Reading from the output buffer

Reading from the output buffer

[Sean D'Epagnier]

Hi, I thought it would be cool to write a simple spectrum analizer to work
with any alsa player, and display it with an ncurses interface.  I have checked
various alsa docs, and I can't figure out how to read the output buffer data
back in.

Thanks,
Sean

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emu10k1 mute problems.

[Oliver Schinagl]

Hi,

I am wondering if there's a bugzilla or some place to drop a bugreport 
for my SBLive! (emu10k1)?

I have in my system 2 soundcards installed, an SBLive! emu10k1 (
00:0e.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 0a)
        Subsystem: Creative Labs SBLive! Player 5.1
        Flags: bus master, medium devsel, latency 32, IRQ 19
        I/O ports at ef20 [size=32]
        Capabilities: [dc] Power Management version 1
)
and an Onboard VIA audio thinger (
00:11.5 Multimedia audio controller: VIA Technologies, Inc. 
VT8233/A/8235/8237 AC97 Audio Controller (rev 60)
        Subsystem: ASUSTeK Computer Inc. Unknown device 810d
        Flags: medium devsel, IRQ 20
        I/O ports at 1000 [size=256]
        Capabilities: [c0] Power Management version 2

)

on a gentoo 2.6.19-r1 kernel

Now they both are working but there's one thing that seems to be going 
wrong. Since it only happens on the SBLive (the via onboard works as it 
should) it must be a bug in the emu10k1 driver.

I use the following code to mute the left resp. right channels.

    snd_mixer_selem_set_playback_switch(elem, SND_MIXER_SCHN_FRONT_LEFT, 0);
    snd_mixer_selem_set_playback_switch(elem, 
SND_MIXER_SCHN_FRONT_RIGHT, 0);

However, when muting the left channel, both channels get muted. When 
muting the the right channel, none get muted. It's not just my app that 
shows this behavious, gkrellm-volume plugin for instance does the same 
thing (wrong).


Since there aren't really much mixers that do balance properly, there 
isn't much other volume controls I can test this with. I do however 
notice in alsamixer, that below the bar, it says [MM] or [OO] on the 
SBLive!, but with the Via, I get all possibilities done, including [MO] 
or [OM].

Thanks,

Oliver

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Re: emu10k1 mute problems.

[James Courtier-Dutton]

Oliver Schinagl wrote:
> Hi,
> 
> I am wondering if there's a bugzilla or some place to drop a bugreport 
> for my SBLive! (emu10k1)?

Please report this but to the ALSA bug tracker.
https://bugtrack.alsa-project.org/alsa-bug/
See the link from
http://alsa-project.org/

I think the problem you describe is that the emu10k1 has a single mute 
control for both channels, so you do not have the left/right mute.
You need to do a test first to find out if the is separate left/right 
mute or if they are separate. If there is only one, the 
"SND_MIXER_SCHN_FRONT_LEFT" controls both channels.
Maybe it would be sensible to change the alsa-lib api so either 
SND_MIXER_SCHN_FRONT_LEFT or SND_MIXER_SCHN_FRONT_RIGHT will control 
both left/right is the mute control is shared.

> 
> Now they both are working but there's one thing that seems to be going 
> wrong. Since it only happens on the SBLive (the via onboard works as it 
> should) it must be a bug in the emu10k1 driver.
> 
> I use the following code to mute the left resp. right channels.
> 
>     snd_mixer_selem_set_playback_switch(elem, SND_MIXER_SCHN_FRONT_LEFT, 0);
>     snd_mixer_selem_set_playback_switch(elem, 
> SND_MIXER_SCHN_FRONT_RIGHT, 0);
> 
> However, when muting the left channel, both channels get muted. When 
> muting the the right channel, none get muted. It's not just my app that 
> shows this behavious, gkrellm-volume plugin for instance does the same 
> thing (wrong).
> 
> 
> Since there aren't really much mixers that do balance properly, there 
> isn't much other volume controls I can test this with. I do however 
> notice in alsamixer, that below the bar, it says [MM] or [OO] on the 
> SBLive!, but with the Via, I get all possibilities done, including [MO] 
> or [OM].
> 
> Thanks,
> 
> Oliver
> 


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Re: emu10k1 mute problems.

[Jaroslav Kysela]

On Fri, 8 Dec 2006, Oliver Schinagl wrote:

> Hi,
> 
> I am wondering if there's a bugzilla or some place to drop a bugreport 
> for my SBLive! (emu10k1)?
> 
> I have in my system 2 soundcards installed, an SBLive! emu10k1 (
> 00:0e.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 0a)
>         Subsystem: Creative Labs SBLive! Player 5.1
>         Flags: bus master, medium devsel, latency 32, IRQ 19
>         I/O ports at ef20 [size=32]
>         Capabilities: [dc] Power Management version 1
> )
> and an Onboard VIA audio thinger (
> 00:11.5 Multimedia audio controller: VIA Technologies, Inc. 
> VT8233/A/8235/8237 AC97 Audio Controller (rev 60)
>         Subsystem: ASUSTeK Computer Inc. Unknown device 810d
>         Flags: medium devsel, IRQ 20
>         I/O ports at 1000 [size=256]
>         Capabilities: [c0] Power Management version 2
> 
> )
> 
> on a gentoo 2.6.19-r1 kernel
> 
> Now they both are working but there's one thing that seems to be going 
> wrong. Since it only happens on the SBLive (the via onboard works as it 
> should) it must be a bug in the emu10k1 driver.
> 
> I use the following code to mute the left resp. right channels.
> 
>     snd_mixer_selem_set_playback_switch(elem, SND_MIXER_SCHN_FRONT_LEFT, 0);
>     snd_mixer_selem_set_playback_switch(elem, 
> SND_MIXER_SCHN_FRONT_RIGHT, 0);

Wrong code. You have to use snd_mixer_selem_set_playback_switch_all() if
snd_mixer_selem_has_playback_switch_joined() flag is set. Perhaps, single 
channel operations should return an error in this case to show the broken
part to application developers.

						Jaroslav

-----
Jaroslav Kysela <perex@suse.cz>
Linux Kernel Sound Maintainer
ALSA Project, SUSE Labs

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