[alsa-devel] Source of timing for MIDI and/or audio synchronization

Dmitry Baikov dsbaikov at gmail.com
Tue Jun 12 14:23:40 CEST 2007


Hi Mark,

On 6/12/07, Mark Rivera <marr at lumin.us> wrote:
> I designed and built a MIDI sequencer based around a Microchip PIC18
> MCU, and used the built-in hardware timers and interrupt levels to drive
> the 'scheduler' for initiating MIDI output (EUSART) routines. In this
> same vein, I would like to write a software sequencer with as 'tight'
> timing as possible.
Man, join linux-audio-dev list, you'll be our god :)

> So, in a similar concept for Linux - from where does
> the timing of audio and MIDI events come from?
> It occurred to me that it would be nice to have a loadable kernel module
> (LKM) to which userland programs could subscribe for receiving 'soft
> interrupts' based on some timer (cpu ticks?) so that various software
It think you should look into hpet/rtc devices.

You also may be interested in jack and especially midi-over-jack
(which I, in fact, maintain).
It is an audio-sample-syncronous midi transport.
You may look into my jackmidi-driver for details about event timing.
I even hope you can help to make better :)

And I'm also very interested in writing a good sequencer.

Regards,
Dmitry.


More information about the Alsa-devel mailing list