# bbx_midi
MIDI message parsing and streaming utilities for audio applications.
## Features
- **MIDI message parsing**: Parse raw MIDI bytes into structured messages
- **Message type helpers**: Extract note, velocity, pitch wheel, control data
- **Real-time buffer**: Pre-allocated buffer for use in audio callbacks
- **Input streaming**: Real-time MIDI input via `midir`
- **FFI compatible**: `#[repr(C)]` types for C interop
## Message Types
- `NoteOn` / `NoteOff` - Note events with velocity
- `ControlChange` - CC messages (mod wheel, sustain, etc.)
- `PitchWheel` - Pitch bend with 14-bit resolution
- `ProgramChange` - Instrument/patch changes
- `PolyphonicAftertouch` - Per-note pressure
- `ChannelAftertouch` - Channel-wide pressure
## MidiEvent
For sample-accurate MIDI timing in audio callbacks:
```rust
use bbx_midi::{MidiMessage, MidiEvent};
let event = MidiEvent {
message: MidiMessage::new([0x90, 60, 100]),
sample_offset: 128, // Process at sample 128 in buffer
};
```
Used with `PluginDsp::process()` for synthesizer plugins.
## Usage
```rust
use bbx_midi::{MidiMessage, MidiMessageStatus, MidiMessageBuffer};
// Parse raw MIDI bytes
let msg = MidiMessage::new([0x90, 60, 100]); // Note On, C4, velocity 100
if msg.get_status() == MidiMessageStatus::NoteOn {
println!("Note: {}", msg.get_note().unwrap()); // "C4"
println!("Frequency: {} Hz", msg.get_note_frequency().unwrap()); // ~261.6
println!("Velocity: {}", msg.get_velocity().unwrap()); // 100
}
// Pre-allocated buffer for real-time use
let mut buffer = MidiMessageBuffer::new(256);
buffer.push(msg);
for message in buffer.iter() {
// Process messages...
}
buffer.clear(); // Reset without deallocation
```
## Cargo Features
### `streaming`
Enables real-time MIDI input via `midir`:
```toml
[dependencies]
bbx_midi = { version = "...", features = ["streaming"] }
```
```rust
use bbx_midi::{stream::MidiInputStream, MidiMessage, MidiMessageStatus};
// Create stream with optional filters
let stream = MidiInputStream::new(
vec![MidiMessageStatus::NoteOn, MidiMessageStatus::NoteOff],
|msg| println!("Received: {:?}", msg),
);
// Start listening (prompts for port selection)
let handle = stream.init();
```
Used by `bbx_sandbox` for terminal-based DSP testing with live MIDI input.
## License
MIT