1377696 - No sound with video playback rate > 4x

Status: RESOLVED INVALID

(Core :: Audio/Video: Playback, enhancement, P3)

Description

[Johannes Pfrang [:johnp]]

Using the Playback Speed Add-On[1] or simple javascript[2] to set video playback rate to > 4x results in loss of audio. Setting playback rate <= 4x restores audio.  

[1] https://addons.mozilla.org/en-US/firefox/addon/playback-speed/
[2] document.getElementsByTagName('video')[0].playbackRate = 4.1

Comment 1

[Johannes Pfrang [:johnp]]

MDN says sound should only be muted outside [0.25, 5.0]: https://developer.mozilla.org/en-US/docs/Web/API/HTMLMediaElement/playbackRate

Comment 2

[JW Wang [:jwwang] [:jw_wang]]

Hi ChunMin,
Please check this issue. Thanks!

Comment 3

[myaseen98]

Hi, I really want this issue fixed, is there any way I can help with the debugging? I'm new to this so Idk what code to work on etc.

Comment 4

[Johannes Pfrang [:johnp]]

AFAIK it's simply these definitions that are "wrong" (compared to MDN). Maybe those could be converted to about:config preferences / StaticPrefs, so people can choose for themselves, but a Mozilla employee would have to decide if that's OK.

Comment 5

[myaseen98]

(In reply to Johannes Pfrang [:johnp] from comment #4)

AFAIK it's simply these definitions that are "wrong" (compared to MDN). Maybe those could be converted to about:config preferences / StaticPrefs, so people can choose for themselves, but a Mozilla employee would have to decide if that's OK.

Is this something I can edit locally on my pc?

Comment 6

[Johannes Pfrang [:johnp]]

Not without recompiling or patching the correct place in the binary with e.g. a hex editor.

Comment 7

[Alastor Wu [:alwu]]

I've submitted a change to modify the MDN page, so close this bug because this is not gecko issue.