1457661 - Audio canplaythrough event does not fire when loaded from URL.createObjectURL source created from a Blob created from an arraybuffer loaded via XMLHttpRequest

Status: VERIFIED FIXED

(Core :: Audio/Video: Playback, defect)

Description

[Emma Maassen]

Attachment: FirefoxCanPlayThroughTest.zip

User Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:59.0) Gecko/20100101 Firefox/59.0
Build ID: 20180323154952

Steps to reproduce:

I load an OGG file via XMLHttpRequest with responseType arraybuffer. I then create a Blob using that arraybuffer with type audio/ogg, and pass that to URL.createObjectURL.

After this I create an audio element, add the canplaythrough even listener, set preload to auto, set src to the url created via URL.createObjectURL, and call the load function.

Can confirm this used to work as late as December 2017. Using responseType blob instead of arraybuffer seems to have the expected result. Code that minimally reproduces the issue has been attached as a zip.


Actual results:

The canplaythrough event never fires and readyState is stuck at 3 (HAVE_FUTURE_DATA).


Expected results:

The canplaythrough event should fire and readyState should be set to 4 (HAVE_ENOUGH_DATA). This used to be the case as late as December 2017.

Comment 1

[Cosmin Muntean [:cmuntean], Ecosystem QA]

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0
Firefox: 61.0a1, Build ID: 20180501220047

I have managed to reproduce this issue on latest Firefox (59.0.3) release and latest Nightly (61.0a1) build. After I have opened the attached test case, nothing happened and the "3" message was displayed in browser console.
However, I have also tested this on an older Nightly build (build from 2017-12-01) and the issue is not reproducible. After I have opened the provided test case, a "can-play-through" dialog appeared and the "4" message was displayed in browser console after I clicked the "OK" button.

Considering this, I have found the regression window using the mozregression tools. Here are the results:
Last good revision: 772fef647fd7750f8c87dfd4f55bbd85046a555a
First bad revision: 821560cd716d50fbb0c49d0170bd351255e55bc3
Pushlog: https://goo.gl/VYxvVL

Looks like bug 1423465 introduced this issue.
Wang, can you please take a look at this?

Comment 2

[Jean-Yves Avenard [:jya]]

:jw_wang unfortunately no longer works at mozilla.

Comment 4

[Jean-Yves Avenard [:jya]]

Bug was introduced in P5 of bug 1423465
https://hg.mozilla.org/integration/autoland/rev/a493885e5a0d

Prior P5, ChannelMediaDecoder::CanPayThroughImpl() would calculate the playback rate synchronously when called.

However, following P5, mCanPlayThrough is cached and only calculated through ChannelMediaDecoder::DownloadProgressed()

This method is never called as the resource has completed loading when we use an arraybuffer

Comment 5

[Jean-Yves Avenard [:jya]]

Attachment: Bug 1457661 - P1. Add mochitest.

Review commit: https://reviewboard.mozilla.org/r/247328/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/247328/

Comment 6

[Jean-Yves Avenard [:jya]]

Attachment: Bug 1457661 - P2. Ensure we call NotifyDataEnded for local resource once size is known.

A call to NotifyDataEnded is required even if the size was known when the resource was created. This ensures that the readyState is properly updated and that playback can immediately as no more data can be added once first loaded.

Review commit: https://reviewboard.mozilla.org/r/247330/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/247330/

Comment 7

[Jean-Yves Avenard [:jya]]

Could you please try with this build ?

https://queue.taskcluster.net/v1/task/NnuNIIaPQf-hADmEAJ4-ig/runs/0/artifacts/public/build/target.zip

simply unzip and run the firefox.exe 

thank you

Comment 8

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Comment on attachment 8981248 [details]
Bug 1457661 - P1. Add mochitest.

https://reviewboard.mozilla.org/r/247328/#review253568

::: dom/media/test/test_arraybuffer.html:4
(Diff revision 1)
> +<!DOCTYPE HTML>
> +<html>
> +<!--
> +https://bugzilla.mozilla.org/show_bug.cgi?id=1462967

Should the test reference bug 1457661 since we're landing it against that bug and 1462967 is marked as a dupe?

::: dom/media/test/test_arraybuffer.html:7
(Diff revision 1)
> +<html>
> +<!--
> +https://bugzilla.mozilla.org/show_bug.cgi?id=1462967
> +-->
> +<head>
> +  <title>Test for Bug 462957</title>

Missing first digit of bug

::: dom/media/test/test_arraybuffer.html:69
(Diff revision 1)
> +    });
> +    const blob = new Blob([arr], {type:test.type});
> +    const blobUrl = URL.createObjectURL(blob);
> +
> +    document.body.appendChild(v);
> +    v.preload = "auto"

Missing semicolon

Comment 9

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Comment on attachment 8981249 [details]
Bug 1457661 - P2. Ensure we call NotifyDataEnded for local resource once size is known.

https://reviewboard.mozilla.org/r/247330/#review253598

Comment 10

[Jean-Yves Avenard [:jya]]

Comment on attachment 8981248 [details]
Bug 1457661 - P1. Add mochitest.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/247328/diff/1-2/

Comment 11

[Jean-Yves Avenard [:jya]]

Comment on attachment 8981249 [details]
Bug 1457661 - P2. Ensure we call NotifyDataEnded for local resource once size is known.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/247330/diff/1-2/

Comment 12

[Jean-Yves Avenard [:jya]]

Comment on attachment 8981248 [details]
Bug 1457661 - P1. Add mochitest.

https://reviewboard.mozilla.org/r/247328/#review253568

> Should the test reference bug 1457661 since we're landing it against that bug and 1462967 is marked as a dupe?

oops of course.

> Missing semicolon

thanks for the reviews

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8569fdbf5a12
P1. Add mochitest. r=bryce
https://hg.mozilla.org/integration/autoland/rev/27562071aaaa
P2. Ensure we call NotifyDataEnded for local resource once size is known. r=bryce

Comment 14

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/8569fdbf5a12
https://hg.mozilla.org/mozilla-central/rev/27562071aaaa

Comment 15

[Emma Maassen]

(In reply to Jean-Yves Avenard [:jya] from comment #7)
> Could you please try with this build ?
> 
> https://queue.taskcluster.net/v1/task/NnuNIIaPQf-hADmEAJ4-ig/runs/0/
> artifacts/public/build/target.zip
> 
> simply unzip and run the firefox.exe 
> 
> thank you

This works as expected. Thanks for the fix!

Comment 16

[Ryan VanderMeulen [:RyanVM]]

Please request Beta approval on this when you feel that it has had sufficient bake time.

Comment 17

[Jean-Yves Avenard [:jya]]

Comment on attachment 8981248 [details]
Bug 1457661 - P1. Add mochitest.

Approval Request Comment
[Feature/Bug causing the regression]: bug 1423465
[User impact if declined]: some content will no longer autoplay, now will the proper events be fired
[Is this code covered by automated tests?]: yes, new tests added.
[Has the fix been verified in Nightly?]: yes
[Needs manual test from QE? If yes, steps to reproduce]:  none
[List of other uplifts needed for the feature/fix]: all patches (one are the tests)
[Is the change risky?]: no.
[Why is the change risky/not risky?]: we force dispatching the required event. Even before the regression caused by bug 1423465, the bug was there, just hidden.
[String changes made/needed]:

Comment 18

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 8981248 [details]
Bug 1457661 - P1. Add mochitest.

Fixes broken autoplay under some circumstances. Thanks for writing a new test for this! Approved for 61.0b11.

Comment 19

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/8fefcb80fa92
https://hg.mozilla.org/releases/mozilla-beta/rev/8721ccdef784

Comment 20

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 8981248 [details]
Bug 1457661 - P1. Add mochitest.

This has baked for awhile on Nightly and Beta without any known issues. Approved for ESR 60.1 as well.

Comment 21

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-esr60/rev/f3f1173a2813
https://hg.mozilla.org/releases/mozilla-esr60/rev/d172fac7c7d9