1480484 - Add telemetry probe for measuring the amount of the blocked autoplay without audio track

Status: RESOLVED FIXED

(Core :: Audio/Video: Playback, enhancement, P2)

Description

[Alastor Wu [:alwu]]

Even the media without audio track is non-audible, we still block it in our blocking autoplay policy (so does Chrome, but Sarafi doesn't)

We want to know how many blocked autoplay is without audio track.

Comment 1

[Alastor Wu [:alwu]]

Attachment: Data review request

Comment 2

[Alastor Wu [:alwu]]

Attachment: Bug 1480484 - add telemetry scalar to measure the count for blocked media element without audio track.

It's used to count the amount that the blocked autoplay media element without audio track.

The scalar name isn't consist with other names is because of the 40 maximum limitation of the ping name.

Review commit: https://reviewboard.mozilla.org/r/261278/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/261278/

Comment 3

[Alastor Wu [:alwu]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=e5496a3b81383f8e2b69a16ca72a0e70ecf10697

Comment 4

[Chris Pearce [:cpearce (Not reading bugmail)]]

Comment on attachment 8997586 [details]
Bug 1480484 - add telemetry scalar to measure the count for blocked media element without audio track.

https://reviewboard.mozilla.org/r/261278/#review268406

::: dom/html/HTMLMediaElement.cpp:4036
(Diff revision 1)
>        (!OwnerDoc()->HasBeenUserGestureActivated() || Autoplay())) {
>      OwnerDoc()->SetDocTreeHadAudibleMedia();
>      if (AutoplayPolicy::WouldBeAllowedToPlayIfAutoplayDisabled(*this)) {
>        ScalarAdd(Telemetry::ScalarID::MEDIA_AUTOPLAY_WOULD_BE_ALLOWED_COUNT, 1);
>      } else {
> +      if (mReadyState >= HAVE_METADATA && !HasAudio()) {

A lot of sites that autoplay do something like:

let v = document.createElement("video");
v.src = url;
v.play();

So when the play() call happens, we won't have loaded metadata, and I think your telemetry would miss that? So I think we also need to check whether we should report this probe once we reach readyState HAVE_METADATA and script tried to autoplay.

Comment 5

[Alastor Wu [:alwu]]

Comment on attachment 8997586 [details]
Bug 1480484 - add telemetry scalar to measure the count for blocked media element without audio track.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/261278/diff/1-2/

Comment 6

[Chris Pearce [:cpearce (Not reading bugmail)]]

Comment on attachment 8997586 [details]
Bug 1480484 - add telemetry scalar to measure the count for blocked media element without audio track.

https://reviewboard.mozilla.org/r/261278/#review268662

Comment 7

[Chris Pearce [:cpearce (Not reading bugmail)]]

Comment on attachment 8997586 [details]
Bug 1480484 - add telemetry scalar to measure the count for blocked media element without audio track.

https://reviewboard.mozilla.org/r/261278/#review268666

::: dom/html/HTMLMediaElement.cpp:5510
(Diff revision 2)
>    NS_ASSERTION(!HasVideo() || (mMediaInfo.mVideo.mDisplay.width > 0 &&
>                                 mMediaInfo.mVideo.mDisplay.height > 0),
>                 "Video resolution must be known on 'loadedmetadata'");
>    DispatchAsyncEvent(NS_LITERAL_STRING("loadedmetadata"));
> +  // The play invocation had happened before media element loaded metadata.
> +  if (!mPaused && !HasAudio()) {

We should also check the whether volume !=0 and !muted here. We want to report the count of things that we're blocking that Safari is not.

Comment 8

[Alastor Wu [:alwu]]

Comment on attachment 8997586 [details]
Bug 1480484 - add telemetry scalar to measure the count for blocked media element without audio track.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/261278/diff/2-3/

Comment 9

[Alastor Wu [:alwu]]

Comment on attachment 8997586 [details]
Bug 1480484 - add telemetry scalar to measure the count for blocked media element without audio track.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/261278/diff/3-4/

Comment 10

[François Marier [:francois]]

Comment on attachment 8997584 [details]
Data review request

1) Is there or will there be **documentation** that describes the schema for the ultimate data set available publicly, complete and accurate?

Yes, in Scalars.yaml.

2) Is there a control mechanism that allows the user to turn the data collection on and off?

Yes, telemetry setting.

3) If the request is for permanent data collection, is there someone who will monitor the data over time?**

Not permanent.

4) Using the **[category system of data types](https://wiki.mozilla.org/Firefox/Data_Collection)** on the Mozilla wiki, what collection type of data do the requested measurements fall under?  **

Category 1.

5) Is the data collection request for default-on or default-off?

Default ON only in pre-release channels.

6) Does the instrumentation include the addition of **any *new* identifiers** (whether anonymous or otherwise; e.g., username, random IDs, etc.  See the appendix for more details)?

No.

7) Is the data collection covered by the existing Firefox privacy notice?

Yes.

8) Does there need to be a check-in in the future to determine whether to renew the data?

No, telemetry alerts are fine.

Comment 11

[François Marier [:francois]]

Comment on attachment 8997586 [details]
Bug 1480484 - add telemetry scalar to measure the count for blocked media element without audio track.

https://reviewboard.mozilla.org/r/261278/#review268864

Scalars.yaml changes look good.

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a7067dbdc7b5
add telemetry scalar to measure the count for blocked media element without audio track. r=cpearce,francois

Comment 13

[Pulsebot]

Backout by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/818b84e5278b
Backed out changeset a7067dbdc7b5 for build bustages on HTMLMediaElement.cpp. CLOSED TREE

Comment 14

[Alastor Wu [:alwu]]

Comment on attachment 8997586 [details]
Bug 1480484 - add telemetry scalar to measure the count for blocked media element without audio track.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/261278/diff/4-5/

Comment 15

[Alastor Wu [:alwu]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=5320fa158dc5affa739f8d6219b7f5de00ff1c1b

Comment 16

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/753fc72a27d5
add telemetry scalar to measure the count for blocked media element without audio track. r=cpearce,francois

Comment 17

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/753fc72a27d5