spectrogram 0.1.0

Documentation 
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extern crate hound;
extern crate image;
extern crate goertzel;

pub fn draw<P: AsRef<std::path::Path>>(wav: P, image: P) {
    let mut reader = hound::WavReader::open(wav).unwrap();
    let sample_rate = reader.spec().sample_rate as f32;
    let samples: Vec<i16> = reader.samples().map(|x|x.unwrap()).collect();
    let mut image_data: Vec<u8> = vec![];
    let mut image_lines = 0;
    for chunk in samples.chunks(256) {
        for bin in (0 .. 30).map(|x| (x * 256) as f32) {
            let p = goertzel::Parameters::new(bin, sample_rate, 256);
            let v = p.start().add(chunk).finish_mag();
            image_data.push((v/1000.) as u8);
            print!("{:14.0} ", v);
        }
        println!("");
        image_lines+=1;
    }
    println!("{}x{} image", 30, image_lines);
    image::save_buffer(image, &image_data[..], 30, image_lines, image::ColorType::Gray(8));
}

#[test]
fn it_works() {
    draw("TTY.wav", "image.png")
}