Dear Clemens,

Thanks a lot for your inputs w.r.t the below issue, Now I tried playing 48Khz mono that works fine,

Could you please clarify the following points

1) CPU consumption is 18%, with above asound.conf & the app alsa_loopback_min_mono.c for establishing my GSM two way call (ie., VINR to VOUTR & VINL to VOUTL) , this is very huge & I want to reduce this CPU consumption drastically, Is there any other ways in alsa where I can do this two way GSM call (ie., VINR to VOUTR & VINL to VOUTL) without using alsa_loopback_min_mono.c application

Could you please let me know if there is anything that can be done in using alsa plugins in order to reduce CPU consumption???

2) And am hearing echo, when I do GSM calls when using the above attachd asound.conf & the app alsa_loopback_min_mono.c, could you please help me out is there any options to do echo cancellation in alsa??

3)Am trying to completely understand the above attched asound.conf, but am not still very clear w.r.t the understanding of bindings in alsa plugins as am confused, Could you please clarify the doubt that

i) Does the below lines correspond to VINL to VOUTL or VINL to VOUTR??

bindings { 0 1 }

ii) & similarly does the below lines correspond VINL to VOUTL??

bindings { 0 0 }

iii) similarly does the correspond VINL to VOUTL??

bindings.0 0

iv) similarly does the correspond VINL to VOUTR or VINR to VOUTR??

bindings.0 1

Kindly do the needful as early as possible, as only this is pending from my side w.r.t AUDIO in my project

Once again really appreciate & Thanks a lot for your prompt responses

Many Many Thanks in advance again,

________________________________________ From: Clemens Ladisch clemens@ladisch.de Sent: Tuesday, March 10, 2015 4:20 PM To: Srinivasan S Cc: alsa-devel@alsa-project.org; linux-audio-dev@lists.linuxaudio.org Subject: Re: Fw: [alsa-devel] Using loopback card to Connect GSM two way call to the real sound card UDA1345TS

Srinivasan S wrote:

$ aplay -f dat -D VOUTL new.wav Playing WAVE 'new.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo aplay: set_params:1087: Channels count non available

You are trying to play a two-channel file on a single-channel device.

Regards, Clemens

Could you please provide any inputs w.r.t the below queries

Am awaiting for your suggestions from past 2 to 3 days

Thanks, Srinivasan S ________________________________________ From: Srinivasan S Sent: Monday, March 30, 2015 5:10 PM To: clemens@ladisch.de Cc: alsa-devel@alsa-project.org; linux-audio-dev@lists.linuxaudio.org Subject: Fw: Fw: [alsa-devel] Using loopback card to Connect GSM two way call to the real sound card UDA1345TS

Dear Clemens

Could you please provide any inputs w.r.t the below queries

Kindly do the needful as early as possible

Many Thanks in Advance,

________________________________________ From: Srinivasan S Sent: Saturday, March 28, 2015 8:13 AM To: Clemens Ladisch Cc: alsa-devel@alsa-project.org; linux-audio-dev@lists.linuxaudio.org Subject: Re: Fw: [alsa-devel] Using loopback card to Connect GSM two way call to the real sound card UDA1345TS

Dear Clemens,

Thanks a lot for your inputs w.r.t the below issue, Now I tried playing 48Khz mono that works fine,

Could you please clarify the following points

1) CPU consumption is 18%, with above asound.conf & the app alsa_loopback_min_mono.c for establishing my GSM two way call (ie., VINR to VOUTR & VINL to VOUTL) , this is very huge & I want to reduce this CPU consumption drastically, Is there any other ways in alsa where I can do this two way GSM call (ie., VINR to VOUTR & VINL to VOUTL) without using alsa_loopback_min_mono.c application

Could you please let me know if there is anything that can be done in using alsa plugins in order to reduce CPU consumption???

2) And am hearing echo, when I do GSM calls when using the above attachd asound.conf & the app alsa_loopback_min_mono.c, could you please help me out is there any options to do echo cancellation in alsa??

3)Am trying to completely understand the above attched asound.conf, but am not still very clear w.r.t the understanding of bindings in alsa plugins as am confused, Could you please clarify the doubt that

i) Does the below lines correspond to VINL to VOUTL or VINL to VOUTR??

bindings { 0 1 }

ii) & similarly does the below lines correspond VINL to VOUTL??

bindings { 0 0 }

iii) similarly does the correspond VINL to VOUTL??

bindings.0 0

iv) similarly does the correspond VINL to VOUTR or VINR to VOUTR??

bindings.0 1

Kindly do the needful as early as possible, as only this is pending from my side w.r.t AUDIO in my project

Once again really appreciate & Thanks a lot for your prompt responses

Many Many Thanks in advance again,

________________________________________ From: Clemens Ladisch clemens@ladisch.de Sent: Tuesday, March 10, 2015 4:20 PM To: Srinivasan S Cc: alsa-devel@alsa-project.org; linux-audio-dev@lists.linuxaudio.org Subject: Re: Fw: [alsa-devel] Using loopback card to Connect GSM two way call to the real sound card UDA1345TS

Srinivasan S wrote:

$ aplay -f dat -D VOUTL new.wav Playing WAVE 'new.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo aplay: set_params:1087: Channels count non available

You are trying to play a two-channel file on a single-channel device.

Regards, Clemens

Thanks a lot for your Prompt responses Clemens

Extremely sorry for my poor understanding,

Could you please clarify the following

1. As per your suggestions below, I didn't understand what is 'two channel devices' does this means do we need to have to real hardware sound card's (ie., two different audio codecs)??? whereas as of now am using only one audio codec( ie., UDA1345TS), if not could you please help me out how to use two channel devices using alsa api's in application or any references for the same???

2. Regarding bindings as you explained"bindings.x y" or "bindings { x y }" maps channel x of this device to channel y of the slave device.

I didn't understand channel x of this device means is it the real sound card??? which is the current device ie., channel x of this device means???

I didn't understand channel y of the slave device means??.. ie., which is slave device here????

Kindly do the needful as early as possible

Awaiting for your replies

Many Thanks in advance ________________________________________ From: Clemens Ladisch clemens@ladisch.de Sent: Thursday, April 2, 2015 3:13 PM To: Srinivasan S Cc: alsa-devel@alsa-project.org; linux-audio-dev@lists.linuxaudio.org Subject: Re: [alsa-devel] Fw: Using loopback card to Connect GSM two way call to the real sound card UDA1345TS

Srinivasan S wrote:

CPU consumption is 18%, with above asound.conf & the app alsa_loopback_min_mono.c for establishing my GSM two way call (ie., VINR to VOUTR & VINL to VOUTL) , this is very huge & I want to reduce this CPU consumption drastically, Is there any other ways in alsa where I can do this two way GSM call (ie., VINR to VOUTR & VINL to VOUTL) without using alsa_loopback_min_mono.c application

dmix needs more CPU than dshare because it needs to mix multiple streams together; if possible, use dshare instead of dmix.

dshare needs more CPU than direct access to the device because the data needs to be copied and reformatted. dshare is needed only when the application(s) cannot handle the format of the actual device; if possible, change your application to handle the two-channel devices.

And am hearing echo, when I do GSM calls when using the above attachd asound.conf & the app alsa_loopback_min_mono.c, could you please help me out is there any options to do echo cancellation in alsa?

ALSA has not built-in echo cancellation. You have to implement this yourself, or use some third-party library.

If dmix/dshare alone eats 18 % CPU, it is unlikely that this is feasible without hardware support.

Am trying to completely understand the above attched asound.conf, but am not still very clear w.r.t the understanding of bindings

"bindings.x y" or "bindings { x y }" maps channel x of this device to channel y of the slave device.

Regards, Clemens

Dear Clemens,

Thanks a lot for your information, It is really understandable for a newbie like me

As you suggested, could you please provide me some sample application links without using dshare plugin , ie., using the two channels ie., left & right directly

So that I can reduce the CPU consumption drastically

Thanks a lot for your prompt support w.r.t this thread once again

Kindly do the needful as early as possible

Many Thanks in advance again

________________________________________ From: Clemens Ladisch clemens@ladisch.de Sent: Thursday, April 2, 2015 8:38 PM To: Srinivasan S Cc: alsa-devel@alsa-project.org; linux-audio-dev@lists.linuxaudio.org Subject: Re: [alsa-devel] Fw: Using loopback card to Connect GSM two way call to the real sound card UDA1345TS

Srinivasan S wrote:

I didn't understand what is 'two channel devices' does

The two channels are "left" and "right".

Regarding bindings as you explained"bindings.x y" or "bindings { x y }" maps channel x of this device to channel y of the slave device.

I didn't understand channel x of this device means is it the real sound card??? which is the current device ie., channel x of this device means???

I didn't understand channel y of the slave device means??.. ie., which is slave device here????

"This device" is the virtual device that is defined. The slave device is the device whose name is specified with "slave.pcm".

Regards, Clemens

Dear Clemens,

Could you please provide any inputs or suggestions w.r.t the below query

Kindly do the needful as early as possible,

Many Thanks in advance, ________________________________________ From: alsa-devel-bounces@alsa-project.org alsa-devel-bounces@alsa-project.org on behalf of Srinivasan S srinivasan.s@tataelxsi.co.in Sent: Wednesday, April 22, 2015 11:41 AM To: Clemens Ladisch Cc: alsa-devel@alsa-project.org; linux-audio-dev@lists.linuxaudio.org Subject: Re: [alsa-devel] Fw: Using loopback card to Connect GSM two way call to the real sound card UDA1345TS

Dear Clemens,

Thanks a lot for your information, It is really understandable for a newbie like me

As you suggested, could you please provide me some sample application links without using dshare plugin , ie., using the two channels ie., left & right directly

So that I can reduce the CPU consumption drastically

Thanks a lot for your prompt support w.r.t this thread once again

Kindly do the needful as early as possible

Many Thanks in advance again

________________________________________ From: Clemens Ladisch clemens@ladisch.de Sent: Thursday, April 2, 2015 8:38 PM To: Srinivasan S Cc: alsa-devel@alsa-project.org; linux-audio-dev@lists.linuxaudio.org Subject: Re: [alsa-devel] Fw: Using loopback card to Connect GSM two way call to the real sound card UDA1345TS

Srinivasan S wrote:

I didn't understand what is 'two channel devices' does

The two channels are "left" and "right".

Regarding bindings as you explained"bindings.x y" or "bindings { x y }" maps channel x of this device to channel y of the slave device.

I didn't understand channel x of this device means is it the real sound card??? which is the current device ie., channel x of this device means???

I didn't understand channel y of the slave device means??.. ie., which is slave device here????

"This device" is the virtual device that is defined. The slave device is the device whose name is specified with "slave.pcm".

Regards, Clemens _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

Thanks a lot for your quick responses Clemens,

Sorry for my poor understanding

As am newbie to alsa, due to time constraints am unable to spend time in writing my own application

As per your suggestion, did you mean that , If I use Jack plugin , does it resolve this problem (ie., does the CPU consumption reduce drastically instead of dshare)

Kindly do the needful

Once again Thanks a lot for your suggestions Clemens w.r.t this Thread

Thanks in advance, Srinivasan S

________________________________________ From: Clemens Ladisch clemens@ladisch.de Sent: Friday, April 24, 2015 1:36 PM To: Srinivasan S Cc: alsa-devel@alsa-project.org; linux-audio-dev@lists.linuxaudio.org Subject: Re: [alsa-devel] Fw: Using loopback card to Connect GSM two way call to the real sound card UDA1345TS

Srinivasan S wrote:

could you please provide me some sample application links without using dshare plugin , ie., using the two channels ie., left & right directly

I am not aware of any (sample) program that does something like this (except maybe Jack, but floating-point samples would not be appropriate for your application).

You have to implement this yourself.

Regards, Clemens

Dear Clemens,

As you suggested am using jack plugin, but am facing the below error

etc/asound.conf

pcm.!default { type plug slave { pcm "jack" } }

pcm.jack { type jack playback_ports { 0 alsa_pcm:playback_1 1 alsa_pcm:playback_2 } capture_ports { 0 alsa_pcm:capture_1 1 alsa_pcm:capture_2 } }

ctl.mixer0 { type hw card 0 }

root@am335x-evm:/# aplay -D pcm.jack TangoForTajMusic11.wav ALSA lib /home/jenkins/amsdk-nightly-build/build-CORTEX_1/arago-tmp-external-linaro-toolchain/work/cortexa8t2hf-vfp-neon-oe-linux-gnueabi/alsa-lib/1.0.27.2-r0/alsa-lib-1.0.27.2/src/pcm/pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM pcm.jack aplay: main:722: audio open error: No such file or directory root@am335x-evm:/#

Pls find the details of the architecture as below:

what ever the GSM analog audio out data is pumped as VINR to stereo codec & the output of the stereo codec ie., VOUTR is pumped to the Speaker of the custom board

what ever the GSM analog audio out data is pumped as VINR to stereo codec & the output of the stereo codec ie., VOUTR is pumped to the Speaker of the custom board GSM MIC-> VINR -> stereo codec->VOUTR -> board speaker

what ever the board MIC data is pumped as VINL to stereo codec & the output of the stereo codec ie., VOUTL is pumped as analog input to the GSM Speaker Board Mic -> VINL-> stereo codec -> VOUTL ->GSM speaker

Pls let me know if any other details is required from my side

Kindly do the needful as early as possible Awaiting for your suggestions

________________________________________ From: Clemens Ladisch clemens@ladisch.de Sent: Friday, April 24, 2015 6:15 PM To: Srinivasan S Cc: alsa-devel@alsa-project.org; linux-audio-dev@lists.linuxaudio.org Subject: Re: [alsa-devel] Fw: Using loopback card to Connect GSM two way call to the real sound card UDA1345TS

Srinivasan S wrote:

did you mean that , If I use Jack plugin , does it resolve this problem (ie., does the CPU consumption reduce drastically instead of dshare)

It is unlikely that running your two programs on top of Jack will use less CPU than with dshare. However, I don't know the details of your architecture, so the only way to find out would be for you to try it.

Regards, Clemens

Srinivasan S wrote:

2. Could you please let me know, I have downloaded jack-1.9.10.tar.bz2, how this needs to be installed in my rootfs

IIRC Jack uses some non-standard build system. Try asking on the Jack mailing list how to cross-compile it.

Please note that the ALSA Jack plugin is part of the alsa-plugins package.

And as I already mentioned, it is unlikely that Jack will use less CPU than dshare.

Regards, Clemens