I'm pretty sure you do need WideVine for Amazon Prime.

Normally Firefox can download and install the Widevine plugin in the background when a site requires it. (Watch DRM content on Firefox)

Some users have problems with automatic installation and need to download manually. Let's see whether these old instructions (adapted for the new design of about:config) work for you.

(1) Download a recent version for your platform

If you look at this source file -- https://dxr.mozilla.org/mozilla-release/source/toolkit/content/gmp-sources/widevinecdm.json -- there seem to be multiple choices for Linux. I don't know which is most appropriate for your processor.

If you can't download, the redirect might be blocked. Check whether any of your add-ons or any external software block redirects. You also could test downloading in another browser.

(2) Extract/install the contents of the ZIP archive into a folder in your profile

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" Help > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter/Return

In the first table on the page, on the Profile Folder row, click the button labeled "Open Folder" or "Open Directory" This should launch a new window listing various files and folders in your system's file browser.

If you see a folder named gmp-widevinecdm, double-click into that folder.

If that folder does not exist: create a new folder with that name and then double-click into it.

Select and copy the current version as the next folder name: 4.10.1582.2

Create a new folder with that name and then double-click into it. So now you are here:

[profile.folder]\gmp-widevinecdm\4.10.1582.2

Finally you can drop the contents of the ZIP archive here:

• LICENSE.txt
• manifest.json
• libwidevinecdm.so
• widevinecdm.dll
• widevinecdm.dll.lib
• widevinecdm.dll.sig

(3) Check preferences

Presumably Firefox will discover that new Widevine folder at your next startup, but possibly you would also need to create some settings.

Here are custom settings I see:

(A) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(B) In the search box in the page, type or paste widevinecdm and pause while the list is filtered. You should see at least these two:

• media.gmp-widevinecdm.enabled => true
• media.gmp-widevinecdm.visible => true

Double-click false to flip to true if needed

(C) If you do not see a media.gmp-widevinecdm.abi preference, paste that into the search box. Firefox should show it on a bar with you choice of preference type -- select String -- and + button to add it. The value should match the platform string of the plugin you installed, such as Linux_x86_64-gcc3 -- you can copy paste that from the source code page.

(D) If you filter using wide again, if you do not see a media.gmp-widevinecdm.version preference, paste that into the search box. Firefox should show it on a bar with you choice of preference type -- select String -- and + button to add it. The value should match the version of the plugin you installed, which is currently 4.10.1582.2 (as of this writing).

Does that help?

Try the Firefox version from the official Mozilla server if you currently use a version from the repositories of your Linux distribution.

• https://www.mozilla.org/en-US/firefox/all/#product-desktop-release

Thanks for the suggestions.

I opened the .json file and saw the following choices for Linux.

“Linux_x86_64-gcc3" "Linux_x86_64-gcc3-asan" "Linux_x86-gcc3"

Unfortunately they are all for x86. None for ARM.

There is one choice for ARM but not for Linux.

"WINNT_aarch64-msvc-aarch64"

I assume that means there is no way to run Widevine on an ARM platform running Linux.

You can do a Google search to get some suggestions for using Widevine on an ARM platform.

• https://www.google.com/search?sa=N&num=100&q=Widevine%20ARM