it
depends on whether it's possible to fail in a more user-friendly way than just
having the renderer process die. 

I took a quick glance and saw a bunch of consumers of
HostAllocateSharedMemoryBuffer doing graceful error handling, which makes me
wonder if this might be more likely than a standard allocation (of reasonable
size) to fail. 

Does code elsewhere do any sanity checking on the value you're passing as |size|
here?

[Mikhail, 2016/04/07 09:07:25]

We can just pass nullptr to encoder that will be able to report an error in a
graceful way via error callback.

+  if (!shm->Map(size)) {
+    NOTREACHED() << "Map failed";
+  }
+  callback.Run(std::move(shm));
 }
 
+}  // namespace
+
 bool WiFiDisplayMediaManager::InitOptimalVideoFormat(
     const wds::NativeVideoFormat& sink_native_format,
     const std::vector<wds::H264VideoCodec>& sink_supported_codecs) {
   const media::VideoCaptureFormat* capture_format =
       content::GetCurrentVideoTrackFormat(video_track_);
   if (!capture_format) {
     error_callback_.Run(kErrorNoVideoFormatData);
     return false;
   }
 
   if (!FindOptimalFormat(
       capture_format, sink_supported_codecs, &optimal_video_format_)) {
     error_callback_.Run(kErrorSinkCannotPlayVideo);
     return false;
   }
+  video_encoder_parameters_.frame_size = capture_format->frame_size;
+  video_encoder_parameters_.frame_rate =
+      static_cast<int>(capture_format->frame_rate);
+  video_encoder_parameters_.bit_rate = GetBitRate(capture_format->frame_size);
+  video_encoder_parameters_.profile = optimal_video_format_.profile;
+  video_encoder_parameters_.level = optimal_video_format_.level;
+  video_encoder_parameters_.create_memory_callback =
+      media::BindToCurrentLoop(base::Bind(&CreateVideoEncodeMemory));
+  video_encoder_parameters_.vea_create_callback =
+      media::BindToCurrentLoop(
+          base::Bind(&content::CreateVideoEncodeAccelerator));
 
   return true;
 }
 
 bool WiFiDisplayMediaManager::InitOptimalAudioFormat(
     const std::vector<wds::AudioCodec>& sink_codecs) {
   for (const wds::AudioCodec& codec : sink_codecs) {
     // MediaStreamTrack contains LPCM audio.
     if (codec.format == wds::LPCM) {
       optimal_audio_codec_ = codec;
       // Picking a single mode.
       wds::AudioModes optimal_mode;
       if (codec.modes.test(wds::LPCM_44_1K_16B_2CH))
         optimal_mode.set(wds::LPCM_44_1K_16B_2CH);
       else
         optimal_mode.set(wds::LPCM_48K_16B_2CH);
       optimal_audio_codec_.modes = optimal_mode;
       return true;
     }
   }
   error_callback_.Run(kErrorSinkCannotPlayAudio);
   return false;
 }
 
 wds::AudioCodec WiFiDisplayMediaManager::GetOptimalAudioFormat() const {
   return optimal_audio_codec_;
 }
 
+void WiFiDisplayMediaManager::SendIDRPicture() {
+  DCHECK(player_);
+  io_task_runner_->PostTask(FROM_HERE,
+      base::Bind(&WiFiDisplayMediaPipeline::RequestIDRPicture,
+                 base::Unretained(player_)));
+}
+
+std::string WiFiDisplayMediaManager::GetSessionId() const {
+  if (session_id_.empty())
+    session_id_ = base::RandBytesAsString(8);
+  return session_id_;
+}
+
+void WiFiDisplayMediaManager::OnPlayerCreated(
+    scoped_ptr<WiFiDisplayMediaPipeline> player) {
+  DCHECK(player);
+  DCHECK(content::RenderThread::Get());
+  player_ = player.release();
+
+  auto completion_callback = base::Bind(
+     &WiFiDisplayMediaManager::OnMediaPipelineInitialized,
+     weak_factory_.GetWeakPtr());
+
+  io_task_runner_->PostTask(FROM_HERE,
+      base::Bind(&WiFiDisplayMediaPipeline::Initialize,
+                 base::Unretained(player_),
+                 media::BindToCurrentLoop(completion_callback)));
+}
+
+void WiFiDisplayMediaManager::OnMediaPipelineInitialized(bool success) {
+  DCHECK(content::RenderThread::Get());
+  is_initialized_ = success;
+
+  if (!is_initialized_) {
+    error_callback_.Run(kErrorMediaPipelineFailure);
+    return;
+  }
+
+  if (is_playing_)
+    Play();
+}
+
+
 }  // namespace extensions