[alsa-devel] Problems with snd_pcm_wait(..)
Hey,
I tried to implement a callback functionality with ALSA based on the example given at http://www.cs.utk.edu/~vose/linux/equalarea.com/alsa-audio.html#interruptex. Especially the while-loop is basically the same in my program. However, it doesn't work. I can trace the program to snd_pcm_wait(..) which just waits endlessly.
The whole thing is called within a thread. The thread is still accessible from elsewhere in the pogram. It's just the snd_pcm_wait(..)-function which does not return although a time-out of 1000 ms is given.
If I don't wait for the device I get the following assertion: pcm.c:1079: snd_pcm_writei: Assertion `size == 0 || buffer' failed.
Any ideas what could be wrong?
greetings.. ..Markus
On Mon, 11 Jan 2010, Markus Luttenberger wrote:
Hey,
I tried to implement a callback functionality with ALSA based on the example given at http://www.cs.utk.edu/~vose/linux/equalarea.com/alsa-audio.html#interruptex. Especially the while-loop is basically the same in my program. However, it doesn't work. I can trace the program to snd_pcm_wait(..) which just waits endlessly.
Which device you're using? If PulseAudio is in path, there is a bug fixed recently:
https://bugzilla.redhat.com/show_bug.cgi?id=534130
Jaroslav
----- Jaroslav Kysela perex@perex.cz Linux Kernel Sound Maintainer ALSA Project, Red Hat, Inc.
Markus Luttenberger schrieb:
I tried to implement a callback functionality with ALSA based on the example given at http://www.cs.utk.edu/~vose/linux/equalarea.com/alsa-audio.html#interruptex. Especially the while-loop is basically the same in my program. However, it doesn't work. I can trace the program to snd_pcm_wait(..) which just waits endlessly.
Oops, I overlooked something obvious (I set the snd_pcm_sw_params_set_avail_min(..) to the wrong value). Ignore my question, sorry.
greetings.. ..Markus
participants (2)
-
Jaroslav Kysela -
Markus Luttenberger