On Samstag 04 November 2006 19:00, Martin Wache wrote:
> Stefan Lucke schrieb:
> > On Samstag 04 November 2006 13:56, Martin Wache wrote:
> >> Stefan Lucke schrieb:
> >>> On Donnerstag 02 November 2006 16:40, Juha Pahkala wrote:
> >>>> Stefan Lucke wrote:
> >>>>> Quoting Juha Pahkala <[EMAIL PROTECTED]>:
> >>>>>
> >>>>>   
> >>>>>> Just updated my softdevice from 0.2.2 to 0.3.0. Picture-wise, it seems
> >>>>>> to be an improvement, I'm not sure whether I'm imagining things but the
> >>>>>> picture does seem crispier on the primary head of my g400... although I
> >>>>>> also updated dfb so not sure who's to blame ;)
> >>>>>>     
> >>>>> Can you try:
> >>>>> a. unmute main pcm with alsamixer, or
> >>>>> b. comment out line 15 of audio_alsa.c: #define NO_MIXER
> >>>>>   
> >>>> Hi Stefan,
> >>>>
> >>>> Option A didn't make a difference but commenting out the NO_MIXER define
> >>>> fixed the problem! So thank you for your help (as well as softdevice in
> >>>> general ;)
> >>> Can you try the following patch which makes use of alsa mixer 
> >>> selectable via OSD ?
> >>>
> >> I fear some strange effects if one switches the use of alsa mixer via
> >> the osd. Consider the following, the volume of vdr is at some low
> >> position, the alsa mixer is in high volume position. One switches from
> >> no mixer to mixer. The audio wont be scaled any more so the volume goes
> >> dramatically up, since the alsa mixer is still in a high volume
> >> position.
> > 
> > Yes I'm aware of this, but this problem already exists. Think of
> > an external amplifier connected via S/P-DIF. Volume is set to low position
> > and controlled by either alsa mixer or software scaler. Then consider
> > a switch to an AC3 station, for which volume control is done by
> > external AC3 decoder/amplifier  only. User and his/her neighbours will
> > notice a volume difference too.
> >
> Well, the softdevice (just like the FF cards) can not change the volume
> of an AC3 stream, we cannot change that. But that doesn't mean that we
> have to introduce more traps which could hurt the ears of users even if
> they don't use AC3 equipment ;-).
> And I guess anyone who has AC3 equipment connect anyway only uses the
> external amplifier to change the volume, this is the only sensible option.
> 
> >> Now one changes the volume of the vdr by one step, the volume 
> >> will jump to a low volume again, because the alsa mixer will go down to
> >> a low volume. If one now switches back to no alsa mixer option, the
> >> volume will instantly go down even more, since now the audio is scaled
> >> (or something else, scale_Factor is unset)...
> >>
> >> Some of those problems can surely be fixed, but that will make it more
> >> complicated. If one has to be able to select to use the alsa mixer I
> >> would prefer a command line option.
> > 
> > A command line option has the disadvantage, that the calling script has
> > to be edited. In a vdr only setup, a normal user has no chance to do this.
> > 
> Oh, come on. Connecting AC3 equipment is not something a normal user
> does every day, and during installation of the softdevice the command
> line has to be setup anyway.
> 
> >> But maybe you can explain me what actually the problem is? Of course if
> >> the AC3 data would be scaled, that would make the useless, but as far as
> >> I see, that is not the case. So the is the problem the alsa mixer setting?
> > 
> > Yes the problem is the mixer settings. on my other test box I noticed the 
> > situation
> > too, but I could fix it by alsamixer and unmuting main + pcm mixer and give 
> > them
> > a reasonable volume level than default.

And now as I fixed my installation on this box, mixer values are restored at
startup.

> > 
> > So there a many ways to control volume:
> > a. external amplifier (S/P-DIF)
> > b. external amplifier (via line out)
> > c. PC-Speaker
> > 
> > Things to be controlled by vdr / PC
> > a. alsa master volume + mute
> > b. alsa PCM mixer volume + mute
> > c. alsa line out  + S/P-DIF out (mute ?)
> > d. alsa output switches (s short summary from my setup)
> >    - IEC958 5V, Copyright, In Monitor, Loop, ..
> >    - Line-In Mode: Line-In, Rear Output, Bass output
> >    - Mic-In Mode: Mic-in, Center/LFE Output, 
> > 
> > Controlling alsa in total, is enough for separate plugin I guess.
> > 
> 
> There is the AVolCtl-plugin ;-)

Hey, thats _is_ the solution. Did a short test. This plugin needs just the
usual APIVERSION patch to compile with vdr-1.4.0.

So I'll add only a command line switch for those without avolctl.

> As you said, we can not control everything... If I understand that
> correctly AC3 passthrough works with NO_MIXER defined and with the
> correct alsa-mixer settings at the start of the softdevice?
> Maybe it is time for a FAQ, and we put all this in the FAQ.
> 

-- 
Stefan Lucke
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