[alsa-devel] No stream timing info with alsa pulse plugin?

[Takashi Iwai]

On Thu, 24 Sep 2015 07:55:34 +0200,
Arun Raghavan wrote:
> 
> On 3 February 2015 at 07:10, Raymond Yau <superquad.vortex2 at gmail.com> wrote:
> > 2015-1-27 上午3:33 於 "sqweek" <sqweek at gmail.com> 寫道：
> >>
> >> Hi guys,
> >>
> >> I discovered on my machine that alsa_snd_pcm_status_get_tstamp (and
> >> also get_htstamp) stop working when my asoundrc invokes the pulse
> >> plugin.
> >>
> >> That is, normally they work fine but once the sound is going via pulse
> >> the returned time stamp is always zero. I'm trying to understand why
> >> that is.
> >>
> >> I couldn't really find any discussion of the pulse plugin on the
> >> archives so I'm not entirely sure I've found the right list; I was
> >> directed here via the pulseaudio bugzilla[1].
> >>
> >> [1] https://bugs.freedesktop.org/show_bug.cgi?id=88503
> >>
> >
> > http://git.alsa-project.org/?p=alsa-lib.git;a=commitdiff;h=65ff6fdafb705b5e2e6d4b9a94a80e5de89f5de1;hp=9b716075de4f2f7f15e428ee7efaa8960ef45b9c#patch14
> > 448,7 +448,7 @@ static int snd_pcm_ioplug_start(snd_pcm_t *pcm)
> >         if (err < 0)
> >                 return err;
> >
> > -       gettimestamp(&io->trigger_tstamp, pcm->monotonic);
> > +       gettimestamp(&io->trigger_tstamp, pcm->tstamp_type);
> >         io->data->state = SND_PCM_STATE_RUNNING;
> >
> >         return 0;
> > @@ -463,7 +463,7 @@ static int snd_pcm_ioplug_drop(snd_pcm_t *pcm)
> >
> >         io->data->callback->stop(io->data);
> >
> > -       gettimestamp(&io->trigger_tstamp, pcm->monotonic);
> > +       gettimestamp(&io->trigger_tstamp, pcm->tstamp_type);
> >         io->data->state = SND_PCM_STATE_SETUP;
> >
> >         return 0;
> > @@ -1069,7 +1069,10 @@ int snd_pcm_ioplug_reinit_status(snd_pcm_ioplug_t
> > *ioplug)
> > {
> >         ioplug->pcm->poll_fd = ioplug->poll_fd;
> >         ioplug->pcm->poll_events = ioplug->poll_events;
> > -       ioplug->pcm->monotonic = (ioplug->flags &
> > SND_PCM_IOPLUG_FLAG_MONOTONIC) != 0;
> > +       if (ioplug->flags & SND_PCM_IOPLUG_FLAG_MONOTONIC)
> > +               ioplug->pcm->tstamp_type = SND_PCM_TSTAMP_TYPE_MONOTONIC;
> > +       else
> > +               ioplug->pcm->tstamp_type = SND_PCM_TSTAMP_TYPE_GETTIMEOFDAY;
> >         ioplug->pcm->mmap_rw = ioplug->mmap_rw;
> >         return 0;
> > }
> >
> > Although time stamp was enabled in pcm_ioplug.c , it does not implies all
> > those io plugin really support time stamp
> >
> > Is this a bug ?
> 
> Seems to be. Takashi, others -- do have suggestions on how to handle this?

The timestamp isn't supported on ioplug at all.  Only the trigger
timestamp is updated, so far.


Takashi