Uli Franke wrote:
I set the hw params sample rate to 44k1 without error, but a subsequent call of snd_pcm_start returns EPIPE.
In theory, this error code is returned if you didn't write any samples into the buffer before starting.
T(snd_pcm_start(pcm));
n = snd_pcm_writei(pcm, buffer, ARRAY_SIZE(buffer) / channels);
And indeed this code tries to start the device without any samples in the buffer.
When setting hw params sample rate to 4k this does not happen.
This appears to be an artifact of the resampler.
When I write samples before starting the stream, snd_pcm_start returns
File descriptor in bad state (-77)
which is obvious as the state of the stream changes from PREPARED to RUNNING.
To prevent the device from starting automatically, change the start_threshold.
Regards, Clemens