[linux-audio-dev] Utility for recording audio track with midi clock

[Gerrit Niestijl]

Hi,

A friend of mine owns a Roland vs-1680 harddiskrecorder. It has a
feature that allows for recording and playing back a midi clock signal
alongside the audio tracks. This makes it possible to create a tempo
map with a (hardware) sequencer, record it on the vs-1680, and use it
to keep the sequencer in sync with subsequently recorded audio tracks .

We work together on a project, and i would like to be able to record
and play back the audio mix from the vs-1680 to my computer together
with the midi clock data (he takes his machine home to work on the
audio part). That way i can work on the sequences on my mpc1000, and
play back the audio whith the sequences synced  midi clock slave.

I believe there is currently no linux app that can do that, so i am
considering to try to create a utility for it. But i have little
programming experience and none regarding alsa and jack, so i would
like feedback on my ideas.

My plan is to write a little program that opens 2 midi ports (in and
out) and 2 jack ports (in and out). The program wil monitor the midi
input port for midi clock messages. It will write zero's to the jack
output port but when it recieves a midi clock message it will write a
value of 1 to the jack port. This way i can store the midi clock
signal in a audio file, for example with ecasound. I know, this is
ugly! For playback i would have the program monitor the jack input port and
output a midi clock message when a sample value of 1 passes by.

I hope this explains my plan clear enough. I have looked at the
example programs for alsa and jack and to me it looks like i could
copy and paste something together, that could be my lack of
experience. What do you think? Is this possebly going to work or do i
overlook major difficulties?

Any advice would be very welcome!

-- 
Greetings, Gerrit