I can't reproduce this here at all, with any backend, both the gstreamer 4.6.0 backend and the vlc 0.5.0 backend work fine.

Very strange, it works if I write a basic phonon application and add a volume slider, but not in amarok. The proper slot is called and everything should work, but it doesn't. I will investigate further.

Okay, I found the problem (or at least the problematic line). If I comment the following line in Engine src/EngineController.cpp:154, that reads
    m_dataPath = Phonon::createPath( m_media.data(), m_audioDataOutput.data() );
the volume control in amarok works as expected. I'm not sure why exaclty, but it is a solution to my problem.

why is it working then for me with the default backends? And I don't remember it not working even with previous versions...

The previous version (2.4.3) works fine. The bug seems to be introduced in 2.5.0. I can't explain it better at the moment. All I know is, if I remove the mentioned line, it works. Maybe something about the fact that Phonon::createPath is called twice with the same source and different sinks? Seems unlikely, but then again I'm not familiar with the code.

There was a code change in that section before 2.5.0 but that actually fixed a bug with the slider. I marked it as a regression, even if I can't reproduce it, it's up to the developers now.

I have the same issue using amarok 2.5.0 with kde 4.8.1 on Arch.
Changing volume in amarok doesn't do anything unless I stop and start playback.
Also mouse wheel up/down over amarok systray icon doesn't work.

This one is fixed in git.

I'm guessing that the commit in question is 219298b2481cb228d05f8c963d28b40500ad2507. I just tried the git master branch and unfortunately the problem is not solved.

*** Bug 297436 has been marked as a duplicate of this bug. ***

I can't reproduce thus with:
Amarok Version: 2.5-GIT (v2.5.0-171-gce15c15)
KDE Version: 4.8.00 (4.8.0
Qt Version: 4.7.4
Phonon Version: 4.6.0
Phonon Backend: VLC (0.4.1)

nor with Phonon Backend: GStreamer (4.6.0)

Is there anything else that could cause this? ex: non working or strange pulseaudio configuration.

Does the volume level perhaps change with a big delay?

Any news on this?

Still using amarok 2.5 and using KDE 4.8.2 and, at the moment, the Xine backend for phonon, I still experience the bug.  It's definitely not an issue of delay, the volume level is adjusted the moment you switch audio files, and is not adjusted during playback.

I've also noticed that playback seems to randomly stop in the middle of the playlist once in a while, but it's possible this is entirely unrelated.

Fred, please do not use the xine backend, it is deprecated and unmaintained since over a year. Please use either the gstreamer or the vlc backend. Both work fine for me.

I'm unable to get amarok to play at all with the gstreamer backend to phonon; both the vlc and xine backends exhibit the bug with volume adjustments only being applied when switching files (or restarting playback of the current file).

Fred: do you have the gstreamer plugins installed?

I can confirm this with:

Arch Linux x86_64
Kernel version: 3.3.6
Amarok Version: 2.5.0
KDE Version:  4.8.3 (4.8.3)
Qt Version: 4.8.1
Phonon Version: phonon 4.6.0
Phonon Backend: VLC (0.5.0)

Does this still happen with the git versions?

If it does, please post the contents of the Diagnostics dialog in the Help menu.

I can't reproduce this with current Amarok 2.5-git and the phonon-backend-vlc 0.5.0

I've just installed amarok 2.5-git and I'm still having the same problem. The volume slider stills not working while playing a song.

(In reply to comment #20)
> I've just installed amarok 2.5-git and I'm still having the same problem.
> The volume slider stills not working while playing a song.

Please provide the information asked for by Bart in comment #18

(In reply to comment #21)
> (In reply to comment #20)
> > I've just installed amarok 2.5-git and I'm still having the same problem.
> > The volume slider stills not working while playing a song.
> 
> Please provide the information asked for by Bart in comment #18

Amarok Diagnostics

Amarok Version: 2.5-GIT
KDE Version: 4.8.3 (4.8.3)
Qt Version: 4.8.1
Phonon Version: 4.6.0
Phonon Backend: VLC (0.5.0)
PulseAudio: No

Amarok Scripts:
Amarok Script Console 1.0 (stopped)
Android Amarok2 Remote 0.3 (stopped)
Lyricwiki .2 (stopped)
Ultimate Lyrics 2.06 (stopped)
Free Music Charts 1.6.0 (stopped)
Librivox.org 1.0 (stopped)
Cool Streams 1.0 (stopped)

Amarok Plugins:
Colección DAAP (disabled)
Colección MySQLServer (enabled)
Colección MySQLe (enabled)
Colección UPnP (disabled)
Colección de Cd de audio (enabled)
Colección de MTP (enabled)
Colección de iPod, iPad e iPhone (enabled)
Colección universal de almacenamiento masivo (enabled)
Ampache (disabled)
Directorio de podcast (enabled)
Jamendo (enabled)
Last.fm (enabled)
MP3tunes (disabled)
Tienda Magnatune (enabled)
Tienda de música MP3 (enabled)
gpodder.net (disabled)
Motor de archivos locales y almacenamiento USB (enabled)
Motor de compartición NFS (enabled)
Motor de compartición SMB (Windows) (enabled)

Thank you for the fast feedback.

had the issue today (2012-Jun-15) with current GIT version of amarok and phonon-vlc in version 0.4.0 (gentoo stable). The issue was resolved either by using phonon-gstreamer as backend or updating phonon-vlc to 0.5.0 (along with phonon in version 4.6.0)
Maybe this information is useful for you.

Thank you for the feedback, Simon. Since nobody in the Amarok Team can reproduce this it is rather difficult to know where the problem lies.

Really strange, no-one knows the difference between setups where this is reproducible and where not. Reporters, please try Amarok 2.6 beta and post its Diagnostics page if you can still reproduce this.

simon suggests it is connected to having phonon-vlc <= 0.4, but Mauro Bender negates that.

(In reply to comment #26)
> Really strange, no-one knows the difference between setups where this is
> reproducible and where not. Reporters, please try Amarok 2.6 beta and post
> its Diagnostics page if you can still reproduce this.
> 
> simon suggests it is connected to having phonon-vlc <= 0.4, but Mauro Bender
> negates that.

Since the last update the volume slider started to work again. The versions of the different components (like phonon, phonon-vlc, amarok, etc...) except for kde (now it's 4.8.4) is the same. The thing, what I think that may fixed the problem, was that for go back to the non-git version I've to clean the amarok config repository ($HOME/.kde4/share/apps/amarok) because an error about the amarok version that created the amarok database was newer than the amarok version that I've just installed. So, after doing that and rebuilding my collection I tried a song and the volume slider worked perfectly.

Thank you for the feedback, Mauro. Let's assume this is fixed with an updated vlc backend. Please feel free to reopen if this still happens with Phonon 4.6, phonon-backend-vlc 0.5.0 and Amarok 2.6, to be released any day now.

I'm seeing this problem on Ubuntu quantal with Amarok 2.6.0. The volume control doesn't work while a track is playing, unless I pause it, then unpause it. The volume control then works.

Amarok Diagnostics

Amarok Version: 2.6.0
KDE Version: 4.9.4
Qt Version: 4.8.3
Phonon Version: 4.6.0
Phonon Backend: GStreamer (4.6.2)
PulseAudio: Yes

Amarok Scripts:
    Amarok Script Console 1.0 (stopped)
Lyricwiki .2 (running)
Free Music Charts 1.6.0 (running)
Librivox.org 1.0 (running)
Cool Streams 1.0 (running)

Amarok Plugins:
    AudioCd Collection (enabled)
DAAP Collection (disabled)
MTP Collection (enabled)
MySQLServer Collection (enabled)
MySQLe Collection (enabled)
UPnP Collection (disabled)
Universal Mass Storage Collection (enabled)
iPod, iPad & iPhone Collection (enabled)
Ampache (disabled)
Jamendo (enabled)
Last.fm (enabled)
MP3 Music Store (enabled)
MP3tunes (disabled)
Magnatune Store (enabled)
Podcast Directory (enabled)
gpodder.net (disabled)
Local Files & USB Mass Storage Backend (enabled)
NFS Share Backend (enabled)
SMB (Windows) Share Backend (enabled)

(In reply to comment #29)
> I'm seeing this problem on Ubuntu quantal with Amarok 2.6.0. The volume
> control doesn't work while a track is playing, unless I pause it, then
> unpause it. The volume control then works.
> 
> Amarok Diagnostics
> 
> Amarok Version: 2.6.0
> KDE Version: 4.9.4
> Qt Version: 4.8.3
> Phonon Version: 4.6.0
> Phonon Backend: GStreamer (4.6.2)

Please upgrade your Amarok version, see http://kubuntu.org/news/amarok-27

Also if you read the comment you should know we talk about a solution in the phonon backend-vlc, please make sure you test it with that backend as well.