https://www.marcelpost.com/wiki/index.php?action=history&feed=atom&title=AlsaAlsa - Revision history2026-05-17T04:57:38ZRevision history for this page on the wikiMediaWiki 1.39.17https://www.marcelpost.com/wiki/index.php?title=Alsa&diff=1249&oldid=prevAdmin at 08:39, 6 November 20132013-11-06T08:39:51Z<p></p>
<p><b>New page</b></p><div>how-to-determine-your-audio-cards-or-usb-mics-maximum-sampling-rate<br />
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<code><br />
arecord -f dat -r 60000 -D hw:0,0 -d 5 test.wav<br />
</code><br />
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---> 48,000Hz<br />
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check volume: <br />
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<code><br />
sox recordedfile.wav -n stat<br />
</code><br />
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near-realtime audio levels:<br />
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<code><br />
arecord -Dhw:0 -c2 -d 0 -fdat /dev/null -vvv<br />
</code><br />
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find out the alsa device id's:<br />
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<code><br />
root@raspberrypi:/home/map# cat /proc/asound/cards<br />
0 [Device ]: USB-Audio - USB Sound Device<br />
USB Sound Device at usb-bcm2708_usb-1.3, full speed<br />
1 [ALSA ]: BRCM bcm2835 ALSbcm2835 ALSA - bcm2835 ALSA<br />
bcm2835 ALSA<br />
</code><br />
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Therefore, the hardware device id for the BRCM device is: $hw:1<br />
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To specify a recording device, first find out which device id is set for the input device:<br />
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<code><br />
root@raspberrypi:/home/map# arecord -l<br />
**** List of CAPTURE Hardware Devices ****<br />
card 0: Device [USB Sound Device], device 0: USB Audio [USB Audio]<br />
Subdevices: 1/1<br />
Subdevice #0: subdevice #0<br />
root@raspberrypi:/home/map#<br />
</code><br />
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Therefore, the alsa hardware device id for the capture device on the USB Sound Device (there is only one) is: $hw:0,0<br />
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==CLI setting of audio parameters==<br />
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The command line can be used to set many values of the sound device. Most options are to set volume, capture device, balance, etc..<br />
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For example, lets say we want to Unmute and then Set the Master Volume.<br />
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First, find out what your sound card device is capable of:<br />
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<code><br />
amixer -L<br />
</code><br />
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Troubleshooting:<br />
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arecord: set_params:1145: Unable to install hw params:<br />
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Seems to be a fault with the usb stack or something silly, a reboot fixed this problem for me.</div>Admin