Chromium Code Reviews Chromium Code Reviews
Issue 2996233004:
Port a media metric to TBMv2 (Closed)
| Index: tracing/tracing/metrics/media_metric.html |
| diff --git a/tracing/tracing/metrics/media_metric.html b/tracing/tracing/metrics/media_metric.html |
| new file mode 100644 |
| index 0000000000000000000000000000000000000000..53d13310abf7f3030675ed94257e8e2eda071e42 |
| --- /dev/null |
| +++ b/tracing/tracing/metrics/media_metric.html |
| @@ -0,0 +1,75 @@ |
| +<!DOCTYPE html> |
| +<!-- |
| +Copyright 2017 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. |
| +--> |
| + |
| +<!-- |
| +media_metrics uses Chrome trace events to calculate metrics about video |
| +and audio playback. It is meant to be used for pages with a <video> or |
| +<audio> element. It is used by videostack-eng@google.com team for |
| +regression testing. |
| + |
| +This metric currently supports the following measurement: |
| +* time_to_play calculates how long after a video is requested to |
| + start playing before the video actually starts. If time_to_play |
| + regresses, then users will click to play videos and then have |
| + to wait longer before the videos start actually playing. |
| + |
| +More measurements are expected to be added in the near future, such as: |
| +* buffering_time |
| +* seek_time |
| +* dropped_frame_count |
| + |
| +Please inform crouleau@chromium.org and johnchen@chromium.org about |
| +changes to this file. |
| +--> |
| + |
| +<link rel="import" href="/tracing/metrics/metric_registry.html"> |
| +<link rel="import" href="/tracing/model/helpers/chrome_model_helper.html"> |
| +<link rel="import" href="/tracing/value/histogram.html"> |
| + |
| +<script> |
| +'use strict'; |
| + |
| +tr.exportTo('tr.metrics', function() { |
| + function mediaMetric(histograms, model) { |
| + let playStart; |
| + let timeToPlay; |
| + |
| + const chromeHelper = model.getOrCreateHelper( |
| + tr.model.helpers.ChromeModelHelper); |
| + if (chromeHelper === undefined) return; |
| + for (const rendererHelper of Object.values(chromeHelper.rendererHelpers)) { |
| + for (const event of rendererHelper.process.getDescendantEvents()) { |
|
benjhayden
2017/08/29 23:17:25
Thanks, this is good, keep going.
Which thread[s]
johnchen
2017/08/30 01:39:19
The code now looks for the events on specific thre
|
| + if (event.title === 'WebMediaPlayerImpl::DoLoad') { |
| + if (playStart === undefined) { |
| + playStart = event.start; |
| + } |
| + } else if (event.title === 'VideoRendererImpl::Render' || |
| + event.title === 'AudioRendererImpl::Render') { |
| + if (playStart !== undefined && timeToPlay === undefined) { |
| + timeToPlay = event.start - playStart; |
| + break; |
|
benjhayden
2017/08/29 23:17:25
We try to make metrics as general as possible in o
johnchen
2017/08/30 01:39:19
The Render events are raised for each video frame.
|
| + } |
| + } |
| + } |
| + if (timeToPlay !== undefined) { |
| + break; |
| + } |
| + } |
| + |
| + if (timeToPlay !== undefined) { |
| + histograms.createHistogram('time_to_play', |
| + tr.b.Unit.byName.timeDurationInMs_smallerIsBetter, timeToPlay); |
| + } |
| + } |
| + |
| + tr.metrics.MetricRegistry.register(mediaMetric); |
| + |
| + return { |
| + mediaMetric, |
| + }; |
| +}); |
| +</script> |
