Clemens Ladisch wrote:
$ aplay -r 256 test.wav Playing WAVE 'test.wav' : Unsigned 8 bit, Rate 256000 Hz, Mono Warning: rate is not accurate (requested = 256000Hz, got = 192000Hz)
The automatic sample rate converter never uses a frequency higher than 192 kHz.
This maximum frequency is defined in alsa-lib/include/pcm_plugin.h, but you cannot change it without changing LINEAR_DIV and the algorithm in alsa-lib/src/pcm_pcm_rate_linear.c.
Try resampling the .wav file before with sox.
This works. Likewise, playing with "/usr/bin/play" from the sox toolkit also works fine.
It seems that the only limiting going on is during playback, so I'm not terribly worried by this, as we're going to be looking at and processing these samples, not trying to listen to them. Humans can't hear above 20kHz anyway, right?
Thanks to everyone for their help on this.
Cameron.