Takashi Iwai wrote: >At Mon, 19 Aug 2002 17:42:07 +0200 (CEST), >Tim Goetze wrote: >> >> Takashi Iwai wrote: >> >> >At Mon, 19 Aug 2002 09:22:10 +0200 (CEST), >> >Tim Goetze wrote: >> >> >> >> Is it possible to register a sequencer client that acts as a timer >> >> (not only an event consumer/producer), and if so, how would one go >> >> about implementing one? >> > >> >timer = event producer in a certain schedule, isn't it ?? >> >it will deliver "tick" events in a programmed rythm. >> >> You mean it is sufficient to emit SND_SEQ_EVENT_SETPOS_TICK or *_TIME >> periodically, and transport control events accordingly? Are these >> events then used by alsa-lib to update the queue timing information? > >well, sorry, then i misunderstood your question. > >do you mean that a sequencer client as a timer source, or as a >controller of the queue? > >the former is difficult, because the queue is driven by interrupts >from a timer source. that is, a sequencer client must give signals at >the constant and fine period. this is not a job what a user process >does. > >the latter, controlling a queue, would be feasible. >in this case, you can change the tempo or time skew dynamically by >sending events via system-timer port (0:0) to a specified queue. >but anyway, a queue must run individually from the client. > >maybe i can give more specific answer if i understand your question >more clearly...
OK, here goes. I have a core here that processes MIDI and PCM. There's a RTC thread that controls event timing, synced to the sample clock. So, internally, the application has a precise idea of the current tempo, tick, time and frame. Currently, events sent to ALSA sequencer ports are sent via snd_seq_event_output_direct(), with a 0 timestamp. Now what I'm looking for is a way to export this timer functionality to the sequencer system, ie make it possible for other clients to sync to this clock. tim ------------------------------------------------------- This sf.net email is sponsored by: OSDN - Tired of that same old cell phone? Get a new here for FREE! https://www.inphonic.com/r.asp?r=sourceforge1&refcode1=vs3390 _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
