Arch Linux

megapink

Member

Registered: 2020-03-24

Posts: 24

jack2 mpv desynchronisation detected

So, I have installed jack2, everything has been working fine, including youtube (in the browser), renoise (DAW) and mplayer.

mpv also plays well but only up until I pause the video and try to play it again. Then I get the following error (showing all the output):

   (+) Video --vid=1 (*) (h264 1280x720 25.000fps)
   (+) Audio --aid=1 --alang=eng (*) (aac 2ch 44100Hz)
  [ao/alsa] Unable to set buffer time near: Invalid argument
  AO: [alsa] 48000Hz stereo 2ch float
  VO: [gpu] 1280x720 yuv420p
  (Paused) AV: 00:00:00 / 01:04:13 (0%) A-V: -0.000

  Audio/Video desynchronisation detected! Possible reasons include too slow
  hardware, temporary CPU spikes, broken drivers, and broken files. Audio
  position will not match to the video (see A-V status field).

  (Paused) AV: 00:00:02 / 01:04:13 (0%) A-V:  0.000 Dropped: 30

The sound doesn't play when I resume the playback (but the video rolls just fine). If I jump to another position in the video, the audio starts playing again. I also have tried playing the vids from my camera and the sound disappears there too, but the error doesn't show.

my asound.conf:

pcm.!default {
    type plug
    slave.pcm "jack"
    hint.description "Jack Audio"
}

I start jack2 in .xinitrc like this:

jackd -d alsa &

Could someone, please, help me troubleshoot this?

kulnova

Member

From: Vietnam

Registered: 2020-04-13

Posts: 3

Re: jack2 mpv desynchronisation detected

The video's playing through PulseAudio. So when you start Jack, Pulse Audio server stops working. To make both Jack and PulseAudio work well together, you need some kind of bridge. Take a look at cadence. Install cadence and enable the PulseAudio -> Jack bridge. It should work just fine.

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Musician on Arch Linux... Trying to setup a full Digital Audio Workstation on Arch Linux and I love the learning curve...

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,064

Re: jack2 mpv desynchronisation detected

There's nothing in the above output indicating that to be the case, I doubt that pulse is relevant here. It is however using the ALSA -> Jack bridge (which I know used to have some issues in certain alsa-plugin versions a while ago, not sure as to the current state of affairs), while mpv would have native jack support, what happens if you use --ao=jack instead of roundabouting over ALSA?

Last edited by V1del (2020-04-15 09:47:24)

megapink

Member

Registered: 2020-03-24

Posts: 24

Re: jack2 mpv desynchronisation detected

There's nothing in the above output indicating that to be the case, I doubt that pulse is relevant here. It is however using the ALSA -> Jack bridge (which I know used to have some issues in certain alsa-plugin versions a while ago, not sure as to the current state of affairs), while mpv would have native jack support, what happens if you use --ao=jack instead of roundabouting over ALSA?

With --ao=jack, it works perfectly well! Thank you.

BTW, not sure if I should have, but yesterday I filed a bug report here. Do you think I should close it?

megapink

Member

Registered: 2020-03-24

Posts: 24

Re: jack2 mpv desynchronisation detected

The video's playing through PulseAudio. So when you start Jack, Pulse Audio server stops working. To make both Jack and PulseAudio work well together, you need some kind of bridge. Take a look at cadence. Install cadence and enable the PulseAudio -> Jack bridge. It should work just fine.

I am using alsa, not pulseaudio though.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,064

Re: jack2 mpv desynchronisation detected

Maybe, you should definitely mention that there, they might be able to add a workaround or close it as won't fix or so,  the underlying issue is likely to be in the alsa to jack plugin of the alsa-plugins package.

megapink

Member

Registered: 2020-03-24

Posts: 24

Re: jack2 mpv desynchronisation detected

Maybe, you should definitely mention that there, they might be able to add a workaround or close it as won't fix or so,  the underlying issue is likely to be in the alsa to jack plugin of the alsa-plugins package.

Sure, added that info to the issue.

Thanks!