Native 16kHz sampling rate.

Moderator: flatmax

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bolom
Posts: 4
Joined: Mon Jul 17, 2017 2:07 pm

Native 16kHz sampling rate.

Post by bolom » Fri Aug 04, 2017 5:09 am

Hi Matt,

Would it be possible to add native 16kHz sampling rate?
I am processing speech, most speech applications run at 8kHz and 16kHz.

Great product!

Thanks
bolom

bolom
Posts: 4
Joined: Mon Jul 17, 2017 2:07 pm

Re: Native 16kHz sampling rate.

Post by bolom » Thu Aug 24, 2017 6:27 am

Hi,

Is 16kHz supported native?

According to file linux/sound/soc/bcm/audioinjector-pi-soundcard.c the constraint table does include 16000, but when I try to record a 16k it defaults to 8k, like this,

pi@raspberrypi:~ $ arecord -Dhw:0,0 -c2 -r16000 -fS16_LE test.wav
Recording WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 16000 Hz, Stereo
Warning: rate is not accurate (requested = 16000Hz, got = 8000Hz)
please, try the plug plugin
^CAborted by signal Interrupt...
pi@raspberrypi:~ $

Thanks

flatmax
Posts: 609
Joined: Sat Jul 23, 2016 11:39 pm

Re: Native 16kHz sampling rate.

Post by flatmax » Fri Aug 25, 2017 9:34 pm

Hi,

The card supports the rates listed at the top of this file :
https://github.com/raspberrypi/linux/bl ... oundcard.c

Hmmm ... not sure why it doesn't work. With the latest kernel I can't record at 8000 Hz ... although an downdate made it work again ... by rolling back my kernel to version 4.9.14 :

Code: Select all

 sudo rpi-update b30461d2621e71eb9b8845b38738af177b9181ed
I tried downdating to kernel 4.4.33 :

Code: Select all

sudo rpi-update 3ffa1c624ae8b5f02a6aac764d407e8d3b5a09bb
Seems not to work at any of these kernels.

I have submitted an issue with the rpi kernel on this topic :
https://github.com/raspberrypi/linux/issues/2176

Matt
Check out our audiophile quality crossovers : https://bit.ly/2kb1nzZ
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Amr
Posts: 1
Joined: Wed Oct 11, 2017 11:27 am

Re: Native 16kHz sampling rate.

Post by Amr » Wed Oct 11, 2017 11:30 am

Dear Matt;

I am also trying to record at sample rate of 8000 Hz, but it is not working. Any updates regarding this issue?

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