Audio_alsa_sink question


#1

Hi

I have a problem with the audio sink. I’m playing around with the
analysis_filterbank block. I have a GUI allowing the user to pick a
channel. That channel then gets connected to an FM demodulator,volume
control and finally an audio sink. At the start of the app, I
initialise everything and the audio sink works. As soon as I change a
channel by reconnecting everything, I get this error:

audio_alsa_sink[plughw:0,0]: snd_pcm_hw_params failed: File descriptor
in bad state
terminate called after throwing an instance of ‘std::runtime_error’
what(): check topology failed on audio_alsa_sink(8) using
ninputs=1, noutputs=0
Aborted

Can someone please tell me what might be wrong?

Thanks.

Sebastiaan


#2

On Thu, Jan 15, 2009 at 01:52:08PM +0200, Sebastiaan H. wrote:

in bad state
terminate called after throwing an instance of ‘std::runtime_error’
what(): check topology failed on audio_alsa_sink(8) using
ninputs=1, noutputs=0
Aborted

Can someone please tell me what might be wrong?

Thanks.
Sebastiaan

That’s a bug in the implementation of gr-audio-alsa.
If you look in the code you’ll find a couple of FIXMEs.
One of those is the thing you’ve stumbled on to.

Eric