9 Dec
2005
9 Dec
'05
9:52 p.m.
Hi,
I'm trying to figure out how to build an ALSA MIDI sequencer that'll
sync with other sequencers. I've looked around but didn't see any
recent information. (The closest hits were a five-year-old page of
Takashi Iwai's, a three-year-old LAD thread with the subject line
"MIDI sync and ALSA sequencer", and a LAU thread from last year,
none of which sounded entirely encouraging.)
So, my question is, what's the recommended way of synchronizing two
MIDI sequencers these days, using ALSA? Is there any protocol (MTC,
MMC...) that you would recommend so as to be compatible with a large
number of other software packages? Any hints would be appreciated.
Pointers to sample implementations of MIDI sync with ALSA would be
great.
Best,
Peter
12 Dec
12 Dec
4:23 p.m.
On Sat, Dec 10, 2005 at 02:52:15AM +0100, Peter Brinkmann wrote:
Hi,
I'm trying to figure out how to build an ALSA MIDI sequencer that'll
sync with other sequencers. I've looked around but didn't see any
recent information. (The closest hits were a five-year-old page of
Takashi Iwai's, a three-year-old LAD thread with the subject line
"MIDI sync and ALSA sequencer", and a LAU thread from last year,
none of which sounded entirely encouraging.)
So, my question is, what's the recommended way of synchronizing two
MIDI sequencers these days, using ALSA? Is there any protocol (MTC,
MMC...) that you would recommend so as to be compatible with a large
number of other software packages? Any hints would be appreciated.
Pointers to sample implementations of MIDI sync with ALSA would be
great.
hello,
imho a simple way to synchonize 2 (or more) midi sequencers is to use
the midi start, stop and clock messages (status codes 0xfa, 0xfc, 0xf8)
i've successfuly used this approcach to synchronize a software
sequencer (midish) to a hardware (external) one. I also could
synchonize multiple instances of midish to each other.
i dont know how to implement this specificaly with the alsa api, since
i used the raw midi devices /dev/midiXX; you can check the source of
midish (http://caoua.org/midish/midish-0.2.2.tar.gz, see mux.c).
this approch should be compatible with most software or hardware
midi sequencers.
regards,
--
Alexandre
13 Dec
13 Dec
5:03 a.m.
Peter Brinkmann wrote:
I'm trying to figure out how to build an ALSA MIDI
sequencer that'll
sync with other sequencers. I've looked around but didn't see any
recent information.
So, my question is, what's the recommended way of synchronizing two
MIDI sequencers these days, using ALSA? Is there any protocol (MTC,
MMC...) that you would recommend so as to be compatible with a large
number of other software packages?
ALSA itself doesn't support any synchronization protocol; the only
possible timer source is some hardware timer interrupt.
It is possible to adjust the queue tempo relative to the timer
interrupt frequency with snd_seq_queue_tempo_set_skew().
Pointers to sample implementations of MIDI sync with
ALSA would be
great.
AFAICS Ardour supports MTC.
HTH
Clemens
14 Dec
14 Dec
7:51 p.m.
Clemens, Alexandre,
Thanks for your replies!
ALSA itself doesn't support any synchronization
protocol; the only
possible timer source is some hardware timer interrupt.
Ah, that would explain the
lack of documented sync features;) Are there
any plans to implement any sync protocols in ALSA? This seems like a
fairly significant omission.
Best,
Peter
6916
days inactive
6921
days old
linux-audio-dev@lists.linuxaudio.org
3 comments
3 participants
participants (3)
-
Alexandre Ratchov -
Clemens Ladisch -
Peter Brinkmann