In amarok in equalizer changing position of the first slider doesn't change the sound. I believe it should be pre-amplifier, but taking in consideration this bug https://bugs.kde.org/show_bug.cgi?id=280318 it is not clear.
When I used xine-backend for phonon (with I don't know why is unmaintained) I didn't had this problem. Also in other backends for phonon there no such problem, because there's no equalizer at all... That's why I believe the gstreamer-backend is to blame.
Steps to Reproduce:
1. Run amarok
2. Play some file
3. Open equalizer
4. Change position of first slider. No change in sound should be noticed.
The GStreamer equalizer actually does not have a preamp. Amarok shouldn't be displaying one as phonon-gstreamer does not report the existance of one.
If GStreamer does not have a preamp, so how it works in Clementine? It uses gstreamer and it has good working preamp.
(In reply to comment #2)
> If GStreamer does not have a preamp, so how it works in Clementine? It uses
> gstreamer and it has good working preamp.
Because Clementine uses gstreamer directly, not Phonon.
Which exact Amarok version is this about? Please make sure you sue Amarok 2.6 and report back.
Closing for lack of feedback.
Oh, I can confirm and reproduce this bug, reopening.
The problem is interface between EngineController and Equalizer, which is so silly that it cannot communicate non-presence of the preamp, also the Equalizer GUI must be adapted to be able to disable gray-out preamp. Shouldn't be hard to do, marking as JJ.
how should I check which Effect Parameter is supported by phonon or should I just hard code it for preamp ?
Can I assume that if at all preamp is present then it will the first element of Effect Parameter list ??
(In reply to comment #8)
> Can I assume that if at all preamp is present then it will the first element
> of Effect Parameter list ??
Yes, in the first version of the patch.
Created attachment 77354 [details]
Is this the desired output ? ( Preamp is disabled in the image though the effect is not porperly visible )
Additional Change : Fixed top and bottom labels of first slider. Earlier band name label was at the top and slider value label was at the bottom for first slider ( assuming it was a bug ).
(In reply to comment #10)
> Created attachment 77354 [details]
> Equalizer snapshot
> Is this the desired output ? ( Preamp is disabled in the image though the
> effect is not porperly visible )
Yep, looks good.
> Additional Change : Fixed top and bottom labels of first slider. Earlier
> band name label was at the top and slider value label was at the bottom for
> first slider ( assuming it was a bug ).
I think it was intended, but confusing, so this is a good change.
Now it's time for http://reviewboard.kde.org/ - please do attach the screenshot there too.
Git commit e344f608faf236e8faa455e0516f55d4ffeee80c by Matěj Laitl, on behalf of Harsh Gupta.
Committed on 15/04/2013 at 15:55.
Pushed by laitl into branch 'master'.
EqualizerDialog: disable pre-amplifier slider if it isn't supported
* Pre-apmlifier in equalizer is now only enabled if it is actually
supported; patch by Harsh Gupta.
DIGEST: Amarok now disables pre-amp slider if it isn't available
M +2 -0 ChangeLog
M +13 -7 src/EngineController.cpp
M +2 -0 src/EngineController.h
M +7 -3 src/dialogs/EqualizerDialog.cpp
M +4 -4 src/dialogs/EqualizerDialog.ui