AudioToMidi Plugin

[Smk]

Hello everyone,

I have an idea: I want to convert an audio signal into MIDI CC so that I can control MIDI instruments—like strings or piano—using my guitar. Here is where I stand so far:

Audio, MIDI, and MOD are all new to me. When I saw the MOD Desktop environment, I wanted to give it a try. I don’t yet know how to compile the code for the MOD device itself; right now, I’m still experimenting with pitch detection, guitar attack sensitivity, and determining exactly when to trigger “note-off” messages.

If anyone has ideas on how to improve this process, or advice on compiling and installing it for the MOD platform, I’d really appreciate the input.

Audio to Midi Plugin Mod Desktop / Mod Dwarf (Test)

[pilal]

You should use mod-plugin-builder to build plugins for mod devices. Once your docker image is built with a local folder linked, type “source local.env moddwarf-new” (or another available target), then build your plugin.

Mod plugin builder on Wiki

[Smk]

Thanks, I’ll give that a try sometime soon.
If anyone has any other ideas on how to debug a plugin, that would also help me fix my remaining bugs (related to detection and transmission). It runs on an external device—or as a plugin instance—so I unfortunately can’t use IDE debugging the way I’m used to with standard programs. Or am I mistaken about that?

[khz]

Take a look here, for example—you might find some resources, ideas, etc.:

New plugin GuitarMidi-LV2

Hi. I don’t know if this is the right place here on the mod forum: I’d like to announce the release of my LV2 plugin GuitarMidi (https://github.com/geraldmwangi/GuitarMidi-LV2). It analyses polyphonic audio from a guitar signal and extracts the individual notes. It’s in early stages and has some bugs I’ve documented in the readme. It isnt yet available for the mod, but I’ll work on that once it works well on the PC I’d be happy for feedback. I will also announce this on the linux audio mail…

Envelope follower

[jimsondrift]

Im the author of guitarmidi (GitHub - geraldmwangi/GuitarMidi-LV2: A concept for guitar to midi as an lv2 plugin · GitHub).

GuitarMidi-lv2 can do this, its currently available for linux. Im looking into getting it on the dwarf but it is a very hard task

[jimsondrift]

you can check out my youtube channel to see it in action https://www.youtube.com/@JDriftAudio

[jimsondrift]

I just looked at your repo. Years ago I also used aubio until i developed my own approach. If you want you can contribute to my guitarmidi-lv2. It its fully polyphonic and realtime down to the lowest string/note. Thats where aubio fails

[Smk]

The build system is broken for me. It attempts to use a kernel version that no longer exists on kernel.org. When I have more time, I will address this issue with MOD Audio via a GitHub issue; that way, it is properly documented and helps others set up a build system.

[gianfranco]

Are you building for moddwarf-new? Please try “./bootstrap.sh moddwarf-new”

[Smk]

@gianfranco

/bootstrap.sh moddwarf-new”

[INFO ] Retrieving needed toolchain components’ tarballs
[EXTRA] Retrieving ‘make-4.3’
[EXTRA] Verifying SHA512 checksum for ‘make-4.3.tar.gz’
[EXTRA] Retrieving ‘linux-4.4.302’
[ERROR] linux: download failed
[ERROR]

I also haven’t yet understood the difference between moddwarf and moddwarf-new.

[pilal]

moddwarf-new builds a less older toolchain.

The V4 kernel branch has been removed from the kernel.org server.

If you are not using docker and are using ./bootstrap.sh, you can try this fix: edit bootstrap.sh. Go to line 136.

Replace bloc:

if [ ! -f .stamp_built2 ]; then
sed -i -e 's/.PHONY: $(PHONY)/.PHONY: build $(PHONY)/' ct-ng
./ct-ng build
touch .stamp_built2
fi

with:

if [ ! -f .stamp_built2 ]; then
sed -i -e 's/.PHONY: $(PHONY)/.PHONY: build $(PHONY)/' ct-ng
_LINUX_VERSION=$(grep "^CT_LINUX_VERSION=" "${SOURCE_DIR}/toolchain/${TOOLCHAIN_PLATFORM}.config" | cut -d'"' -f2)
_LINUX_MAJOR=$(echo ${_LINUX_VERSION} | cut -d'.' -f1)
if [ "${_LINUX_MAJOR}" -lt 5 ] && [ ! -f "${DOWNLOAD_DIR}/linux-${_LINUX_VERSION}.tar.gz" ]; then
wget "``https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/snapshot/linux-${_LINUX_VERSION}.tar.gz``"
-O "${DOWNLOAD_DIR}/linux-${_LINUX_VERSION}.tar.gz"
fi
./ct-ng build
touch .stamp_built2
fi

[Smk]

The kernel part works that way, but other problems keep cropping up, and I have no idea what else might come up next. Right now, I’m stuck on Python; Python 3.12 is too new—I think I need to install an older Linux version in a VM, or how do you guys build your plugins?

[pilal]

Are running the bootstrap.sh directly or are you trying t build the docker image? I would recommend the use of docker, but the docker file in the mod-audio repo will also face the kernel 4.x issue.

I did bootstraping directly on a debian 12 once quite some time ago, i don’t really remember what came up, but i built the docker image for modDuoX 17 days ago (to be very precise!) on macOS and I didn’t encountered the kernel 4.x issue back then and beside a few typos in the command line given in the wiki everything went fine.

[Smk]

I’ve rewritten the Dockerfile so that it no longer performs a git clone and instead uses my local changes. I’ve included your Bootstrap fix, and the build is currently still running. I’ll let you know once it’s finished.

Docker Result
EDIT:
2051.6 WARNING: no hash file for kxstudio-lv2-extensions-8b5f6cb9cd75e300958c9aacac253d44c964e80b.tar.gz
2051.6 svn: E170013: Unable to connect to a repository at URL ‘svn - Revision 4625: /libgig/trunk’
2051.6 svn: E000110: Error running context: Connection timed out
2051.6 --2026-07-04 16:49:44-- http://sources.buildroot.net/libgig-2855.tar.gz
2051.6 Resolving sources.buildroot.net (sources.buildroot.net)… 172.67.72.56, 104.26.0.37, 104.26.1.37, …
2051.6 Connecting to sources.buildroot.net (sources.buildroot.net)|172.67.72.56|:80… connected.
2051.6 HTTP request sent, awaiting response… 404 Not Found
2051.6 2026-07-04 16:49:44 ERROR 404: Not Found.
2051.6
2051.6 make: *** [package/pkg-generic.mk:115: /root/mod-workdir/moddwarf-new/build/libgig-2855/.stamp_downloaded] Error 1
EDIT END

[jon]

@pilal

beside a few typos in the command line given in the wiki everything went fine

Hey @pilal, if you could eventually DM me and pinpoint the pages and the typos it would be great! So I can quickly fix that

[Smk]

@jon Do you happen to have the SVN Trunk local? I can’t get SVN because of timeout. Does this repo still exist? Could you create a copy of GitHub if you have files locally?

Greeting

Update:
I took a closer look at the build. Regarding libgig (the SVN and download servers are either gone or broken): it is a hard system dependency, yet I couldn’t find any plugin that actually uses it. That is why I disabled it in my fork, which allowed me to set up the appropriate environment.

Since I wanted to use Docker, I made a few minor adjustments to the Dockerfile to simplify things. Now, the GitHub URL and so on can be controlled via an ENV file.

What works for me?

git clone https://github.com/knasan/mod-plugin-builder.git
cd mod-plugin-builder/docker
# create .env
# MPB_GIT_URL=https://github.com/knasan/mod-plugin-builder
# MPB_PLATFORM=moddwarf-new
# MPB_TARGET=full

docker buildx with my patches

source .env
docker buildx build
--build-arg MPB_GIT_URL="$MPB_GIT_URL"
--build-arg platform="$MPB_PLATFORM"
--build-arg target="$MPB_TARGET"
-t mpb-dev .

It’s being built locally on my machine now.
I have a few gigs coming up over the next two weeks, so I haven’t dared to test this on my own hardware yet. I’ll get around to that once the gigs are over.

Now I can check whether the plugins can theoretically be compiled.

[jon]

Great that you found a solution @Smk!

As far as I’m aware, the documentation for the development stuff on the wiki is here and there outdated. I should fix it, but as I’m not into the MOD software and plugins development (and I guess that my developer skills are too low for most of the MOD stuff), any help from you guys in order to fix the documentation would be awesome! In summary, 2 things would be great for me:

1. point out what is written there and doesn’t work

2. if you happen to find a solution, let me know what it was so I can update it on the wiki materials

[Smk]

@jon

1. point out what is written there and doesn’t work

2. if you happen to find a solution, let me know what it was so I can update it on the wiki materials

Do you have access to GitHub?
I think the first step should be to modernize the Dockerfile.

Just like I did in my fork.

Why?
That way, anyone can set up their build environment independently and test their changes much more easily without breaking GitHub - mod-audio/mod-plugin-builder: MOD Plugin Builder · GitHub .

The problem is that, as the Dockerfile is currently written, GitHub - mod-audio/mod-plugin-builder: MOD Plugin Builder · GitHub is a hard dependency.

[Smk]

Okay, I couldn’t resist running a test after all.
I was feeling pretty bold today

First, I installed the alabs-mod-custom-images custom image, then compiled my plugin and transferred it to the Dwarf. After a lot of debugging, I finally got it working.

@jon @pilal

So I can say that the hard linking of libgig was the right decision. This way, the plugins can definitely be compiled and work properly.

And I can say with a clear conscience that this would be a solution, in case anyone else runs into these problems.

Thank you for your support.

[jon]

@Smk

So I can say that the hard linking of libgig was the right decision. This way, the plugins can definitely be compiled and work properly.

Just to see if I understood. Do you mean that, as it is currently in GitHub - mod-audio/mod-plugin-builder: MOD Plugin Builder · GitHub , everything is correct and works as supposed?