Trigger recording by sending a signal to a track

Hi everyone
I am just wondering if I connected a multi channel
USB interface to Ardour, set for example 8 inputs
to 8 channels and arm them all,
is there any way I could for example send
a signal into input 9 of the interface which would
have its own track in Ardour, and have that signal
start the recording process for the other 8 channels
I set up earlier.

Basically I want to use an aux send on an external
mixer to send a signal into Ardour, and for that signal
to start the recording process, when the process starts
the signal can be cut / shut down yet the recording proceed,
or I can leave the signal alone as it wont be recorded.
The signal has to be an audio one, such as play a track
into the No 9 Channel to trigger the recording of the other
8 tracks.

Thanks for looking in, I look forward to hearing if this
is at all possible.

Kind Regards to all

Sounds like a job for a lua script possibly. Not completely sure but I suspect this could be accomplished with one.


Hi seablade, thank you for commenting
I wish I knew, I was hoping there would be a plug-in / VST that
may accomplish this.
If this can be made work, I can use any digital rack mixer to provide
FOH sound, these are either hard wired to a computer or controlled
over Wi Fi, I could simply play a sound ot of the mixer which would be
connected to a Laptop on the stage, this sound would enter the DAW
via a set channel, and trigger the other pre set 8 /10 or 16 chanels
set up and armed in the DAW, it does not have to be perfect control
as in stopping the recording, this can be done manually, but starting it
from the same application that I sit with in the audience would be of
great benefit, though am guessing that if there is a script to start recording
it would be simple enough to also stop it.

I hope someone can advise

You can’t do this from a plugin, because plugins do not have a way to change the host state (not in any DAW). This requires something that can change the host state, and in Ardour that would be a Lua script. It can almost certainly be done as a script, but it doesn’t exist right now.

Hi Paul, thanks for posting, I understand now, no plugin,
and I have no clue as to how LUA Script works, maybe someone
smart will take this on, It would be extremely valuable in circumstances
where one wants to record a live show into a daw located on stage,
and trigger this from the mixer beside it also on stage,
using one of the many apps that now come with such mixers,
as a lot of these rack / stage based mixers do not come with recording
built in let alone multi track recording.

In any event , thanks for commenting

You can just use any of the OSC enabled controllers (TouchOSC) for example, from your phone, to control Ardour remotely. I didn’t quite realize that you just wanted a remote control.

Hi Paul, I actually got it working on reaper, using a web interface.
Also a kind gentleman on the reaper forum sent me a track template
that works by feeding / inputting audio to a track, that is turned down,
and set to monitor record.
I can source and route this audio from any source on the rack mixer
and route through the rack mixer into a DAW, via USB to a track
specifically set up to receive audio.
This track has two plug-ins on it, first off a Gate, that when it opens
by the audio being input through it, it sends a midi note to another plug-in
on the same track,
this other plug-in on receipt of that midi note starts the recording.
The Gate is a VST, the plug-in that triggers reaper to record is a VSTI.
This being so, may be they would work on Ardour and this is why
I mention them here.

Using a gate like that is totally different from what you described. There are no VST plugins that can change the record state of Reaper or Ardour. There may be Reaper builtin plugins that can do that, but those (Reaplugins) are the equivalent of our own Lua-based plugins. We just don’t happen to have a trigger one right now.

Your original message suggested to me that you want a way to start recording at a given time, when you are not in front of the computer. You were imagining using incoming audio as a “trigger” to start that.

However, you can also just do this with OSC (or MIDI) as a remote control. There’s no real need for a plugin or script of any kind, assuming you have either a phone or some sort of MIDI device that you can have near you when you are recording.

The rack mixer I talk about caters for FOH, it also has a USB port
than can connect it to a DAW as an audio interface, it can do both
these tasks at the same time, all the tracks available on the mixer
can be sent via usb to the DAW, there is one track on the DAW that
when it gets a signal, it will trigger the recording of all the other tracks fed
into the DAW via the USB from the mixer as it still performs FOH duty.
And now I can accomplish this, from either a laptop, hard or Wifi connected,
or any of the android or apple apps that are out ther to control the mixer.
This solves a lot of problems for people who want to record multi tracks
from the likes of a Berhinger X32 that can perform FOH and feed a DAW
at the same time, otherwise there is no other way to record multiple tracks
from such a rack mixer unless one gets a fany card for the Mixer, and another
Fancy one for the likes of a workstation, but with the system I mentioned here
recording multi tracks from the X32 can be done to a laptop using via the same
wired or wireless app that controlls the X32.

I sit in the audience, so no devices other than Surface Pro, or and android tablet.
The gate plug-in I mention is a standard plug-in that comes with reaper, ReaGate.
The Second plug-in I mention is called Rea_Learn, it is not included in reaper,
it comes from here,

And you are probably right Paul, I just call them plug-ins because
they are listed in reaper, one under VST, the other when installed
pops up as a VSTi

Android tablet is fine. Just install TouchOSC and you can control Ardour to your heart’s desire (and more).

Realearn is a plugin meant specifically for Reaper, and uses part of Reaper’s own extensibility/scripting capabilities. You could do exactly the same thing in Ardour too. It just hasn’t been done so far.

Thanks Paul, not enough Grey Matter here to begin learning
how to code.

Are you sure we don’t have a lua trigger ? Wouldn’t “voice_activate.lua” be what you want (provided you record-armed everything correctly) ? The description is « Roll the transport when the signal level on the plugin’s input exceeds a given threshold. »

Though of course, TouchOSC and similar are probably better suited for the task anyway (with their ability to arm/disarm tracks, start and stop the transport, etc.). Anything audio- and trigger- based would be coarse at best unless you devise a clever pitch scheme to transmit commands, but then you are reinventing the modem.