Telemetry Test for WebRTC Rendering.

tools/telemetry/telemetry/web_perf/metrics/webrtc_rendering_timeline.py

+# 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.
+
+from telemetry.value import list_of_scalar_values
+from telemetry.value import scalar
+from telemetry.value import improvement_direction
+from telemetry.web_perf.metrics import timeline_based_metric
+from telemetry.web_perf.metrics import webrtc_rendering_stats as stats_helper
+
+WEB_MEDIA_PLAYER_MS_EVENT = 'WebMediaPlayerMS::UpdateCurrentFrame'
+
+
+class WebRtcRenderingTimelineMetric(timeline_based_metric.TimelineBasedMetric):
+  """WebrtcRenderingTimelineMetric calculates metric for WebMediaPlayerMS.
+
+  The following metrics are added to the results:
+    WebRTCRendering_drift_time us
+    WebRTCRendering_percent_badly_out_of_sync %
+    WebRTCRendering_percent_out_of_sync %
+    WebRTCRendering_fps FPS
+    WebRTCRendering_smoothness_score %
+    WebRTCRendering_freezing_score %
+    WebRTCRendering_rendering_length_error %
+  """
+
+  def __init__(self):
+    super(WebRtcRenderingTimelineMetric, self).__init__()
+
+  @staticmethod
+  def IsMediaPlayerMSEvent(event):
+    """Verify that the event is a webmediaplayerMS event."""
+    return event.name == WEB_MEDIA_PLAYER_MS_EVENT
+
+  def AddResults(self, model, renderer_thread, interactions, results):
+    """Adding metrics to the results."""
+    assert interactions
+    found_events = []
+    for event in renderer_thread.parent.IterAllEvents(
+        event_predicate=self.IsMediaPlayerMSEvent):
+      if timeline_based_metric.IsEventInInteractions(event, interactions):
+        found_events.append(event)
+    stats_parser = stats_helper.WebMediaPlayerMsRenderingStats(found_events)
+    rendering_stats = stats_parser.GetTimeStats()
+    none_reason = None
+    if not rendering_stats:
+      # Create a TimeStats object whose members have None values.
+      rendering_stats = stats_helper.TimeStats()
+      none_reason = 'No WebMediaPlayerMS::UpdateCurrentFrame event found'
+    results.AddValue(list_of_scalar_values.ListOfScalarValues(
+        results.current_page,
+        'WebRTCRendering_drift_time',
+        'us',
+        rendering_stats.drift_time,
+        important=True,
+        description='Drift time for a rendered frame',
+        improvement_direction=improvement_direction.DOWN,
+        none_value_reason=none_reason))
+
+    results.AddValue(scalar.ScalarValue(
+        results.current_page,
+        'WebRTCRendering_percent_badly_out_of_sync',
+        '%',
+        rendering_stats.percent_badly_out_of_sync,
+        important=True,
+        description='Percentage of frame which drifted more than 2 VSYNC',
+        improvement_direction=improvement_direction.DOWN,
+        none_value_reason=none_reason))
+
+    results.AddValue(scalar.ScalarValue(
+        results.current_page,
+        'WebRTCRendering_percent_out_of_sync',
+        '%',
+        rendering_stats.percent_out_of_sync,
+        important=True,
+        description='Percentage of frame which drifted more than 1 VSYNC',
+        improvement_direction=improvement_direction.DOWN,
+        none_value_reason=none_reason))
+
+    # I removed the frame distribution list from stats as it is not a metric,
+    # rather it is the underlying data. Also there is no sense of improvement
+    # direction for frame distribution.
+
+    results.AddValue(scalar.ScalarValue(
+        results.current_page,
+        'WebRTCRendering_fps',
+        'fps',
+        rendering_stats.fps,
+        important=True,
+        description='Calculated Frame Rate of video rendering',
+        improvement_direction=improvement_direction.UP,
+        none_value_reason=none_reason))
+
+    results.AddValue(scalar.ScalarValue(
+        results.current_page,
+        'WebRTCRendering_smoothness_score',
+        '%',
+        rendering_stats.smoothness_score,
+        important=True,
+        description='Smoothness score of rendering',
+        improvement_direction=improvement_direction.UP,
+        none_value_reason=none_reason))
+
+    results.AddValue(scalar.ScalarValue(
+        results.current_page,
+        'WebRTCRendering_freezing_score',
+        '%',
+        rendering_stats.freezing_score,
+        important=True,
+        description='Freezing score of rendering',
+        improvement_direction=improvement_direction.UP,
+        none_value_reason=none_reason))
+
+    results.AddValue(scalar.ScalarValue(
+        results.current_page,
+        'WebRTCRendering_rendering_length_error',
+        '%',
+        rendering_stats.rendering_length_error,
+        important=True,
+        description='Rendering length error rate',
+        improvement_direction=improvement_direction.DOWN,
+        none_value_reason=none_reason))