Mixer control names out of control?

Mixer control names out of control?

[Peter Christensen]

Hello,

Am I the only one feeling that the names of the mixer controls in ALSA is somewhat out of control? Especially when it comes to IEC958.

First of all, the AC97 driver uses the name "IEC958 Playback SPSA". What's wrong with "IEC958 Playback Volume"?

Next, quite a few drivers do not use the SNDRV_CTL_NAME_IEC958 macro, whose purpose I suppose is to ensure that alle IEC958 mixer controls follow a 
common naming syntax. Anyway, alot of drivers for some reason uses "Output" and "Input" instead of "Playback" and "Capture". Is this on purpose?

The reason I make such a fuss about it, is that I wanted to make a structured organized mixer for GTK, so that people don't have to use the sometimes 
messy and confusing alsamixer and gnome volume control (in general, all mixers based on the ALSA Simple Mixer controls). But then it struck me that 
the simple mixer did have some potentional, and the chaos basically was based on poor sorting of elements (which you can do manually in your program), 
its inability to detect several "new" mixer control names such as (Front,Rear,Side, etc.), and then the inability to have both a Switch and a Route 
element with the same name (The ice1724 driver was force to use "IEC958 Output Switch" instead of "IEC958 Playback Switch" due to this).
It is my belief, that if the simple mixer library routines was updated, and the mixer elements got proper names, the world would be alot better.

But is this simple caused by programmers not truely knowing the ALSA naming conversion or is there some deper sence in this?

I did consider makine a patch which changed the whole naming thing, but it would probably be to vital for people to accept?!

Thanks
   Peter Christensen


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Re: Mixer control names out of control?

[Lee Revell]

On Sat, 2004-11-27 at 10:26 +0100, Peter Christensen wrote:
> Am I the only one feeling that the names of the mixer controls 
> in ALSA is somewhat out of control? Especially when it comes 
> to IEC958.

While we are at it can we _please_ change IEC958 to SPDIF?  Normal users
have no idea what IEC958 is.

Lee  





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Mixer control names out of control?

[Peter Zubaj]

>First of all, the AC97 driver uses the name "IEC958 Playback SPSA".
What's wrong with "IEC958 Playback Volume"?

IEC958 Playback SPSA - this is not volume - this controls what AC97
slot will be used for spdif output.

AFAIK
simple mixer element != kernel mixer control. simple mixer element can
containd 6 kernel controls (mayby more):
Playback Volume
Playback Switch
Playback Route

Capture Volume
Capture Switch
Capture Route

>Front,Rear,Side
I think there is not constraint on names, there is only recomendation.
On some cards you are unable to fit to default names, because you want
name something what has diffrent meaning as control on other card.
Have you better names for this ?

Peter Zubaj
____________________________________
http://www.pobox.sk/ - najvacsi slovensky freemail





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Re: Mixer control names out of control?

[Sergey Vlasov]

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On Sat, Nov 27, 2004 at 10:26:40AM +0100, Peter Christensen wrote:
> First of all, the AC97 driver uses the name "IEC958 Playback SPSA". What's 
> wrong with "IEC958 Playback Volume"?

Because it is not a volume.  This control sets the SPSA bits in the
AC'97 Extended Audio Status and Control Register (0x2a):

- SPSA[1,0] = 00 S/PDIF source data assigned to AC-link slots 3&4
- SPSA[1,0] = 01 S/PDIF source data assigned to AC-link slots 7&8
  [2-ch Primary Codec default]
- SPSA[1,0] = 10 S/PDIF source data assigned to AC-link slots 6&9
  [4-ch Primary Codec default]
- SPSA[1,0] = 11 S/PDIF source data assigned to AC-link slots 10&11
  [6-ch Primary Codec default]

So you can set routing of some other channel (front, rear, center/LFE)
to SPDIF with this control.

However, representing SPSA as volume is really confusing.  What about
making it an enumeration instead?

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Re: Mixer control names out of control?

[Peter Christensen]

Oh, I didn't know that about SPSA, but it does make quite some sence, as I don't see why one would have volume control on IEC958 :p. But wouldn't it 
then be more correct to use an enumerated control instead of integer?

But as of simple mixer element vs. kernel mixer controls, I am fully aware, that they are not the same thing. However, the simple elements are 
generated by the ALSA library based on the names of the mixer controls. But the library basically only recognized the names listed in 
Documentation/ControlNames.txt when it sorts the simple elements, which means that elements such as Front, Rear and Side are placed almost last on my 
Aureon card, between lots of unrelated elements.
It would be nice if the library did so good a sort, so that you would have the master playback volumes together 
(Master,Front,Rear,Side,Center,LFE,Surround, etc.), the source volumes together (PCM,Wave,Line,CD,Mic,Aux,Phone,AC97,Video,PC Speaker, etc.), and the 
IEC958 controls together. And it would be very nice if the simple mixer API had a fuction to tell wether the element was actually read-only. The 
ICE1724 driver have some sort VU meter or something, which the simple mixers think are ordinary volume controls, although they're read-only.

Peter Christensen

Peter Zubaj wrote:
>>First of all, the AC97 driver uses the name "IEC958 Playback SPSA".
> 
> What's wrong with "IEC958 Playback Volume"?
> 
> IEC958 Playback SPSA - this is not volume - this controls what AC97
> slot will be used for spdif output.
> 
> AFAIK
> simple mixer element != kernel mixer control. simple mixer element can
> containd 6 kernel controls (mayby more):
> Playback Volume
> Playback Switch
> Playback Route
> 
> Capture Volume
> Capture Switch
> Capture Route
> 
> 
>>Front,Rear,Side
> 
> I think there is not constraint on names, there is only recomendation.
> On some cards you are unable to fit to default names, because you want
> name something what has diffrent meaning as control on other card.
> Have you better names for this ?
> 
> Peter Zubaj
> ____________________________________
> http://www.pobox.sk/ - najvacsi slovensky freemail
> 
> 
> 
> 



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