GNOME Bugzilla – Bug 792837
Eiphany changes system volume level when .volume is set on HTMLAudioElement
Last modified: 2018-01-23 18:23:07 UTC
Created attachment 367325 [details] Simple HTML file that demonstrates the problem Repro steps appears to be: 1) Turn system volume low 2) Create audio element. 3) Set audio element .src to a valid source. 4) Set audio element .volume to high value that isn't 1 (0.9 for example). Observe: System audio is set to near max volume. This is really jarring and damaging to my ears when I'm listening to music with headphones and a web page randomly cranks my system volume to max.
TL;DR: You must be using one of the few remaining distros to not disable PulseAudio's hated flat volumes feature. You should ask your distro to disable it. (Alternatively: perhaps you have it turned on in your PulseAudio configuration.) There are various old bugs and mailing list threads and IRC meeting logs with epic technical arguments about this... suffice to say: the conclusion is that WebKit is definitely not going to change its behavior, and the dozens of unrelated affected applications are probably not going to change their behavior either, and so distros must disable flat volumes. I know at least Ubuntu, Fedora, and Arch all have done so (Ubuntu long ago, Fedora and Arch more recently).I'm not sure if PulseAudio upstream ever changed its default, but we did get buy-in from one of the PulseAudio maintainers before making this change in Fedora. Some background reading, if you're interested: bug #675217, bug #680779, https://bugs.webkit.org/show_bug.cgi?id=118974, and https://bugzilla.redhat.com/show_bug.cgi?id=1265267. *** This bug has been marked as a duplicate of bug 675217 ***
P.S. You'll want to stay away from YouTube, since it sets WebKit's volume to 1.0 (full) via JavaScript when starting a video, and PulseAudio helpfully changes your system volume accordingly. That's CVE-2013-7324 (https://bugzilla.gnome.org/show_bug.cgi?id=675217#c12), which will never be fixed. I'm not sure, but I think it might be the only CVE assigned for a hearing damage vulnerability....
Thanks for the response and background info links. Ugh what a mess. Sorry I didn't find the duplicate bug when I filed this. My searches didn't turn it up. I'll talk to my distro (GuixSD) and try to get flat volumes disabled by default. Thanks again for your time!