Gabriel Oprea

Recording an audio file using ALSA arecord

Discussion created by Gabriel Oprea on Mar 22, 2012
Latest reply on Jan 24, 2013 by PeterChan

Hi,

I'm trying to test the audio part of i.MX28 evk board.

I've build and installed ALSA-lib and ALSA-utils. After booting up the board I'm trying to record some audio from mic to a file and then play it to speakers.

For recording I'm using alsa "arecord" :
arecord -D "hw:0,0" -t wav -c 2 -r 48000 -f S16_LE foo1.wav

For playing I'm using alsa "aplay":
aplay foo1.wav

The file is created by arecord but when i try to play it I dont hear a thing.

arecord -l show me:
**** List of CAPTURE Hardware Devices ****
card 0: mxsevk [mxs-evk], device 0: SGTL5000 SGTL5000-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0

aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: mxsevk [mxs-evk], device 0: SGTL5000 SGTL5000-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: mxsevk_1 [mxs-evk], device 0: MXS SPDIF mxs spdif-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0

Also amixer:

root@freescale ~$ amixer
.............................
Simple mixer control 'Capture',0
Capabilities: cvolume
Capture channels: Front Left - Front Right
Limits: Capture 0 - 15
Front Left: Capture 15 [100%]
Front Right: Capture 15 [100%]
Simple mixer control 'Capture Vol Reduction',0
Capabilities: enum
Items: 'No Change' 'Reduced by 6dB'
Item0: 'No Change'
Simple mixer control 'ADC Mux',0
Capabilities: enum
Items: 'MIC_IN' 'LINE_IN'
Item0: 'MIC_IN'
Simple mixer control 'DAC Mux',0
Capabilities: enum
Items: 'DAC' 'LINE_IN'
Item0: 'DAC'
.......
I've tried to change 'ADC mux' to LINE_IN but still no luck.

When I'm playing an external .wav all works ok and I can hear it with high quality.

Can anyone help me?

Thanks,
Gabriel Oprea

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