From 56234e4e0749cb059e882180f1ab79e5f1498cfa Mon Sep 17 00:00:00 2001
From: Nicole Tietz-Sokolskaya <me@ntietz.com>
Date: Mon, 2 Sep 2024 10:59:31 -0400
Subject: [PATCH] Reads MIDI events and prints them to the terminal
---
Cargo.toml | 2 ++
src/main.rs | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 59 insertions(+), 1 deletion(-)
diff --git a/Cargo.toml b/Cargo.toml
index 17f1b4b..1291649 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,4 +4,6 @@ version = "0.1.0"
edition = "2021"
[dependencies]
+anyhow = "1.0.86"
midir = "0.10.0"
+thiserror = "1.0.63"
diff --git a/src/main.rs b/src/main.rs
index e7a11a9..a6f105b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,59 @@
+use std::io::stdin;
+use std::io::Read;
+
+use anyhow::{anyhow, Result};
+use midir::{MidiInput, MidiInputPort};
+
fn main() {
- println!("Hello, world!");
+ match run() {
+ Ok(_) => {}
+ Err(err) => {
+ println!("Ended with error: {}", err);
+ }
+ }
}
+
+fn run() -> Result<()> {
+ let midi_in = MidiInput::new("keyboard")?;
+
+ let midi_device = find_first_midi_device(&midi_in)?;
+ let port_name = midi_in.port_name(&midi_device)?;
+
+ let _midi_connection = match midi_in.connect(&midi_device, &port_name, handle_midi_event, ()) {
+ Ok(m) => m,
+ Err(err) => return Err(anyhow!("failed to connect to device: {}", err)),
+ };
+
+ // TODO: instead, listen for a signal like control-d
+ let mut buf = String::new();
+ stdin().read_line(&mut buf)?;
+
+ Ok(())
+}
+
+fn handle_midi_event(timestamp: u64, message: &[u8], _extra_data: &mut ()) {
+ println!("{timestamp} > {message:?}")
+}
+
+/// Finds the first MIDI input port which corresponds to a physical MIDI device
+/// connected to this computer.
+fn find_first_midi_device(midi_in: &MidiInput) -> Result<MidiInputPort> {
+ let ports = midi_in.ports();
+
+ let mut physical_ports = ports.iter().filter(|p| {
+ midi_in
+ .port_name(p)
+ .map_or(false, |n| !n.starts_with("Midi Through:"))
+ });
+
+ physical_ports
+ .next()
+ .cloned()
+ .ok_or(anyhow!("no physical MIDI devices found"))
+}
+
+// "Midi Through" is automatically created bya the snd-seq-dummy kernel module.
+// We can ignore it, since it's not a physical MIDI device, which is what we
+// are looking for.
+//
+// Source: https://www.reddit.com/r/linuxaudio/comments/jsrl31/comment/gc16qwu/