1506579 - Use Widevine for decoding H.264 / AAC videos without DRM

Status: UNCONFIRMED

(Core :: Audio/Video: Playback, defect, P5)

Description

[Mateusz Jończyk]

User Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:63.0) Gecko/20100101 Firefox/63.0

Steps to reproduce:

I am using Firefox on Ubuntu 32-bit - a binary downloaded from https://www.mozilla.org/ (not a version obtained from my distribution).

1. In about:config, I set "media.ffmpeg.enabled=false". This would be equivalent to using a distribution that does not ship a H.264/AAC decoder by default (such as Fedora or RedHat / CentOS).
2. I made sure DRM is enabled in about:preferences.
3. I opened https://shaka-player-demo.appspot.com/demo/ and played some videos encrypted with Widevine in order for Firefox to install the Widevine plugin.
4. I opened about:addons to ensure that Widevine is installed.
5. I went to a site that allows to check which media decoders one's browser supports, such as 
    http://demo.nimius.net/video_test/
    https://tekeye.uk/html/html5-video-test-page


Actual results:

I was unable to play H.264/AAC encoded videos on these test sites.


Expected results:

Firefox would use the Widevine CDM to decode H.264/AAC videos.

I try to obey the law and therefore try not to use patent-infringing codecs. I know that to obtain legal H.264/AAC decoders I could currently AFAIK use Google Chrome (not: Chromium) or buy decoders from Fluendo.

In the past, the Adobe GMP plugin was used to decode H.264/AAC:
    https://bugzilla.mozilla.org/show_bug.cgi?id=1266195
but that plugin is gone now.

The manifest.json file shipped with Widevine CDM specifies:
    "x-cdm-codecs": "vp8,vp9.0,avc1",
so Widevine seems not to contain a H.264/AAC decoder. It could be arranged with Google for Widevine CDM to ship a H.264/AAC decoder. It seems strange - for maximum security Widevine should not use external *software* decoders (such as ffmpeg) because this would reveal to them the raw H.264 data which could be sniffed. If Widevine would use integrated decoders, the content could only be sniffed uncompressed which would cause quality degradation on re-compression.