How to apply rate conversion in asound.conf

How to apply rate conversion in asound.conf

[Dolevo Jay]

Hi experts,

I am currently using the following asound.conf, which is pretty much
copy-paste from the link below.

asound.conf
-------------------------------------
pcm.!default {
	type plug
	slave.pcm multi
}

pcm.multi {
        type multi;
        slaves.a.pcm "hw:0,1";
        slaves.a.channels 2;
        slaves.b.pcm "hw:1,1";
        slaves.b.channels 2;

        bindings.0.slave a;
        bindings.0.channel 0;
        bindings.1.slave a;
        bindings.1.channel 1;
        bindings.2.slave b;
        bindings.2.channel 0;
        bindings.3.slave b;
        bindings.3.channel 1;
}
-------------------------------------

http://www.alsa-project.org/main/index.php/Asoundrc#Virtual_multi_channel_devices
-------------------------------------

My purpose is to apply rate conversion to the "hw:1,1" and have 44100 rate
out. There is a sample conversion like: 

pcm.rate_convert {
	type rate
	slave sl2
}

but how can I attach this rate_convert code to the multi code?

Thanks. 		 	   		  

Re: How to apply rate conversion in asound.conf

[Clemens Ladisch]

Dolevo Jay wrote:
> pcm.!default {
> 	type plug
> 	slave.pcm multi
> }
>
> pcm.multi {
>         slaves.a.pcm "hw:0,1";
>         slaves.b.pcm "hw:1,1";
> ...
>
> My purpose is to apply rate conversion to the "hw:1,1" and have 44100 rate
> out.

All slaves must use the same rate.

The easiest way is apply this to the plug plugin:

pcm.!default {
	type plug
	slave {
		pcm multi
		rate 44100
	}
}


Regards,
Clemens

Re: How to apply rate conversion in asound.conf

[Dolevo Jay]

> Date: Wed, 6 Nov 2013 17:30:25 +0100
> From: clemens@ladisch.de
> To: cmst@live.com; alsa-devel@alsa-project.org
> Subject: Re: [alsa-devel] How to apply rate conversion in asound.conf
> 
> Dolevo Jay wrote:
> > pcm.!default {
> > 	type plug
> > 	slave.pcm multi
> > }
> >
> > pcm.multi {
> >         slaves.a.pcm "hw:0,1";
> >         slaves.b.pcm "hw:1,1";
> > ...
> >
> > My purpose is to apply rate conversion to the "hw:1,1" and have 44100 rate
> > out.
> 
> All slaves must use the same rate.
> 
> The easiest way is apply this to the plug plugin:
> 
> pcm.!default {
> 	type plug
> 	slave {
> 		pcm multi
> 		rate 44100
> 	}
> }
> 
> 
> Regards,
> Clemens
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

Hi,

What you suggested worked perfect but I implemented the rate conversion in my software for some specific reasons.
What I need to do now is to have a aosund.conf which has dmix into multi plugins together. 
So, here is my multi configuration:
--------------------------------
pcm.!default {
	type plug
	slave.pcm multi
}
 
pcm.multi {
        type multi;
        slaves.a.pcm "hw:0,1";
        slaves.a.channels 2;
        slaves.b.pcm "hw:1,1";
        slaves.b.channels 2;
 
        bindings.0.slave a;
        bindings.0.channel 0;
        bindings.1.slave a;
        bindings.1.channel 1;
        bindings.2.slave b;
        bindings.2.channel 0;
        bindings.3.slave b;
        bindings.3.channel 1;
}

--------------------------------
The following dmix runs ok for 1,1 hardware:
--------------------------------
pcm.dmixer {
    type dmix
    ipc_key 2048
    slave {
        pcm "hw:1,1"
    }
    bindings {
        0 0
        1 1
    }
}

pcm.!default {
    type plug
    slave.pcm dmixer
}
--------------------------------

Could you please tell me how I can implement the second configuration with dmixer into the first one which has multi. 
So, basically how can I call a plugin inside of another plugin?

Thanks a lot.

 		 	   		   		 	   		  

Re: How to apply rate conversion in asound.conf

[Dolevo Jay]

> From: cmst@live.com
> To: alsa-devel@alsa-project.org
> Date: Fri, 8 Nov 2013 14:15:30 +0000
> Subject: Re: [alsa-devel] How to apply rate conversion in asound.conf
> 
> 
> 
> 
> 
> > Date: Wed, 6 Nov 2013 17:30:25 +0100
> > From: clemens@ladisch.de
> > To: cmst@live.com; alsa-devel@alsa-project.org
> > Subject: Re: [alsa-devel] How to apply rate conversion in asound.conf
> > 
> > Dolevo Jay wrote:
> > > pcm.!default {
> > > 	type plug
> > > 	slave.pcm multi
> > > }
> > >
> > > pcm.multi {
> > >         slaves.a.pcm "hw:0,1";
> > >         slaves.b.pcm "hw:1,1";
> > > ...
> > >
> > > My purpose is to apply rate conversion to the "hw:1,1" and have 44100 rate
> > > out.
> > 
> > All slaves must use the same rate.
> > 
> > The easiest way is apply this to the plug plugin:
> > 
> > pcm.!default {
> > 	type plug
> > 	slave {
> > 		pcm multi
> > 		rate 44100
> > 	}
> > }
> > 
> > 
> > Regards,
> > Clemens
> > _______________________________________________
> > Alsa-devel mailing list
> > Alsa-devel@alsa-project.org
> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
> 
> Hi,
> 
> What you suggested worked perfect but I implemented the rate conversion in my software for some specific reasons.
> What I need to do now is to have a aosund.conf which has dmix into multi plugins together. 
> So, here is my multi configuration:
> --------------------------------
> pcm.!default {
> 	type plug
> 	slave.pcm multi
> }
>  
> pcm.multi {
>         type multi;
>         slaves.a.pcm "hw:0,1";
>         slaves.a.channels 2;
>         slaves.b.pcm "hw:1,1";
>         slaves.b.channels 2;
>  
>         bindings.0.slave a;
>         bindings.0.channel 0;
>         bindings.1.slave a;
>         bindings.1.channel 1;
>         bindings.2.slave b;
>         bindings.2.channel 0;
>         bindings.3.slave b;
>         bindings.3.channel 1;
> }
> 
> --------------------------------
> The following dmix runs ok for 1,1 hardware:
> --------------------------------
> pcm.dmixer {
>     type dmix
>     ipc_key 2048
>     slave {
>         pcm "hw:1,1"
>     }
>     bindings {
>         0 0
>         1 1
>     }
> }
> 
> pcm.!default {
>     type plug
>     slave.pcm dmixer
> }
> --------------------------------
> 
> Could you please tell me how I can implement the second configuration with dmixer into the first one which has multi. 
> So, basically how can I call a plugin inside of another plugin?
> 
> Thanks a lot.
> 
>  		 	   		   		 	   		  
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel


Hello,

I'd appreciate if someone could tell me even this is possible or not?

Thanks.
 		 	   		  

Re: How to apply rate conversion in asound.conf

[Clemens Ladisch]

Dolevo Jay wrote:
> how can I call a plugin inside of another plugin?

The slave PCM name is the name of some pcm.xxx device.

> What I need to do now is to have a aosund.conf which has dmix into multi plugins together.

pcm.!default {
	type plug
	slave.pcm multi
}

pcm.multi {
	type multi
	slaves {
		a { pcm "hw:0,1" channels 2 }
		b { pcm "dmixer" channels 2 }
	}
	bindings [
		{ slave a channel 0 }
		{ slave a channel 1 }
		{ slave b channel 0 }
		{ slave b channel 1 }
	]
}

pcm.dmixer {
	type dmix
	...
}

But you need another dmix device for hw:0,1.


Regards,
Clemens