Crate ghakuf

A Rust library for parsing/building SMF (Standard MIDI File).

Examples

ghakuf has parse module and build module separatory.

Perser

ghakuf's parser is made by Event-driven online algorithm. You must prepare original handler implementing Handler trait to catch SMF messages. Any number of handlers you can add for parser if you want.

use ghakuf::messages::*;
use ghakuf::reader::*;
use std::path;

let path = path::Path::new("tests/test.mid");
let mut handler = HogeHandler {};
let mut reader = Reader::new(&mut handler, &path).unwrap();
let _ = reader.read();

struct HogeHandler {}
impl Handler for HogeHandler {
    fn header(&mut self, format: u16, track: u16, time_base: u16) {
      let _ = (format, track, time_base);
    }
    fn meta_event(&mut self, delta_time: u32, event: &MetaEvent, data: &Vec<u8>) {
      let _ = (delta_time, event, data);
    }
    fn midi_event(&mut self, delta_time: u32, event: &MidiEvent) {
      let _ = (delta_time, event);
    }
    fn sys_ex_event(&mut self, delta_time: u32, event: &SysExEvent, data: &Vec<u8>) {
      let _ = (delta_time, event, data);
    }
    fn track_change(&mut self) {}
}

Builder

ghakuf build SMF by Message enums. Message enum consists of MetaEvent, MidiEvent, SysExEvent, and TrackChange. You can use running status if you want. At track change, you should use not only MetaEvent::EndOfTrack message, but also TrackChange message.

use ghakuf::messages::*;
use ghakuf::writer::*;
use std::path;

let path = path::Path::new("tests/lib_doctest.mid");
let tempo: u32 = 60 * 1000000 / 102; //bpm:102
let messages: Vec<Message> = vec![
    Message::MetaEvent {
        delta_time: 0,
        event: MetaEvent::SetTempo,
        data: [(tempo >> 16) as u8, (tempo >> 8) as u8, tempo as u8].to_vec(),
    },
    Message::MetaEvent {
        delta_time: 0,
        event: MetaEvent::EndOfTrack,
        data: Vec::new(),
    },
    Message::TrackChange,
    Message::MidiEvent {
        delta_time: 0,
        event: MidiEvent::NoteOn { ch: 0, note: 0x3c, velocity: 0x7f },
    },
    Message::MidiEvent {
        delta_time: 192,
        event: MidiEvent::NoteOn { ch: 0, note: 0x40, velocity: 0 },
    },
    Message::MetaEvent {
        delta_time: 0,
        event: MetaEvent::EndOfTrack,
        data: Vec::new(),
    }
];

let mut writer = Writer::new();
writer.running_status(true);
for message in &messages {
    writer.push(message);
}
writer.write(&path);

Modules

formats	SMF Formats and Variable Length Quantity
messages	enums representing SMF messages (Meta event, MIDI event, System exclusive event)
reader	SMF parser and handler
writer	SMF builder