| 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..3e86e7d26a9025fd0ad49bd7c485c5bdc9a1e564
|
| --- /dev/null
|
| +++ b/tracing/tracing/metrics/media_metric.html
|
| @@ -0,0 +1,115 @@
|
| +<!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_video_play calculates how long after a video is requested to
|
| + start playing before the video actually starts. If time_to_video_play
|
| + regresses, then users will click to play videos and then have
|
| + to wait longer before the videos start actually playing.
|
| +* time_to_audio_play is similar to time_to_video_play, but measures the
|
| + time delay before audio starts 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 timeToAudioPlay;
|
| + let timeToVideoPlay;
|
| +
|
| + const chromeHelper = model.getOrCreateHelper(
|
| + tr.model.helpers.ChromeModelHelper);
|
| + if (chromeHelper === undefined) return;
|
| +
|
| + for (const rendererHelper of Object.values(chromeHelper.rendererHelpers)) {
|
| + // Find the threads we're interested in, and if a needed thread
|
| + // is missing, no need to look further in this process.
|
| + const mainThread = rendererHelper.mainThread;
|
| + if (mainThread === undefined) continue;
|
| +
|
| + const compositorThread = rendererHelper.compositorThread;
|
| + const audioThread =
|
| + rendererHelper.process.findAtMostOneThreadNamed('AudioOutputDevice');
|
| + if (compositorThread === undefined && audioThread === undefined) continue;
|
| +
|
| + // Look for the media player DoLoad event on main thread.
|
| + for (const event of mainThread.getDescendantEvents()) {
|
| + if (event.title === 'WebMediaPlayerImpl::DoLoad') {
|
| + // TODO(johnchen@chromium.org): Support multiple audio/video
|
| + // elements per page. Currently, we only support a single
|
| + // audio or video element, so we can store the start time in
|
| + // a simple variable, and exit the loop.
|
| + if (playStart !== undefined) {
|
| + throw new Error(
|
| + 'Loading multiple audio/video elements not yet supported');
|
| + }
|
| + playStart = event.start;
|
| + break;
|
| + }
|
| + }
|
| + if (playStart === undefined) continue;
|
| +
|
| + // Look for video render event.
|
| + if (compositorThread !== undefined) {
|
| + for (const event of compositorThread.getDescendantEvents()) {
|
| + if (event.title === 'VideoRendererImpl::Render') {
|
| + timeToVideoPlay = event.start - playStart;
|
| + break;
|
| + }
|
| + }
|
| + }
|
| +
|
| + // Look for audio render event.
|
| + if (audioThread !== undefined) {
|
| + for (const event of audioThread.getDescendantEvents()) {
|
| + if (event.title === 'AudioRendererImpl::Render') {
|
| + timeToAudioPlay = event.start - playStart;
|
| + break;
|
| + }
|
| + }
|
| + }
|
| + if (timeToVideoPlay !== undefined) break;
|
| + if (timeToAudioPlay !== undefined) break;
|
| + }
|
| +
|
| + if (timeToVideoPlay !== undefined) {
|
| + histograms.createHistogram('time_to_video_play',
|
| + tr.b.Unit.byName.timeDurationInMs_smallerIsBetter, timeToVideoPlay);
|
| + }
|
| + if (timeToAudioPlay !== undefined) {
|
| + histograms.createHistogram('time_to_audio_play',
|
| + tr.b.Unit.byName.timeDurationInMs_smallerIsBetter, timeToAudioPlay);
|
| + }
|
| + }
|
| +
|
| + tr.metrics.MetricRegistry.register(mediaMetric);
|
| +
|
| + return {
|
| + mediaMetric,
|
| + };
|
| +});
|
| +</script>
|
|
|
Chromium Code Reviews
Issue 2996233004:
Port a media metric to TBMv2 (Closed)
