1326512 - Firefox only uses Jack's system ports

Status: RESOLVED INVALID

(Core :: Audio/Video: cubeb, defect)

Description

[to7m]

Attachment: possibly relevant asound.conf

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:50.0) Gecko/20100101 Firefox/50.0
Build ID: 20161213204721

Steps to reproduce:

Tried to play this video: https://www.youtube.com/watch?v=sHlkVrdBKR8 (the same problem happens with other videos).
I also tried to find how to change Firefox's output device/port.


Actual results:

A new Jack client appeared called "Firefox", which connected directly to the system Jack ports. This caused the audio to play unaltered through my headphones without the normal layer of processing provided by my "Apps Out" Jack client. This means I'll have to disconnect this connection and connect Firefox to Apps Out each time I play a new audio stream.
I couldn't find any options in Firefox to change which ports to connect to, or which sound server.


Expected results:

Firefox should have used my ALSA loopback device as it did before becoming Jack-aware. I'll attach /etc/asound.conf in case that's relevant.
There should also be an easy to find setting in Firefox to specify which audio server and port to send audio to.

Comment 1

[Adrian Florinescu [:aflorinescu]]

To7m, my knowledge related to this issue is rather limited, so please check http://jackaudio.org/faq/pulseaudio_and_jack.html. It appears to me that Pulse and Jack are not supposed to run in paralel. I'm not sure how Firefox should behave or how to specify which audio server and port to send audio to. In order to advance this issue further and involve somebody more knowledgeable, I'm setting the component to audio/video.

Comment 2

[to7m]

Pulse and Jack tend to mix together fairly well if they're properly set up. I don't have PulseAudio installed, which might complicate things for anyone trying to troubleshoot this.

Comment 3

[Randell Jesup [:jesup] (needinfo me)]

Firefox now requires Pulse on Linux... That may be what's changed.  What Firefox version were you using?

Comment 4

[to7m]

I'm on version 50.1.0, and this problem is quite recent - I think I reported it a day after I realised what was happening. Since this started, I've also been getting problems where videos won't play at first unless I click them a few times, maybe that's relevant...

I tried installing pulse, running it, then restarting Firefox, but Firefox still only outputted audio through its Jack client. It seems that Firefox plays through my ALSA-Jack Loopback device (default in my asound.conf) fine if I prevent Jack from running when I hit play, and then start Jack afterwards, which indicates that Pulse isn't required as Firefox can still play through ALSA.

Comment 5

[to7m]

I found a couple of bug reports which might be relevant:

https://bugzilla.mozilla.org/show_bug.cgi?id=812900 - it seems from this that a workaround of setting "media.use_cubeb" to false worked before, but this setting is no longer in about:config.
https://bugzilla.mozilla.org/show_bug.cgi?id=803042 - this one suggests Firefox is meant to read asound.conf but isn't doing so properly for some reason.

When I play a video with the audio going through Firefox's Jack client, the audio xruns with increasing frequency the longer the video plays, and the audio and video drifts out of sync. Maybe this is because Jack instances make Firefox think it will be able to use Pulse for resampling, and then when it realises it can't communicate with Pulse for whatever reason, it just sends unprocessed audio to Jack?

At the moment I'm still able to play videos by starting Firefox and starting a video before starting Jack and keeping Firefox open. I think after a while Firefox randomly reverts to Jack, but I can't test this easily.

Comment 6

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

Firefox release is now 53, and now requires Pulse, can you reproduce on 53? Otherwise we should close this.

> but this setting is no longer in about:config.

Note that you can add settings manually. Not all settings are listed.