aplay-amix utilities on mako

[Dayananda A]

Hi Guys,

    I have been trying to bring up the audio utilities amix and aplay on nexus 4 and I have been having following problems. Have you guys tried it before and do you know how to go about it? The objective is to an audio on an uplink during active call.

I have come to know that we can achieve this as per the discussion over here

http://stackoverflow.com/questions/15204570/inject-uplink-audio-in-call-with-snapdragon-msm8960-soc

running amix has no issues. No errors in the syslog nor on the application side.

I initiated a voice call and started aplay. 

aplay -Dhw:0,0 sample.wav                           

aplay: Playing 'sample.wav':Signed 16 bit Little Endian

Aplay:Failed in pcm_prepare

The logcat gives the error as below

E/alsa_pcm( 2736): cannot prepare channel: errno =-22

dmesg 

soc-audio soc-audio.0: can't get BE for VOICE_PLAYBACK_TX

<3>[  355.800427]  MSM8960 Media1: no BE found for VOICE_PLAYBACK_TX

<3>[  355.808942]  MSM8960 Media1: dpcm: no backend DAIs enabled for MSM8960 Media1

These errors mean that there is no backend available for this. Exact meaning of backend and how we can get it on here is a bit grey to me. 

root@android:/mnt/sdcard #

Attached is the dump of dmesg. Please help.

Regards,

-Daya