PiSound Support for 16kHz

Pisound Projects
1

Hello,

I am trying to use RTAudio with the PiSound. I currently have a real time kernel and everything seems to be working fine except because of certain constraints in my upstream pipeline, I can only support real time applications upto 16kHz. I should mention that I am playing audio through the line out. Since my target application involves speech that sampling rate is acceptable to me. However, I do not see official support for 16kHz listed in the documentation and was wondering if there was a configuration option to enable that or whether it is not officially supported but something I could get working. Additionally, I was wondering if it would be possible to use the line in at a different rate like 48kHz while the line out runs at 16kHz.

Thank you!

2

You must use one of 48kHz, 96kHz or 192kHz rates when interacting with the Pisound hardware. If you need a custom rate like 16kHz, you can upsample to 48kHz in software, as it’s a multiple of 16kHz it should be straightforward.

3

We are working on an audio streaming project which because of network jitter cannot deliver packets consistently at the 48k required. So we decided to decimate the incoming signal and playback at 16k. I guess we will figure out if we can make any improvements to the jitter over the network first. Thank you!

4

Yes, that’s what I meant - internally you should downsample to 16kHz for your purposes, but use 48kHz rate when interacting with Pisound.