Paul Davis wrote: > > >Q: with the ice1712 it is possible to run two or more cards in sync > >A: Yes, if you're not thinking to share the same clock chip (i.e. some > >drift is possible). > > My interpretation: two cards will drift. or something. can you be more > clear about what you mean? they will drift if you do use the same > clock chip? or they will drift if you don't? whats a clock chip? is a > word clock signal a "clock chip"?
If two cards does not share the same clock source they may drift, simply. > > >Q: will this be as simple as calling snd_pcm_open for n streams, and > >snd_pcm_link (stream[0]) for streams [1, n - 1]? > >A: Yes. Note however that link is realized "as best as possible" then > >you may have some microseconds between the start/stop of different > >cards. > > but does this have anything to do with multi PCM, and does it do anything > about drift? I cannot parse the former and "No" the latter. > does snd_pcm_link() do the important work in user space or kernel space? Kernel space. > >Q: Does multi PCM run in sync? > >A: Yes, of course. > > so the multi PCM code now handles drift and corrects for it? that > wasn't true some time ago (or so says the mail archive). No, but it could (simply decrementing appl_ptr under the scene on all PCM but the slower). -- Abramo Bagnara mailto:[EMAIL PROTECTED] Opera Unica Phone: +39.546.656023 Via Emilia Interna, 140 48014 Castel Bolognese (RA) - Italy ALSA project http://www.alsa-project.org It sounds good! _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
