1294649 - DRM UI is confusing on Linux

Status: RESOLVED FIXED

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

Description

[Mike Hommey [:glandium]]

After bug 1289634, now on beta and aurora, this is what is visible in the UI:

- In about:addons > Plugins, Widevine Content Decryption Module is "disabled" and "Never Activate"
- In about:preferences > Content, "Play DRM content" is checked.

This is confusing, because DRM, while activated, very much depends on the status of plugins, which is not made clear. And that widevine is "Never Activate" doesn't reflect the fact that there's supposed to be a prompt.

Add to that that the "Learn more" page is written for Windows/OSX users for whom DRM *is* enabled by default, and you've scared away Linux users (without mentioning the critical bugs I'll be receiving in Debian for "WTF Debian, remove that non-free DRM crap")

Comment 1

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

I agree. I was halfway through writing a patch for this, then got distracted.

We should really have the "Play DRM Content" unchecked by default on Linux.

Comment 2

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

Attachment: Bug 1294649 - Ensure 'Play DRM Content' is unchecked by default on Linux.

The current UI for EME on Linux is confusing. We have the 'Play DRM Content'
checkbox ticked, but the CDM disabled. It would be clearer if we just had
the 'Play DRM Checkbox' unticked, and instead left the Widevine CDM enabled.
Then we won't download and install the CDM until the 'Play DRM Content'
checkbox is checked (which toggles media.eme.enabled).

This also means that the Widevine CDM won't appear in the plugins list
by default unless the 'Play DRM Checkbox' is checked.

Review commit: https://reviewboard.mozilla.org/r/71798/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/71798/

Comment 3

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

Attachment: Bug 1294649 - Don't show EME plugins in the plugin list that are disabled.

I noticed that on Linux is you have 'Play DRM content' unchecked, and then
open about:addons > plugins, and then check 'Play DRM content', that the
Adobe CDM then appears in the plugins list.

This is because on Linux the Adobe CDM is not visible by default. So we're not
creating a default value for media.gmp-eme-adobe.enabled. So then when
GMPWrapper.userDisabled() checks the pref, it's assuming it should use the
default value specified ("true"), and so we think that the Adobe CDM is not
disabled, and show it.

In onPrefEMEGlobalEnabledChanged we should also change the check so that we
uninstall the plugin if it's not active (which also checks userDisabled)
so that we uninstall the plugin if it's hidden (i.e. not enabled in the build
as the Adobe CDM is not on Linux).

Review commit: https://reviewboard.mozilla.org/r/71800/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/71800/

Comment 4

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Comment on attachment 8781359 [details]
Bug 1294649 - Ensure 'Play DRM Content' is unchecked by default on Linux.

https://reviewboard.mozilla.org/r/71798/#review69326

Comment 5

[:Gijs (he/him)]

Comment on attachment 8781360 [details]
Bug 1294649 - Don't show EME plugins in the plugin list that are disabled.

https://reviewboard.mozilla.org/r/71800/#review69408

::: toolkit/mozapps/extensions/internal/GMPProvider.jsm:369
(Diff revision 1)
> -    if (this.appDisabled) {
> +    if (!this.isActive) {
>        this.uninstallPlugin();
>      } else {
>        AddonManagerPrivate.callInstallListeners("onExternalInstall", null, this,
>                                                 null, false);
>        AddonManagerPrivate.callAddonListeners("onInstalling", this, false);
>        AddonManagerPrivate.callAddonListeners("onInstalled", this);
>        this.checkForUpdates(GMP_CHECK_DELAY);
>      }
>      if (!this.userDisabled) {
>        this._handleEnabledChanged();
>      }

This feels odd. Why is this change necessary? AFAICT this basically means that if you enable EME globally but one of the plugins is user-disabled, it will now be uninstalled. While your explanation for the Linux case where we don't actually have it as part of the install package (in which case, why is it in the list at all?) make some sense, on other OSes where we do have the Adobe CDM that doesn't sound like the right thing? Fundamentally 'uninstall' and 'disable' are / should be different things. What am I missing?

On top of that, this initial if/else block now no longer 'matches' the `!this.userDisabled` check below. Should that also be updated?

Some comments here would probably help me grok why we need to do this in addition to the pref flips that already got r+'d...

Comment 6

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

(In reply to :Gijs Kruitbosch (PTO recovery mode) from comment #5)
> Comment on attachment 8781360 [details]
> Bug 1294649 - Don't show EME plugins in the plugin list that are disabled.
> 
> https://reviewboard.mozilla.org/r/71800/#review69408
> 
> ::: toolkit/mozapps/extensions/internal/GMPProvider.jsm:369
> (Diff revision 1)
> > -    if (this.appDisabled) {
> > +    if (!this.isActive) {
> >        this.uninstallPlugin();
> >      } else {
> >        AddonManagerPrivate.callInstallListeners("onExternalInstall", null, this,
> >                                                 null, false);
> >        AddonManagerPrivate.callAddonListeners("onInstalling", this, false);
> >        AddonManagerPrivate.callAddonListeners("onInstalled", this);
> >        this.checkForUpdates(GMP_CHECK_DELAY);
> >      }
> >      if (!this.userDisabled) {
> >        this._handleEnabledChanged();
> >      }
> 
> This feels odd. Why is this change necessary? AFAICT this basically means
> that if you enable EME globally but one of the plugins is user-disabled, it
> will now be uninstalled.

That's the existing behaviour.

> While your explanation for the Linux case where we
> don't actually have it as part of the install package (in which case, why is
> it in the list at all?) make some sense, on other OSes where we do have the
> Adobe CDM that doesn't sound like the right thing? Fundamentally 'uninstall'
> and 'disable' are / should be different things. What am I missing?

Currently, all GMPs (except gmp-clearkey) are downloaded, and aren't part of the install package on all platforms.

 
> On top of that, this initial if/else block now no longer 'matches' the
> `!this.userDisabled` check below. Should that also be updated?

I will see if I can clear that up.

Comment 7

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

Comment on attachment 8781359 [details]
Bug 1294649 - Ensure 'Play DRM Content' is unchecked by default on Linux.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/71798/diff/1-2/

Comment 8

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

Comment on attachment 8781360 [details]
Bug 1294649 - Don't show EME plugins in the plugin list that are disabled.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/71800/diff/1-2/

Comment 9

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

For the record, I asked Gijs out-of-band whether he was ok for me to switch reviewers to spohl here,  and he was ok with that.

Comment 10

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

Comment on attachment 8781360 [details]
Bug 1294649 - Don't show EME plugins in the plugin list that are disabled.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/71800/diff/2-3/

Comment 11

[Stephen A Pohl [:spohl]]

Comment on attachment 8781360 [details]
Bug 1294649 - Don't show EME plugins in the plugin list that are disabled.

https://reviewboard.mozilla.org/r/71800/#review69652

Looks good to me, thanks!

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/bca6f19b9320
Ensure 'Play DRM Content' is unchecked by default on Linux. r=gerald
https://hg.mozilla.org/integration/autoland/rev/212d06d11b24
Don't show EME plugins in the plugin list that are disabled. r=spohl

Comment 13

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

I must remember to uplift.

Comment 14

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

Comment on attachment 8781359 [details]
Bug 1294649 - Ensure 'Play DRM Content' is unchecked by default on Linux.

Approval Request Comment
[Feature/regressing bug #]: Widevine Linux EME uplift
[User impact if declined]: On Linux, the DRM/EME UI will be confusing; we'll have the "Play DRM Checkbox" on the preferences pane checked and the Widevine CDM will be listed as "never activate" in the add-ons > plugins pane. This is confusing as we can't actually play DRM content without the CDM enabled. With this patch, we'll not have the "Play DRM Checkbox" checked, so it's much clearer what's going on.
[Describe test coverage new/current, TreeHerder]: We have browser chrome tests covering this I believe.
[Risks and why]: Fairly low; we're basically changing a pref and the machinery around that.
[String/UUID change made/needed]: None

Comment 15

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

Comment on attachment 8781360 [details]
Bug 1294649 - Don't show EME plugins in the plugin list that are disabled.

Approval Request Comment
[Feature/regressing bug #]: Widevine Linux EME uplift
[User impact if declined]: On Linux, the DRM/EME UI will be confusing; we'll have the "Play DRM Checkbox" on the preferences pane checked and the Widevine CDM will be listed as "never activate" in the add-ons > plugins pane. This is confusing as we can't actually play DRM content without the CDM enabled. With this patch, we'll not have the "Play DRM Checkbox" checked, so it's much clearer what's going on.
[Describe test coverage new/current, TreeHerder]: We have browser chrome tests covering this I believe.
[Risks and why]: Fairly low; we're basically changing a pref and the machinery around that.
[String/UUID change made/needed]: None

Comment 16

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/bca6f19b9320
https://hg.mozilla.org/mozilla-central/rev/212d06d11b24

Comment 17

[Ritu Kothari (:ritu) (Inactive, please n-i to RyanVM, jcristau, or pascal)]

Comment on attachment 8781360 [details]
Bug 1294649 - Don't show EME plugins in the plugin list that are disabled.

Recent regression, let's uplift to Aurora50.

Comment 18

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

https://hg.mozilla.org/releases/mozilla-aurora/rev/cf696b986483
https://hg.mozilla.org/releases/mozilla-aurora/rev/c43cb7e9ce93

Comment 19

[Liz Henry (:lizzard) (relman/hg->git project)]

Comment on attachment 8781360 [details]
Bug 1294649 - Don't show EME plugins in the plugin list that are disabled.

Nice UI improvement for video playback, let's take this for the beta 6 build.

Comment 20

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/23c836ad8064
https://hg.mozilla.org/releases/mozilla-beta/rev/b9fd9efbcd9b

Comment 21

[Gerry Chang [:gchang]]

Track 49+ as this is a regression.

Comment 22

[David Hedlund]

Firefox 57.0b4 and later is EME-free so no separate "linux-x86_64-EME-free" are distributed - https://bugzilla.mozilla.org/show_bug.cgi?id=1404048#c3

However, I just tested Firefox 59.0.2 64-bit for GNU/Linux:

- The Widevine Content Decryption Module plugin has been removed from about:addons > Plugins. -- This is good
- In about:preferences > Content, "Play DRM content" is unchecked. -- it can still be enabled so how does it make Firefox "EME-free"?

Comment 23

[:Gijs (he/him)]

(In reply to public from comment #22)
> Firefox 57.0b4 and later is EME-free so no separate "linux-x86_64-EME-free"
> are distributed - https://bugzilla.mozilla.org/show_bug.cgi?id=1404048#c3
> 
> However, I just tested Firefox 59.0.2 64-bit for GNU/Linux:
> 
> - The Widevine Content Decryption Module plugin has been removed from
> about:addons > Plugins. -- This is good
> - In about:preferences > Content, "Play DRM content" is unchecked. -- it can
> still be enabled so how does it make Firefox "EME-free"?

It's EME-free in the same way that it's Flash-free, in that the browser doesn't come with it (ie the download does not contain any proprietary EME/DRM/Flash code), but if the user explicitly chooses to have it, the browser can use it (it'll download the CDMs at some point *if* the user chooses to flip the pref). Exactly the same thing happened with the separate EME-free builds that came before it - as https://bugzilla.mozilla.org/show_bug.cgi?id=1404048#c1 notes, all it did was default a pref to false. So nothing has really changed.

Comment 24

[David Hedlund]

(In reply to :Gijs (he/him) from comment #23)
> (In reply to public from comment #22)
> > Firefox 57.0b4 and later is EME-free so no separate "linux-x86_64-EME-free"
> > are distributed - https://bugzilla.mozilla.org/show_bug.cgi?id=1404048#c3
> > 
> > However, I just tested Firefox 59.0.2 64-bit for GNU/Linux:
> > 
> > - The Widevine Content Decryption Module plugin has been removed from
> > about:addons > Plugins. -- This is good
> > - In about:preferences > Content, "Play DRM content" is unchecked. -- it can
> > still be enabled so how does it make Firefox "EME-free"?
> 
> It's EME-free in the same way that it's Flash-free, in that the browser
> doesn't come with it (ie the download does not contain any proprietary
> EME/DRM/Flash code), but if the user explicitly chooses to have it, the
> browser can use it (it'll download the CDMs at some point *if* the user
> chooses to flip the pref). Exactly the same thing happened with the separate
> EME-free builds that came before it - as
> https://bugzilla.mozilla.org/show_bug.cgi?id=1404048#c1 notes, all it did
> was default a pref to false. So nothing has really changed.

Thank you for that precise explanation.