[telemetry] Add telemetry to SbPlayerWriteSamples (#4097)

Adding additional Media Telemetry to cover SbPlayerWriteSamples.

The rough range of each function:
1. When batched write is enabled (Media.MaxAudioSamplesPerWrite=256,
#3271):
    1. SbPlayerWriteSamples()/audio: 1us to 98us
    2. SbPlayerWriteSamples()/video: 1us to 3.4ms
2. When batched write is disabled (Media.MaxAudioSamplesPerWrite=1,
#3271):
    1. SbPlayerWriteSamples()/audio: 9us to 65.47ms
    2. SbPlayerWriteSamples()/video: 8us to 28.07ms

b/303328238

cobalt/media/base/metrics_provider.cc

@@ -122,6 +122,20 @@ void MediaMetricsProvider::EndTrackingAction(MediaAction action) {
   tracked_actions_start_times_.erase(action);
 }
 
+void MediaMetricsProvider::EndTrackingAction(MediaAction action,
+                                             int number_of_samples) {
+  DCHECK(IsActionCurrentlyTracked(action));
+  base::AutoLock scoped_lock(mutex_);
+
+  auto duration = clock_->NowTicks() - tracked_actions_start_times_[action];
+  if (number_of_samples > 0) {
+    // Report latency UMA if it writes non-zero samples.
+    auto duration_per_sample = duration / number_of_samples;
+    ReportActionLatencyUMA(action, duration_per_sample);
+  }
+  tracked_actions_start_times_.erase(action);
+}
+
 bool MediaMetricsProvider::IsActionCurrentlyTracked(MediaAction action) {
   base::AutoLock scoped_lock(mutex_);
   return tracked_actions_start_times_.find(action) !=
@@ -211,6 +225,18 @@ void MediaMetricsProvider::ReportActionLatencyUMA(
           base::TimeDelta::FromMicroseconds(1),
           base::TimeDelta::FromMilliseconds(50), 50);
       break;
+    case MediaAction::SBPLAYER_WRITE_SAMPLES_AUDIO:
+      UMA_HISTOGRAM_CUSTOM_MICROSECONDS_TIMES(
+          "Cobalt.Media.SbPlayer.WriteSamples.Audio.LatencyTiming",
+          action_duration, base::TimeDelta::FromMicroseconds(1),
+          base::TimeDelta::FromMilliseconds(100), 50);
+      break;
+    case MediaAction::SBPLAYER_WRITE_SAMPLES_VIDEO:
+      UMA_HISTOGRAM_CUSTOM_MICROSECONDS_TIMES(
+          "Cobalt.Media.SbPlayer.WriteSamples.Video.LatencyTiming",
+          action_duration, base::TimeDelta::FromMicroseconds(1),
+          base::TimeDelta::FromMilliseconds(100), 50);
+      break;
     case MediaAction::SBDRM_CREATE:
       UMA_HISTOGRAM_CUSTOM_MICROSECONDS_TIMES(
           "Cobalt.Media.SbDrm.Create.LatencyTiming", action_duration,

cobalt/media/base/metrics_provider.h

@@ -54,6 +54,8 @@ enum class MediaAction : uint8_t {
   SBPLAYER_GET_INFO,
   SBPLAYER_GET_CURRENT_FRAME,
   SBPLAYER_GET_AUDIO_CONFIG,
+  SBPLAYER_WRITE_SAMPLES_AUDIO,
+  SBPLAYER_WRITE_SAMPLES_VIDEO,
   SBDRM_CREATE,
   SBDRM_DESTROY,
   SBDRM_GENERATE_SESSION_UPDATE_REQUEST,
@@ -105,6 +107,7 @@ class MediaMetricsProvider {
   // Used to record the latency of an action in the WebMediaPlayer.
   void StartTrackingAction(MediaAction action);
   void EndTrackingAction(MediaAction action);
+  void EndTrackingAction(MediaAction action, int number_of_samples);
   bool IsActionCurrentlyTracked(MediaAction action);
 
   void Reset();

cobalt/media/base/metrics_provider_test.cc

@@ -200,6 +200,28 @@ TEST_F(MediaMetricsProviderTest, SbPlayerWriteEndOfStreamVideo) {
       570, 1);
 }
 
+TEST_F(MediaMetricsProviderTest, SbPlayerWriteSamplesAudio) {
+  metrics_.StartTrackingAction(MediaAction::SBPLAYER_WRITE_SAMPLES_AUDIO);
+
+  clock_.Advance(base::TimeDelta::FromMicroseconds(570));
+  metrics_.EndTrackingAction(MediaAction::SBPLAYER_WRITE_SAMPLES_AUDIO);
+
+  histogram_tester_.ExpectUniqueSample(
+      std::string(kUmaPrefix) + "SbPlayer.WriteSamples.Audio.LatencyTiming",
+      570, 1);
+}
+
+TEST_F(MediaMetricsProviderTest, SbPlayerWriteSamplesVideoAudio) {
+  metrics_.StartTrackingAction(MediaAction::SBPLAYER_WRITE_SAMPLES_VIDEO);
+
+  clock_.Advance(base::TimeDelta::FromMicroseconds(570));
+  metrics_.EndTrackingAction(MediaAction::SBPLAYER_WRITE_SAMPLES_VIDEO);
+
+  histogram_tester_.ExpectUniqueSample(
+      std::string(kUmaPrefix) + "SbPlayer.WriteSamples.Video.LatencyTiming",
+      570, 1);
+}
+
 TEST_F(MediaMetricsProviderTest, SbDrmCloseSession) {
   metrics_.StartTrackingAction(MediaAction::SBDRM_CLOSE_SESSION);
 

cobalt/media/base/sbplayer_interface.cc

@@ -113,13 +113,19 @@ void DefaultSbPlayerInterface::WriteSamples(
     SbPlayer player, SbMediaType sample_type,
     const SbPlayerSampleInfo* sample_infos, int number_of_sample_infos) {
   DCHECK(!IsEnhancedAudioExtensionEnabled());
+  auto media_action = (sample_type == kSbMediaTypeAudio)
+                          ? MediaAction::SBPLAYER_WRITE_SAMPLES_AUDIO
+                          : MediaAction::SBPLAYER_WRITE_SAMPLES_VIDEO;
+  media_metrics_provider_.StartTrackingAction(media_action);
 #if SB_API_VERSION >= 15
   SbPlayerWriteSamples(player, sample_type, sample_infos,
                        number_of_sample_infos);
 #else   // SB_API_VERSION >= 15
   SbPlayerWriteSample2(player, sample_type, sample_infos,
                        number_of_sample_infos);
 #endif  // SB_API_VERSION >= 15
+  media_metrics_provider_.EndTrackingAction(media_action,
+                                            number_of_sample_infos);
 }
 
 void DefaultSbPlayerInterface::WriteSamples(

tools/metrics/histograms/metadata/cobalt/histograms.xml

@@ -494,6 +494,24 @@ Always run the pretty print utility on this file after editing:
   <summary>Timing data for writing end of video stream.</summary>
 </histogram>
 
+<histogram name="Cobalt.Media.SbPlayer.WriteSamples.Audio.LatencyTiming"
+    units="microseconds" expires_after="never">
+<!-- expires-never: Needed for long-term tracking of SbPlayer latencies. -->
+
+  <owner>[email protected]</owner>
+  <owner>[email protected]</owner>
+  <summary>Timing data for writing single audio sample.</summary>
+</histogram>
+
+<histogram name="Cobalt.Media.SbPlayer.WriteSamples.Video.LatencyTiming"
+    units="microseconds" expires_after="never">
+<!-- expires-never: Needed for long-term tracking of SbPlayer latencies. -->
+
+  <owner>[email protected]</owner>
+  <owner>[email protected]</owner>
+  <summary>Timing data for writing single video sample.</summary>
+</histogram>
+
 <histogram name="Cobalt.Media.SDR.Matrix" enum="MatrixID" expires_after="never">
 <!-- expires-never: Needed for baseline Media pipeline health metric. -->