Add watch time metrics for HTML5 media playback.

media/blink/webmediaplayer_impl.cc

 // Copyright 2013 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/blink/webmediaplayer_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 #include <string>
@@ skipping 19 matching lines @@
 #include "media/audio/null_audio_sink.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/base/cdm_context.h"
 #include "media/base/limits.h"
 #include "media/base/media_log.h"
 #include "media/base/media_switches.h"
 #include "media/base/text_renderer.h"
 #include "media/base/timestamp_constants.h"
 #include "media/base/video_frame.h"
 #include "media/blink/texttrack_impl.h"
+#include "media/blink/watch_time_reporter.h"
 #include "media/blink/webaudiosourceprovider_impl.h"
 #include "media/blink/webcontentdecryptionmodule_impl.h"
 #include "media/blink/webinbandtexttrack_impl.h"
 #include "media/blink/webmediaplayer_delegate.h"
 #include "media/blink/webmediaplayer_util.h"
 #include "media/blink/webmediasource_impl.h"
 #include "media/filters/chunk_demuxer.h"
 #include "media/filters/ffmpeg_demuxer.h"
 #include "third_party/WebKit/public/platform/WebEncryptedMediaTypes.h"
 #include "third_party/WebKit/public/platform/WebMediaPlayerClient.h"
@@ skipping 72 matching lines @@
   DCHECK_EQ(state > blink::WebMediaPlayer::NetworkStateLoaded, result);
   return result;
 }
 
 gfx::Size GetRotatedVideoSize(VideoRotation rotation, gfx::Size natural_size) {
   if (rotation == VIDEO_ROTATION_90 || rotation == VIDEO_ROTATION_270)
     return gfx::Size(natural_size.height(), natural_size.width());
   return natural_size;
 }
 
+base::TimeDelta GetCurrentTimeInternal(WebMediaPlayerImpl* p_this) {
+  // We wrap currentTime() instead of using pipeline_.GetMediaTime() since there
+  // are a variety of cases in which that time is not accurate.

[sandersd (OOO until July 31), 2016/08/03 22:45:59]

Can you expand on those cases here? (That said, currentTime() is the publicly
exposed information, it's not surprising that it's the correct one to use.)

[DaleCurtis, 2016/08/04 19:14:59]

Done.

+  return base::TimeDelta::FromSecondsD(p_this->currentTime());
+}
+
 }  // namespace
 
 class BufferedDataSourceHostImpl;
 
 STATIC_ASSERT_ENUM(WebMediaPlayer::CORSModeUnspecified,
                    UrlData::CORS_UNSPECIFIED);
 STATIC_ASSERT_ENUM(WebMediaPlayer::CORSModeAnonymous, UrlData::CORS_ANONYMOUS);
 STATIC_ASSERT_ENUM(WebMediaPlayer::CORSModeUseCredentials,
                    UrlData::CORS_USE_CREDENTIALS);
 
@@ skipping 64 matching lines @@
       is_cdm_attached_(false),
 #if defined(OS_ANDROID)  // WMPI_CAST
       cast_impl_(this, client_, params.context_3d_cb()),
 #endif
       volume_(1.0),
       volume_multiplier_(1.0),
       renderer_factory_(std::move(renderer_factory)),
       surface_manager_(params.surface_manager()),
       overlay_surface_id_(SurfaceManager::kNoSurfaceID),
       suppress_destruction_errors_(false),
-      can_suspend_state_(CanSuspendState::UNKNOWN) {
+      can_suspend_state_(CanSuspendState::UNKNOWN),
+      is_encrypted_(false) {
   DCHECK(!adjust_allocated_memory_cb_.is_null());
   DCHECK(renderer_factory_);
   DCHECK(client_);
 
   force_video_overlays_ = base::CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kForceVideoOverlays);
 
   if (delegate_)
     delegate_id_ = delegate_->AddObserver(this);
 
@@ skipping 160 matching lines @@
   }
 #endif
 
   paused_ = false;
   is_idle_ = false;
   pipeline_.SetPlaybackRate(playback_rate_);
 
   if (data_source_)
     data_source_->MediaIsPlaying();
 
+  watch_time_reporter_->OnPlaying();
   media_log_->AddEvent(media_log_->CreateEvent(MediaLogEvent::PLAY));
   UpdatePlayState();
 }
 
 void WebMediaPlayerImpl::pause() {
   DVLOG(1) << __func__;
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
   // We update the paused state even when casting, since we expect pause() to be
   // called when casting begins, and when we exit casting we should end up in a
   // paused state.
   paused_ = true;
 
 #if defined(OS_ANDROID)  // WMPI_CAST
   if (isRemote()) {
     cast_impl_.pause();
     return;
   }
 #endif
 
   pipeline_.SetPlaybackRate(0.0);
 
   // pause() may be called after playback has ended and the HTMLMediaElement
   // requires that currentTime() == duration() after ending.  We want to ensure
   // |paused_time_| matches currentTime() in this case or a future seek() may
   // incorrectly discard what it thinks is a seek to the existing time.
   paused_time_ =
       ended_ ? pipeline_.GetMediaDuration() : pipeline_.GetMediaTime();
 
+  watch_time_reporter_->OnPaused();
   media_log_->AddEvent(media_log_->CreateEvent(MediaLogEvent::PAUSE));
   UpdatePlayState();
 }
 
 bool WebMediaPlayerImpl::supportsSave() const {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   return supports_save_;
 }
 
 void WebMediaPlayerImpl::seek(double seconds) {
@@ skipping 30 matching lines @@
     // completed just by restoring it. Otherwise we will just wait for the real
     // ready state change to eventually happen.
     if (old_state == ReadyStateHaveEnoughData) {
       main_task_runner_->PostTask(
           FROM_HERE, base::Bind(&WebMediaPlayerImpl::OnBufferingStateChange,
                                 AsWeakPtr(), BUFFERING_HAVE_ENOUGH));
     }
     return;
   }
 
+  // Call this before setting |seeking_| so that the current media time can be
+  // recorded by the reporter.
+  watch_time_reporter_->OnSeeking(time);
+
   // TODO(sandersd): Ideally we would not clear the idle state if
   // |pipeline_controller_| can elide the seek.
   is_idle_ = false;
   ended_ = false;
 
   seeking_ = true;
   seek_time_ = time;
   if (paused_)
     paused_time_ = time;
   pipeline_controller_.Seek(time, time_updated);
@@ skipping 26 matching lines @@
     if (data_source_)
       data_source_->MediaPlaybackRateChanged(rate);
   }
 }
 
 void WebMediaPlayerImpl::setVolume(double volume) {
   DVLOG(1) << __func__ << "(" << volume << ")";
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   volume_ = volume;
   pipeline_.SetVolume(volume_ * volume_multiplier_);
+  if (watch_time_reporter_)
+    watch_time_reporter_->OnVolumeChange(volume);
 }
 
 void WebMediaPlayerImpl::setSinkId(
     const blink::WebString& sink_id,
     const blink::WebSecurityOrigin& security_origin,
     blink::WebSetSinkIdCallbacks* web_callback) {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   DVLOG(1) << __func__;
 
   media::OutputDeviceStatusCB callback =
@@ skipping 332 matching lines @@
 }
 
 void WebMediaPlayerImpl::OnEncryptedMediaInitData(
     EmeInitDataType init_data_type,
     const std::vector<uint8_t>& init_data) {
   DCHECK(init_data_type != EmeInitDataType::UNKNOWN);
 
   // TODO(xhwang): Update this UMA name. https://crbug.com/589251
   UMA_HISTOGRAM_COUNTS("Media.EME.NeedKey", 1);
 
+  is_encrypted_ = true;
   encrypted_client_->encrypted(
       ConvertToWebInitDataType(init_data_type), init_data.data(),
       base::saturated_cast<unsigned int>(init_data.size()));
 }
 
 void WebMediaPlayerImpl::OnFFmpegMediaTracksUpdated(
     std::unique_ptr<MediaTracks> tracks) {
   // For MSE/chunk_demuxer case the media track updates are handled by
   // WebSourceBufferImpl.
   DCHECK(demuxer_.get());
@@ skipping 132 matching lines @@
   // expected to be a no-op.
   UpdatePlayState();
 }
 
 void WebMediaPlayerImpl::OnMetadata(PipelineMetadata metadata) {
   DVLOG(1) << __func__;
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
   pipeline_metadata_ = metadata;
 
+  SetReadyState(WebMediaPlayer::ReadyStateHaveMetadata);
   UMA_HISTOGRAM_ENUMERATION("Media.VideoRotation", metadata.video_rotation,
                             VIDEO_ROTATION_MAX + 1);
-  SetReadyState(WebMediaPlayer::ReadyStateHaveMetadata);
 
   if (hasVideo()) {
     pipeline_metadata_.natural_size = GetRotatedVideoSize(
         pipeline_metadata_.video_rotation, pipeline_metadata_.natural_size);
 
     if (overlay_enabled_ && surface_manager_)
       surface_manager_->NaturalSizeChanged(pipeline_metadata_.natural_size);
 
     DCHECK(!video_weblayer_);
     video_weblayer_.reset(new cc_blink::WebLayerImpl(cc::VideoLayer::Create(
         compositor_, pipeline_metadata_.video_rotation)));
     video_weblayer_->layer()->SetContentsOpaque(opaque_);
     video_weblayer_->SetContentsOpaqueIsFixed(true);
     client_->setWebLayer(video_weblayer_.get());
   }
 
+  // Create the watch time reporter and synchronize its initial state.
+  watch_time_reporter_.reset(
+      new WatchTimeReporter(hasAudio(), hasVideo(), !!chunk_demuxer_,
+                            is_encrypted_, pipeline_metadata_.natural_size,
+                            base::Bind(&GetCurrentTimeInternal, this)));

[sandersd (OOO until July 31), 2016/08/03 22:45:59]

What's the reason to not just directly bind currentTime?

[DaleCurtis, 2016/08/04 19:14:59]

The detail of currentTime returning a double is specific to the blink layer and
shouldn't leak into other components (they should use TimeDelta).

+  watch_time_reporter_->OnVolumeChange(volume_);
+  if (delegate_ && delegate_->IsHidden())
+    watch_time_reporter_->OnHidden();
+  else
+    watch_time_reporter_->OnShown();
+
   UpdatePlayState();
 }
 
 void WebMediaPlayerImpl::OnBufferingStateChange(BufferingState state) {
   DVLOG(1) << __func__ << "(" << state << ")";
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
   // Ignore buffering state changes until we've completed all outstanding
   // operations.
   if (!pipeline_controller_.IsStable())
@@ skipping 98 matching lines @@
 
   opaque_ = opaque;
   // Modify content opaqueness of cc::Layer directly so that
   // SetContentsOpaqueIsFixed is ignored.
   if (video_weblayer_)
     video_weblayer_->layer()->SetContentsOpaque(opaque_);
 }
 
 void WebMediaPlayerImpl::OnHidden() {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
+  if (watch_time_reporter_)
+    watch_time_reporter_->OnHidden();
+
   UpdatePlayState();
 
   // Schedule suspended playing media to be paused if the user doesn't come back
   // to it within some timeout period to avoid any autoplay surprises.
   ScheduleIdlePauseTimer();
 }
 
 void WebMediaPlayerImpl::OnShown() {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
+  if (watch_time_reporter_)
+    watch_time_reporter_->OnShown();
+
   must_suspend_ = false;
   background_pause_timer_.Stop();
   UpdatePlayState();
 }
 
 void WebMediaPlayerImpl::OnSuspendRequested(bool must_suspend) {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
   if (must_suspend) {
     must_suspend_ = true;
@@ skipping 544 matching lines @@
   if (isRemote())
     return;
 #endif
 
   // Idle timeout chosen arbitrarily.
   background_pause_timer_.Start(FROM_HERE, base::TimeDelta::FromSeconds(5),
                                 this, &WebMediaPlayerImpl::OnPause);
 }
 
 }  // namespace media