Rate Conversion

[Kris Modrak <u9514439@anu.edu.au>]

I am writing a PCM application and wish to play a .wav file that has a
sampling rate of 8kHz on a hardware setup that only supports sampling
frequencies of 44.1 or 48kHz.

Does anyone know how to implement this?

I have tried setting up a rate plugin in my .asoundrc file

pcm.r8 {
        type rate               # Rate PCM
        slave slave_rate8000Hz  # Slave name
}

pcm_slave.slave_rate8000Hz {
        pcm "hw:0,0"
        rate 8000
}

But when using this device I am unable to set the rate to 8000 using
snd_pcm_hw_params_set_rate_near ();

I tried using the r8 device with aplay (version 0.9.0beta12) and get the
following error

> aplay -Dr8 s1.wav
Playing WAVE 's1.wav' : Signed 16 bit Little Endian, Rate 8000 Hz, Mono
aplay: set_params:717: Broken configuration for this PCM: no
configurations available

I know it is possible to play the file because it works when I play it
from a netscape window.

Thanks in advance
Kris Modrak


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