Create sound on sound with the hound

Question

How can you make one file, for example: " out.wav ", and in it add " 1.wav " 10 times, but without delays. That is, to superimpose the sound on another sound even if the previous one has not finished playing. As I've been trying to do for about an hour and a half now, and all I get is playback one by one (ie: first the sound plays completely)

Simplest code:

use hound::{WavReader, WavWriter};

fn main() {
    let mut reader = WavReader::open("1.wav").unwrap();
    let spec = reader.spec();
    let mut writer = WavWriter::create("output.wav", spec).unwrap();

    for _ in 0..10 {
        for sample in reader.samples::<i16>() {
            writer.write_sample(sample.unwrap()).unwrap();
        }

        reader.seek(0).unwrap();
    }
}

Answer 1

You have to somehow read & mix the multiple sounds you want to play at the same time.

Here is an example that plays 10 times the same sound each delayed by half that sounds length, mixed by simply averaging both clips playing at the same time.

use hound::{WavReader, WavWriter};

fn main() {
    let mut reader = WavReader::open("1.wav").unwrap();
    let mut reader2 = WavReader::open("1.wav").unwrap();
    let mut writer = WavWriter::create("output.wav", spec).unwrap();
    let l = reader.len();
    reader.seek(l/2).unwrap();
    for i in 0..l*10 {
        if i % (l/2) == 0 {
            reader.seek(0).unwrap();
            let tmp = reader;
            reader = reader2;
            reader2 = tmp;
        }
        let s1 = reader.samples::<i16>().next().unwrap().unwrap();
        let s2 = reader2.samples::<i16>().next().unwrap().unwrap();
        let sample = s1/2 + s2/2;
        writer.write_sample(sample).unwrap();
    }
}

Which can definitely be cleaned up a lot (ie store the samples in a Vec once and just read from there)