On 11/11/2009 05:50 PM, Mads Kiilerich wrote: > http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html#gf13067c0ebde29118ca05af76e5b17a9 > says about snd_pcm_writei: > >> Returns: a positive number of frames actually written otherwise a >> negative error code >> ... >> Return values: >> ... >> -EPIPE an underrun occurred >> ... >> The count of bytes can be less only if a signal or underrun occurred. ... > It surprises me that snd_pcm_writei shows non-blocking behaviour in case > of underruns and don't use all the offered data. I would guess that it > either blocked and enjoyed the data it finally got, or that it gave an > error and didn't take any data at all. But if this is how it is, then > ... that is how it is ;-) Ok, experiments indicates that the documented blocking behaviour only applies in SND_PCM_STATE_RUNNING. snd_pcm_writei apparently behaves non-blocking in SND_PCM_STATE_PREPARED. I can see how that kind of makes sense - I just didn't expect that. Is that correctly understood? /Mads _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
