I'm against merging this as is, as it changes the de-facot default, even though the default is broken, as you've pointed out.

Although I don't really know what the best solution would be, either. We could always go the "a documented bug isn't a bug" route and just add something to the release notes saying "Firefox DRM was mistakenly enabled by default, because the option to disable it, which was and is set to false, was broken. That option was fixed and now it is actually disabled by default. To re-enable it, put this (overlay, whatever, something, idk) into your configuration."

I had a look through the Firefox source code, and the only change this option makes is whether the following options are enabled by default:

browser.eme.ui.enabled
media.gmp-widevinecdm.visible
media.gmp-widevinecdm.enabled

So it doesn’t actually leave out support for anything. I assume this means that if a user had previously enabled DRM, updating Firefox to one built with drmSupport set to false wouldn’t suddenly disable it for them. On the other hand, it would also remove the UI that would allow them to turn it off.

I wonder if there might be a middle ground here — what if we make drmSupport mean “does Firefox prompt the user to install Widevine?”. We could then leave the checkbox in about:preferences enabled, but disable the prompt when a website tries to use DRM. That way, we wouldn’t be artificially complicating enabling DRM for a user that wants to succumb to it, but Firefox wouldn’t be going out of its way to tell them to do it either.

I assume this means that if a user had previously enabled DRM, updating Firefox to one built with drmSupport set to false wouldn’t suddenly disable it for them. On the other hand, it would also remove the UI that would allow them to turn it off.

Can you verify that assumption? If not, I can maybe look into how Firefox actually behaves when this changes, soonish.

I wonder if there might be a middle ground here — what if we make drmSupport mean “does Firefox prompt the user to install Widevine?”. We could then leave the checkbox in about:preferences enabled, but disable the prompt when a website tries to use DRM. That way, we wouldn’t be artificially complicating enabling DRM for a user that wants to succumb to it, but Firefox wouldn’t be going out of its way to tell them to do it either.

That sounds like it might be a reasonable option, yes. How would we implement that?

Also, maybe some of the people maintaining Firefox now (that's @mweinelt and @lovesegfault) have some input on this.

I'm fine with changing the default behavior, but not with breaking people's setups. In other words, if this change means future users need to take an extra step to enable DRM, that's okay IMO. If, on the other hand, it meant people currently using FF with DRM (myself) have to go do something to get it to work, I'm less receptive to it.

From the discussion here, it seems to be the former, as it only changes some default configs, which is perfectly fine with me.

Before merging, ideally, someone would test:

• If you had DRM enabled / working, does it still work?
• Can you enable / use DRM after this change without having to recompile FF?

Finally, we have to be careful changing FF defaults because of the copyright issues. If we stray from what Mozilla deems acceptable defaults we have to disable all the FF branding and so on. I have no idea how to check this though. In the past, for Thunderbird, I just asked on MozIRC until I got someone to say it was alright. That IRC is gone now, but maybe Matrix might be the place to ask?

I marked this as stale due to inactivity. → More info

I consider this a bug in our build and I'm fine with merging this, but I do see the point that we should point out via release notes that this bug existed, was squashed and how to reenable DRM if one feels the need to.

was squashed and how to reenable DRM if one feels the need to.

Most people don't feel like but they are required to watch something. If you need to recompile firefox just to watch some videos you already paid for and could in the past is a terrible user experience.
Either we compile two variants of firefox or we just remove the option if it didn't work before. If you don't want the DRM stuff don't click yes when firefox prompts you to download it.

If you want DRM you can use firefox-bin for all I care.

If you want DRM you can use firefox-bin for all I care.

Thats great to know and I need to remember that. Do we have any knowledge what most people are using right now? If a lot of people need to switch to firefox-bin we should think about something else. Watching Netflix or Amazon Prime is something a lot of are doing.

I just verified what Alyssa said in #109133 (comment). I also checked browser/app/profile/firefox.js in the mozilla-central repository which contains the following logic:

• Enabling browser.eme.ui.enabled is what shows you the DRM nag bar.

#if defined(MOZ_WIDEVINE_EME)
  pref("browser.eme.ui.enabled", true);
#else
  pref("browser.eme.ui.enabled", false);
#endif

The nagbar itself enables browser.eme.enabled.

• For widevine usage on Netflix creating the following settings was sufficient:

#ifdef MOZ_WIDEVINE_EME
  pref("media.gmp-widevinecdm.visible", true);
  pref("media.gmp-widevinecdm.enabled", true);
#endif

I think we can write a sufficiently clear release notes entry from these infos and I might do it if @alyssais isn't interested in this change anymore.

If you had DRM enabled / working, does it still work?

It gets disabled and needs to be manually reenabled.

Can you enable / use DRM after this change without having to recompile FF?

Yes. Setting

  pref("media.gmp-widevinecdm.visible", true);
  pref("media.gmp-widevinecdm.enabled", true);

via about:config.

Yes. Setting

  pref("media.gmp-widevinecdm.visible", true);
  pref("media.gmp-widevinecdm.enabled", true);

via about:config.

The question is, how trivial would it be for an average user to come up with that - what kind of web search will they perform and how likely they long will it take them to find the issue. I did a quick search of "firefox no drm" and I haven't found a website mentioning these config options, hence I downvote 👎 the change in it's current form.

Taking the change here as a start, I think we also need to enable drmSupport by default, with a proper comment explaining that one can disable the download of the blobs with a proper change in about:config.

I originally posted these comments in https://matrix.to/#/#mozilla:nixos.org:

We could then leave the checkbox in about:preferences enabled, but disable the prompt when a website tries to use DRM.

This option, to me, seems like a not great option for us to apply ourselves, since it sort of silently breaks stuff in surprising ways for someone who doesn't know they have drm disabled.

From the perspective of principles it doesn't feel like a significantly complicated issue: setting drmSupport to true doesn't appear to actually do anything that harms the user except for defers the "okay but actually do you want to download the stuff?" choice to run-time. To me, this feels like a fairly respectful way to give the user the choice, and I don't think it warrants disabling that prompt in our default build.

Closed via #166078