Index: tools/perf/measurements/webrtc_rendering.py |
diff --git a/tools/perf/measurements/webrtc_rendering.py b/tools/perf/measurements/webrtc_rendering.py |
new file mode 100644 |
index 0000000000000000000000000000000000000000..1dd8cf8c14dbe79a626eadc9f20034a6f7af1a7d |
--- /dev/null |
+++ b/tools/perf/measurements/webrtc_rendering.py |
@@ -0,0 +1,314 @@ |
+# 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. |
+import numpy |
+import logging |
+ |
+from telemetry.timeline import tracing_category_filter |
+from telemetry.timeline import tracing_options |
+from telemetry.timeline import model |
+from telemetry.page import page_test |
+from telemetry.value import scalar |
+from telemetry.value import list_of_scalar_values |
+from telemetry.value import list_of_string_values |
+from metrics import power |
+ |
+ |
+DISPLAY_HERTZ = 60.0 |
+# When to consider a frame frozen (in VSYNC units): |
+# meaning 1 initial frame + 5 repeats of that frame. |
+FROZEN_THRESHOLD = 6 |
+# Severity factor. |
+SEVERITY = 3 |
+ |
+ |
+class WebMediaPlayerMsRenderingStats(object): |
+ """Analyzes events of WebMediaPlayerMs type.""" |
+ |
+ def __init__(self, events): |
+ """Save relevant events.""" |
+ self.relevant_events = events |
+ |
+ def InferCadence(self): |
+ """Calculate the apparent cadence of the rendering.""" |
+ # Term 'cadence' loosely used here for lack of a better word. |
+ cadence = [] |
+ frame_persistence = 0 |
+ old_ideal_render = 0 |
+ for event in self.relevant_events: |
+ if (event.args and 'Ideal Render Instant' in event.args |
+ and event.args['Ideal Render Instant'] == old_ideal_render): |
+ frame_persistence += 1 |
+ elif event.args and 'Ideal Render Instant' in event.args: |
+ cadence.append(frame_persistence) |
+ frame_persistence = 1 |
+ old_ideal_render = event.args['Ideal Render Instant'] |
+ cadence.append(frame_persistence) |
+ cadence.pop(0) |
+ return cadence |
+ |
+ def Bucketize(self, cadence): |
+ """Create distribution for the cadence frame display values.""" |
+ # If the overall display distribution is A1:A2:..:An, |
+ # this will tell us how many times a frame |
+ # stays displayed during Ak vsync duration (i.e. Ak/DISPLAY_HERTZ) |
+ # also known as 'source to output' distribution. |
+ bucket = {} |
+ for ticks in cadence: |
+ if ticks in bucket: |
+ bucket[ticks] += 1 |
+ else: |
+ bucket[ticks] = 1 |
+ return bucket |
+ |
+ def InferFpsFromCadence(self, bucket): |
+ """Calculate the apparent FPS from cadence pattern.""" |
+ # The mean ratio is the barycenter |
+ weight = sum([bucket[ticks] for ticks in bucket]) |
qiangchen
2015/08/28 21:26:01
Possibly name this variable as num_frames.
cpaulin (no longer in chrome)
2015/09/16 22:57:04
Done.
|
+ population= sum([ticks * bucket[ticks] for ticks in bucket]) |
qiangchen
2015/08/28 21:26:01
Possibly name this variable as num_vsyncs.
cpaulin (no longer in chrome)
2015/09/16 22:57:04
Done.
|
+ mean_ratio = float(population) / weight |
+ fps = DISPLAY_HERTZ / mean_ratio |
+ return fps |
+ |
+ def InferFrozenFramesEvents(self, bucket): |
+ """Find evidence of frozen frames in distribution.""" |
+ # For simplicity we count as freezing the frames |
+ # that appear at least five times in a row |
+ # counted from 'Ideal Render Instant' perspective. |
+ frozen_frames = [] |
+ for ticks in bucket: |
+ if ticks >= FROZEN_THRESHOLD: |
+ logging.error('%s frames not updated after %s vsyncs', |
+ bucket[ticks], ticks) |
+ frozen_frames.append( |
+ {'frozen_frames' : ticks -1 , |
qiangchen
2015/08/28 21:26:01
Question: why we take ticks-1 here?
cpaulin (no longer in chrome)
2015/09/16 22:57:05
Because if you have 1 source frame and it displaye
|
+ 'occurences' : bucket[ticks]}) |
+ return frozen_frames |
+ |
+ def FrozenPenaltyWeight(self, number_frozen_frames): |
+ """Returns the weighted penalty for a number of frozen frames.""" |
+ # As mentioned earlier, we count for frozen anything above 6 vsync |
+ # display duration for the same 'Initial Render Instant'. |
+ penalty = { |
+ 0 : 0, |
+ 1 : 0, |
+ 2 : 0, |
+ 3 : 0, |
+ 4 : 0, |
+ 5 : 1, |
+ 6 : 5, |
+ 7 : 15, |
+ 8 : 25 |
+ } |
+ weight = penalty.get(number_frozen_frames, |
+ 8 * (number_frozen_frames - 4)) |
+ return weight |
+ |
+ def InferTimeStats(self): |
+ """Calculate time stamp stats for all events.""" |
+ |
+ cadence = self.InferCadence() |
+ bucket = self.Bucketize(cadence) |
+ fps = self.InferFpsFromCadence(bucket) |
+ frozen_frames = self.InferFrozenFramesEvents(bucket) |
+ # Drift time between Ideal Render Instant and Actual Render Begin. |
+ drift_time = [] |
+ old_ideal_render = 0 |
+ discrepancy = [] |
+ index = 0 |
+ for event in self.relevant_events: |
+ current_ideal_render = event.args['Ideal Render Instant'] |
+ if current_ideal_render == old_ideal_render: |
+ continue |
+ drift_time.append( |
+ event.args['Actual Render Begin'] - current_ideal_render) |
+ discrepancy.append(abs(current_ideal_render - old_ideal_render |
+ - 1e6 / DISPLAY_HERTZ * cadence[index])) |
+ old_ideal_render = current_ideal_render |
+ index += 1 |
+ discrepancy.pop(0) |
+ last_ideal_render = self.relevant_events[-1].args[ |
+ 'Ideal Render Instant'] |
+ first_ideal_render = self.relevant_events[0].args[ |
+ 'Ideal Render Instant'] |
+ rendering_length_error = 100.0 * (sum([x for x in discrepancy]) / |
+ (last_ideal_render - first_ideal_render)) |
+ # Some stats on drift time. |
+ mean_drift_time = numpy.mean(drift_time) |
+ std_dev_drift_time = numpy.std(drift_time) |
+ norm_drift_time = [abs(x - mean_drift_time) for x in drift_time] |
+ # How many times is a frame later/earlier than T=2/DISPLAY_HERTZ. |
+ # Time is in microseconds. |
+ frames_severely_out_of_sync = len( |
+ [x for x in norm_drift_time if abs(x) > 2e6 / DISPLAY_HERTZ]) |
qiangchen
2015/08/28 21:26:01
How about defining a variable say vsync_duration =
|
+ percent_badly_oos = ( |
+ 100.0 * frames_severely_out_of_sync / len(norm_drift_time)) |
+ # How many times is a frame later/earlier than 1/DISPLAY_HERTZ. |
+ frames_out_of_sync = len( |
+ [x for x in norm_drift_time if abs(x) > 1e6 / (DISPLAY_HERTZ)]) |
+ percent_out_of_sync = ( |
+ 100.0 * frames_out_of_sync / len(norm_drift_time)) |
+ |
+ frames_oos_only_once = frames_out_of_sync - frames_severely_out_of_sync |
+ # For safety I don't use population = len(self.relevant_events) just |
+ # in case other events are added later. |
+ population = sum([n * bucket[n] for n in bucket]) |
qiangchen
2015/08/28 21:26:01
ditto
|
+ # Calculate smoothness metric. |
+ # From the formula, we can see that smoothness score can be negative. |
+ smoothness_score = 100.0 - 100.0*(frames_oos_only_once + |
+ SEVERITY * frames_severely_out_of_sync) / len(norm_drift_time) |
+ # Calculate freezing metric. |
+ # Freezing metric can be negative if things are really bad. |
+ freezing_score = 100.0 |
+ for frozen_report in frozen_frames: |
+ weight = self.FrozenPenaltyWeight(frozen_report['frozen_frames']) |
+ freezing_score -= ( |
+ 100.0 * frozen_report['occurences'] / population * weight) |
+ |
+ stats = { |
+ 'drift_time': drift_time, |
+ 'mean_drift_time' : mean_drift_time, |
+ 'std_dev_drift_time' : std_dev_drift_time, |
+ 'percent_badly_out_of_sync' : percent_badly_oos, |
+ 'percent_out_of_sync' : percent_out_of_sync, |
+ 'smoothness_score' : smoothness_score, |
+ 'freezing_score' : freezing_score, |
+ 'rendering_length_error' : rendering_length_error, |
+ 'fps' : fps, |
+ 'bucket' : bucket} |
+ return stats |
+ |
+ |
+class WebRTCRendering(page_test.PageTest): |
nednguyen
2015/09/02 16:26:46
Please don't add another page_test & use TimelineB
phoglund_chromium
2015/09/04 09:16:24
Right, and so most of this code should be a Metric
|
+ """Gathers WebRTC video rendering-related metrics on a page set.""" |
+ |
+ def __init__(self): |
+ super(WebRTCRendering, self).__init__() |
+ self._power_metric = None |
+ self._webrtc_rendering_metric = None |
+ |
+ def WillStartBrowser(self, platform): |
+ self._power_metric = power.PowerMetric(platform) |
+ |
+ def WillNavigateToPage(self, page, tab): |
+ self._power_metric.Start(page, tab) |
+ |
+ options = tracing_options.TracingOptions() |
+ options.enable_chrome_trace = True |
+ # FIXME: Remove the timeline category when impl-side painting is on |
+ # everywhere. |
+ category_filter = tracing_category_filter.TracingCategoryFilter('cc') |
+ tab.browser.platform.tracing_controller.Start(options, category_filter) |
+ |
+ def CustomizeBrowserOptions(self, options): |
+ #options.AppendExtraBrowserArgs('--use-fake-device-for-media-stream') |
+ options.AppendExtraBrowserArgs('--use-fake-ui-for-media-stream') |
+ power.PowerMetric.CustomizeBrowserOptions(options) |
+ |
+ def StopBrowserAfterPage(self, browser, page): |
+ # Restart the browser after the last page in the pageset. |
+ return True |
+ |
+ def ValidateAndMeasurePage(self, page, tab, results): |
+ timeline_data = tab.browser.platform.tracing_controller.Stop() |
+ timeline_model = model.TimelineModel(timeline_data) |
+ self._power_metric.Stop(page, tab) |
+ self._power_metric.AddResults(tab, results) |
+ rendering_events = timeline_model.GetAllEventsOfName( |
+ 'WebMediaPlayerMS::UpdateCurrentFrame') |
+ if not rendering_events: |
+ rendering_events = [{'args':{'Unkown':'Unknown'}}] |
+ # TBD what to do next when no events exist? |
+ event_parser = WebMediaPlayerMsRenderingStats(rendering_events) |
+ rendering_stats = event_parser.InferTimeStats() |
+ logging.info ("rendering stats : %s", rendering_stats) |
+ results.AddValue(list_of_scalar_values.ListOfScalarValues( |
+ results.current_page, |
+ 'WebRtcRendering_drift_time', |
+ 'usec', |
+ rendering_stats['drift_time'], |
+ important=True, |
+ description='Drift time for a rendered frame')) |
+ |
+ results.AddValue(scalar.ScalarValue( |
+ results.current_page, |
+ 'WebRTCRendering_mean_drift_time', |
+ 'usec', |
+ rendering_stats['mean_drift_time'], |
+ important=True, |
+ description='Mean drift time for frames')) |
+ |
+ results.AddValue(scalar.ScalarValue( |
+ results.current_page, |
+ 'WebRTCRendering_std_dev_drift_time', |
+ 'usec', |
+ rendering_stats['std_dev_drift_time'], |
+ important=True, |
+ description='Standard deviation of drift time for frames')) |
+ |
+ 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')) |
+ |
+ 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')) |
+ |
+ # make the output distribution a list since |
+ # no facilities for dict values exist (yet) |
+ bucket_list = [] |
+ for key, value in rendering_stats['bucket'].iteritems(): |
+ temp = "%s:%s" % (key,value) |
+ bucket_list.append(temp) |
+ results.AddValue(list_of_string_values.ListOfStringValues( |
+ results.current_page, |
+ 'WebRtcRendering_bucket', |
+ 'frames:occurences', |
+ bucket_list, |
+ important=True, |
+ description='Output distribution of frames')) |
+ |
+ results.AddValue(scalar.ScalarValue( |
+ results.current_page, |
+ 'WebRTCRendering_fps', |
+ 'FPS', |
+ rendering_stats['fps'], |
+ important=True, |
+ description='Calculated Frame Rate of video rendering')) |
+ |
+ results.AddValue(scalar.ScalarValue( |
+ results.current_page, |
+ 'WebRTCRendering_smoothness_score', |
+ '%', |
+ rendering_stats['smoothness_score'], |
+ important=True, |
+ description='Smoothness score of rendering')) |
+ |
+ results.AddValue(scalar.ScalarValue( |
+ results.current_page, |
+ 'WebRTCRendering_freezing_score', |
+ '%', |
+ rendering_stats['freezing_score'], |
+ important=True, |
+ description='Freezing score of rendering')) |
+ |
+ results.AddValue(scalar.ScalarValue( |
+ results.current_page, |
+ 'WebRTCRendering_rendering_length_error', |
+ '%', |
+ rendering_stats['rendering_length_error'], |
+ important=True, |
+ description='Rendering length error rate')) |
+ |
+ def CleanUpAfterPage(self, page, tab): |
+ tracing_controller = tab.browser.platform.tracing_controller |
+ if tracing_controller.is_tracing_running: |
+ tracing_controller.Stop() |