At Tue, 20 Nov 2007 16:54:32 +0200, Heikki Lindholm wrote: > > 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? Hmm, at the second look at the dmix/dsnoop code, it has some lines that actually update the timestamp value (as emulation). So, basically it should work. Maybe some other parts are broken... Do you have a small test case code just for checking? thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
