Bug 89159

Summary:	Audascious mono mp3 + youtube = 1000% volume
Product:	PulseAudio	Reporter:	Oscar Molin <oscarmolin>
Component:	alsa	Assignee:	pulseaudio-bugs
Status:	RESOLVED MOVED	QA Contact:	pulseaudio-bugs
Severity:	normal
Priority:	medium	CC:	lennart
Version:	unspecified
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	pulseaudio_stereo_output pulseaudio_mono_output

Description Oscar Molin 2015-02-15 23:25:03 UTC

I've already written this on audascious bug tracker and they rejected it as a pulseaudio issue. Audascious is pulseaudio-alsa-2-3 in arch linux, not sure what exact version that is but this issue has been there for along time.
Heres my old description:

I'm using audascious 3.52, arch linux x64 and intel HD audio soundcard. Audascious plays through pulseaudio to spdif.
If I play a certain mp3, which is 112kbps mono audio, and then open a youtube video while playing, the volume changes to maybe 1000%. That means it's so loud it almost breaks my speakers, and horribly distorted of course.
If I turn the audascious volume down to maybe 2%, it will now play at about the same volume as is did before when the volume was set to 100%.
This only happens when playing this file, other mp3s, aacs etc don't have this issue, and if I play the file in another player like vlc and open youtube, it doesnt happen.
So far only the combination youtube and audascious has reproduced the problem. Note that the youtube volume is no affected, only the audascious volume. The actual volume levels in pulseaudio are also not affected, it only the audascious audio that is "amplified". I have a feeling somehow this is a problem in the mp3 decoder, or that the file is corrupted, or both.
Turn down the volume before you try this. I was very surprised it could get so loud even though the audio goes through spdif to my receiver.

File to reproduce:
http://traffic.libsyn.com/legionofskanks/LOSepisode114.mp3

Comment 1 David Henningsson 2015-02-16 08:58:26 UTC

You probably want to disable "flat-volumes" in default.pa?

Comment 2 Arun Raghavan 2015-02-16 09:33:44 UTC

This doesn't actually sound like a flat-volumes problem (specific to a single file).

Could you post the output of 'pactl list' in both cases: with YouTube + a file in audacious that doesn't trigger the problem, and YouTube + the file in audacious that does trigger the problem?

Comment 3 Oscar Molin 2015-02-16 19:40:11 UTC

Created attachment 113541 [details]
pulseaudio_stereo_output

Comment 4 Oscar Molin 2015-02-16 19:40:39 UTC

Created attachment 113542 [details]
pulseaudio_mono_output

Comment 5 Oscar Molin 2015-02-16 19:49:33 UTC

Here are the requested logs. Sorry about the localization, but if you're familiar with the format I'm sure you can read it anyway.

I found no differences except that it says that one is mono, and it says that there is no channel mapping due to the file being mono and that resampling is not applicable due to the file being mono, which I don't think makes sense as I though number of channels had nothing to do with that.

I've tried some other mono mp3s I downloaded from different sources and the ones I've tried have exibited the same problem. The problem disappears only after turning youtube off, shut down audascious and start it up again as sole audio app.

Youtube shows this behavior with both flashplugin playback and html5 playback (which was used in the log) so it's not a flash issue. I use firefox btw if that matters. The logs should give enough info I hope.

I also until just recently was able to have both analog and spdif playback at the same time (that is, set a few applications to play to one and other applications plays the other) to the same soundcard, but that functionality was broken pretty recently in an update I got from Arch. This problem was there before that though. If you think that's a bug I can file it too but I don't know how to get it working again in that way. Not a big issue though, I can manage with how it is now.

Comment 6 GitLab Migration User 2018-07-30 10:18:02 UTC

-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/issues/328.

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