The new Firefox uses ffmpeg by default, instead of gstreamer. To fix it, set `media.fragmented-mp4.gmp.enabled` to `false`. It works for some other people but do it on your own risk.

@Ananyo:

Note that GStreamer only applies to the Linux platform and the OP is on Windows 10, so this doesn't apply.

Anyway the media.fragmented-* prefs have been replaced in Firefox 44 by plain media prefs.

• media.fragmented-mp4.gmp.enabled -> media.gmp.decoder.enabled
• media.fragmented-mp4.enabled -> media.mp4.enabled

Hi thsecmaniac

Are you playing the videos from start to end or are you stopping videos before they have finished?

Ananyo said

The new Firefox uses ffmpeg by default, instead of gstreamer. To fix it, set `media.fragmented-mp4.gmp.enabled` to `false`. It works for some other people but do it on your own risk.

cor-el said

@Ananyo: Note that GStreamer only applies to the Linux platform and the OP is on Windows 10, so this doesn't apply. Anyway the media.fragmented-* prefs have been replaced in Firefox 44 by plain media prefs.

• media.fragmented-mp4.gmp.enabled -> media.gmp.decoder.enabled
• media.fragmented-mp4.enabled -> media.mp4.enabled

---

Hi thsecmaniac

Are you playing the videos from start to end or are you stopping videos before they have finished?

cor-el is right. I didn't see the "media.fragmented-mp4.gmp.enabled" option but I saw the "media.gmp.decoder.enabled" and " media.mp4.enabled" option. However, When I change the value of "media.fragmented-mp4.gmp.enabled" from false to true, It affect the sound in Facebook videos. So, I change the value back and then its sound is back to be good as usual.