I have contacted Mozilla as I think this is a FireFox Issue, but have not made any progress, so I thought I would ask here in case someone else has run into this.
I am running Mageia 5 and Firefox 52.5.3. When I use Firefox to go to sites like YouTube, Netflix, Hulu, etc., The videos and audio play fine. However, no matter what video I pick from Facebook, the video plays, but there is no audio. Here's what I have done so far:
1. Cleared the cache and re-started Firefox
2. Created a brand new profile in Firefox
3. Disabled all the extensions & add-ons in Firefox
4. Tried Chrome to play the same Facebook videos.
In all cases (except #4) I can play the Facebook video, but no audio comes out. When I use Chrome, the videos play with no issues (video & audio).
I went to a site called https://www.quirksmode.org/html5/tests/video.html (recommended by Firefox support) and tested the video/audio. As indicated on the site, MP4 is not supported by Firefox and is the only sample video that did not play correctly.
I don't like Chrome because of all the information that it collects and shares with sponsors/other sites. So I would rather use Firefox. I use Thunderbird for e-mail/calendar and it integrates with Firefox well.
Any suggestions?