[alsa-devel] Issue with Alsa and PulseAudio
Hello, I have a media application that uses alsa as its sound renderer. It has worked on numerous systems without any problems until I came across a mandriva distro that bundles with PulseAudio. The alsa pulseaudio plugin is installed correctly, however I am having weird problems.
When I am setting up my hw params, and I call snd_pcm_hw_params_any(), I get an "Operation not permitted" error. I am not sure why this is happening, anyone else see this before? I am using pulseaudio version 0.9.9 and alsa 1.0.16.
Thanks in advance! _________________________________________________________________ Be the filmmaker you always wanted to be—learn how to burn a DVD with Windows®. http://clk.atdmt.com/MRT/go/108588797/direct/01/
Hi Ash,
Ash wrote:
Hello, I have a media application that uses alsa as its sound renderer. It has worked on numerous systems without any problems until I came across a mandriva distro that bundles with PulseAudio. The alsa pulseaudio plugin is installed correctly, however I am having weird problems.
When I am setting up my hw params, and I call snd_pcm_hw_params_any(), I get an "Operation not permitted" error. I am not sure why this is happening, anyone else see this before? I am using pulseaudio version 0.9.9 and alsa 1.0.16.
Thanks in advance!
I'm the Mandriva PulseAudio maintainer. Most distros are now shipping PA by default now so I doubt your problem will be specific to Mandriva :)
However, I'm not expert enough in the ALSA API to know specifically what snd_pcm_hw_params_any() actually does, but I'd imagine (this is just a guess) that this is something that is either not implemented in the IOPLUG system (on which the pulseaudio alsa plugin builds) or something not implemented in the pulseaudio alsa plugin itself.
Hopefully someone more versed in this can explain the reason why it fails. :)
Col
At Tue, 26 Aug 2008 16:21:13 +0100, Colin Guthrie wrote:
Hi Ash,
Ash wrote:
Hello, I have a media application that uses alsa as its sound renderer. It has worked on numerous systems without any problems until I came across a mandriva distro that bundles with PulseAudio. The alsa pulseaudio plugin is installed correctly, however I am having weird problems.
When I am setting up my hw params, and I call snd_pcm_hw_params_any(), I get an "Operation not permitted" error. I am not sure why this is happening, anyone else see this before? I am using pulseaudio version 0.9.9 and alsa 1.0.16.
Thanks in advance!
I'm the Mandriva PulseAudio maintainer. Most distros are now shipping PA by default now so I doubt your problem will be specific to Mandriva :)
However, I'm not expert enough in the ALSA API to know specifically what snd_pcm_hw_params_any() actually does, but I'd imagine (this is just a guess) that this is something that is either not implemented in the IOPLUG system (on which the pulseaudio alsa plugin builds) or something not implemented in the pulseaudio alsa plugin itself.
Hopefully someone more versed in this can explain the reason why it fails. :)
There is no alsa-lib code that returns -EPERM by itself. Usually this error comes from the ioctl, but in this case, it must be from pulse plugin. And, pcm_pulse.c contains no EPERM, it must come from the pulseaudio itself.
So, my rough guess is that PA is running by a different user (e.g. root) that doesn't allow you to connect it.
Of course, first I'd do is to upgrade alsa-lib and alsa-plugins. 1.0.16 is fairly old.
Takashi
Takashi Iwai wrote:
There is no alsa-lib code that returns -EPERM by itself. Usually this error comes from the ioctl, but in this case, it must be from pulse plugin. And, pcm_pulse.c contains no EPERM, it must come from the pulseaudio itself.
So, my rough guess is that PA is running by a different user (e.g. root) that doesn't allow you to connect it.
Interesting analysis, thanks Takashi.
Ash, if you want me to help with debugging, I am usually on #mandriva-cooker and #pulseaudio on IRC (nick coling).
If I don't answer after a ping it means I'm not there!
Of course, first I'd do is to upgrade alsa-lib and alsa-plugins. 1.0.16 is fairly old.
Ash, if you think this would help, I can backport these two packages on Mandriva for the 2008.1 version but the driver will have to remain at 1.0.16. (actually a current backport would get the 1.0.18rc2's).
And Takashi, do you age faster than most humans? 1.0.17 only went final few weeks ago!!! (although I accept there have been several good bugfixes since!!)
Cheers
Col
At Tue, 26 Aug 2008 16:39:25 +0100, Colin Guthrie wrote:
Of course, first I'd do is to upgrade alsa-lib and alsa-plugins. 1.0.16 is fairly old.
Ash, if you think this would help, I can backport these two packages on Mandriva for the 2008.1 version but the driver will have to remain at 1.0.16. (actually a current backport would get the 1.0.18rc2's).
This shouldn't be a problem as long as you use PA.
And Takashi, do you age faster than most humans? 1.0.17 only went final few weeks ago!!! (although I accept there have been several good bugfixes since!!)
Well, I thought he mentioned alsa-*lib* 1.0.16. Actually it wasn't certain what version was that...
Takashi
At Tue, 26 Aug 2008 16:39:25 +0100, Colin Guthrie wrote:
Of course, first I'd do is to upgrade alsa-lib and alsa-plugins. 1.0.16 is fairly old.
Ash, if you think this would help, I can backport these two packages on Mandriva for the 2008.1 version but the driver will have to remain at 1.0.16. (actually a current backport would get the 1.0.18rc2's).
This shouldn't be a problem as long as you use PA.
And Takashi, do you age faster than most humans? 1.0.17 only went final few weeks ago!!! (although I accept there have been several good bugfixes since!!)
Well, I thought he mentioned alsa-*lib* 1.0.16. Actually it wasn't certain what version was that...
Takashi
Thanks Colin, Takashi.
The thing is, I've noticed other applications such as aplay or amarok call the same function and not exhibit the same behavior. That's why I am not sure what I am doing wrong.
Also intersetingly enough, if I do not use the "default" ALSA_DEVICE_DEFAULT, and instead use "front" (which I believe is direct access to alsa driver, whereas "default" goes through pulseaudio), strange things happen. For example, setting a rate or channels returns -22 Invalid Argument.
I am not sure if I need to change or upgrade alsa. I just want to get to the bottom of this with existing pulseaudio/alsa since other players seem to work.> To: alsa-devel@alsa-project.org> From: gmane@colin.guthr.ie> Date: Tue, 26 Aug 2008 16:39:25 +0100> CC: alsa-devel@alsa-project.org; hashbrown100@hotmail.com> Subject: Re: [alsa-devel] Issue with Alsa and PulseAudio> > Takashi Iwai wrote:> > There is no alsa-lib code that returns -EPERM by itself.> > Usually this error comes from the ioctl, but in this case, it must be> > from pulse plugin. And, pcm_pulse.c contains no EPERM, it must come> > from the pulseaudio itself.> > > > So, my rough guess is that PA is running by a different user> > (e.g. root) that doesn't allow you to connect it.> > Interesting analysis, thanks Takashi.> > Ash, if you want me to help with debugging, I am usually on > #mandriva-cooker and #pulseaudio on IRC (nick coling).> > If I don't answer after a ping it means I'm not there!> > > Of course, first I'd do is to upgrade alsa-lib and alsa-plugins.> > 1.0.16 is fairly old.> > Ash, if you think this would help, I can backport these two packages on > Mandriva for the 2008.1 version but the driver will have to remain at > 1.0.16. (actually a current backport would get the 1.0.18rc2's).> > And Takashi, do you age faster than most humans? 1.0.17 only went final > few weeks ago!!! (although I accept there have been several good > bugfixes since!!)> > > Cheers> > Col> > > -- > > Colin Guthrie> gmane(at)colin.guthr.ie> http://colin.guthr.ie/%3E > Day Job:> Tribalogic Limited [http://www.tribalogic.net/%5D%3E Open Source:> Mandriva Linux Contributor [http://www.mandriva.com/%5D%3E PulseAudio Hacker [http://www.pulseaudio.org/%5D%3E Trac Hacker [http://trac.edgewall.org/%5D%3E > _______________________________________________> Alsa-devel mailing list> Alsa-devel@alsa-project.org> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel _________________________________________________________________ Be the filmmaker you always wanted to be—learn how to burn a DVD with Windows®. http://clk.atdmt.com/MRT/go/108588797/direct/01/
Ash wrote:
Thanks Colin, Takashi.
The thing is, I've noticed other applications such as aplay or amarok call the same function and not exhibit the same behavior. That's why I am not sure what I am doing wrong.
Well amarok presumably uses xine... aplay tho' is probably more interesting. I presume you are passing the same values etc. as e.g. aplay?
Also intersetingly enough, if I do not use the "default" ALSA_DEVICE_DEFAULT, and instead use "front" (which I believe is direct access to alsa driver, whereas "default" goes through pulseaudio), strange things happen. For example, setting a rate or channels returns -22 Invalid Argument.
Don't use "front", you should use "default". "front" will only exist on some sound hardware AFAIK, and in the case that the user has selected their "default" device to route through pulseaudio, you should respect this.
I'm sure there is probably a technical reason why "front" does not let you set rate or channels (probably because it represents the front speakers system of a multi-channel setup), but I'm sure someone more familiar with the API will be able to enlighten you :)
I am not sure if I need to change or upgrade alsa. I just want to get to the bottom of this with existing pulseaudio/alsa since other players seem to work.
Indeed. If aplay is calling this function and works via pulseaudio, then it stands to reason so should you!
Col
Hi,
Ash <hashbrown100 <at> hotmail.com> writes:
When I am setting up my hw params, and I call snd_pcm_hw_params_any(), I get
an "Operation not permitted"
error. I am not sure why this is happening, anyone else see this before? I am
using pulseaudio version 0.9.9
and alsa 1.0.16.
did you figure out what the problem was? I am having the same problem under Ubuntu, alsa-lib 1.0.17 and pulseaudio 0.9.10.
Thank you in advance, Ludovico
participants (4)
-
Ash -
Colin Guthrie -
Ludovico Cavedon -
Takashi Iwai