Takashi Iwai kirjoitti: > At Mon, 19 Nov 2007 15:41:46 +0200, > Heikki Lindholm wrote: >> Jaroslav Kysela kirjoitti: >>> On Mon, 19 Nov 2007, Heikki Lindholm wrote: >>> >>>> Heikki Lindholm kirjoitti: >>>>> Hello list, >>>>> >>>>> I took up some old dusty code of mine that uses snd_pcm_state followed >>>>> by snd_pcm_status_get_tstamp when in capture mode. The code used to >>>>> work, but now the returned timestamps are all zeroes. Is there some API >>>>> change done recently or is the whole timestamping deprecated or >>>>> something? I've tried with different drivers on ubuntu's alsa .14 and >>>>> gentoo's .14. I've also tried mmap'ed and r/w modes, and I'm setting the >>>>> TSTAMP_MMAP sw param. >>>> I figured out that this doesn't happen when using hw:x,y devices. Is it >>>> a documented feature that some (software?) devices don't fill in timestamps? >>> I think that it should be fixed. Could you send us 'snd_pcm_dump()' for a >>> non-working device? It's probably ommited code in direct pcm plugins (dmix >>> & etc.). >> Here goes. The driver is snd_aoa. It seems as if the timestamp mode >> isn't propagated to the hw device. > > AFAIK, the time-stamp mode isn't handled properly with direct plugins > because of its nature. Since the direct plugins share the same PCM > hardware instance with multiple processes, you cannot change the > parameter arbitrarily from a single client. > > We may implement an emulation in alsa-lib instead, though... For the time being, is there any other way of determining whether a pcm supports time stamps than just trying out and seeing if zero is all that comes out? -- Heikki Lindholm _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
