tone.rs - mozsearch

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// Copyright © 2011 Mozilla Foundation

//

// This program is made available under an ISC-style license.  See the

// accompanying file LICENSE for details.

//! libcubeb api/function test. Plays a simple tone.

extern crate cubeb;

mod common;

use cubeb::{MonoFrame, Sample};

use std::f32::consts::PI;

use std::thread;

use std::time::Duration;

const SAMPLE_FREQUENCY: u32 = 48_000;

const STREAM_FORMAT: cubeb::SampleFormat = cubeb::SampleFormat::S16LE;

type Frame = MonoFrame<i16>;

fn main() {

    let ctx = common::init("Cubeb tone example").expect("Failed to create cubeb context");

    let params = cubeb::StreamParamsBuilder::new()

        .format(STREAM_FORMAT)

        .rate(SAMPLE_FREQUENCY)

        .channels(1)

        .layout(cubeb::ChannelLayout::MONO)

        .take();

    let mut position = 0u32;

    let mut builder = cubeb::StreamBuilder::<Frame>::new();

    builder

        .name("Cubeb tone (mono)")

        .default_output(&params)

        .latency(0x1000)

        .data_callback(move |_, output| {

            // generate our test tone on the fly

            for f in output.iter_mut() {

                // North American dial tone

                let t1 = (2.0 * PI * 350.0 * position as f32 / SAMPLE_FREQUENCY as f32).sin();

                let t2 = (2.0 * PI * 440.0 * position as f32 / SAMPLE_FREQUENCY as f32).sin();

                f.m = i16::from_float(0.5 * (t1 + t2));

                position += 1;

            output.len() as isize

})

        .state_callback(|state| {

            println!("stream {:?}", state);

});

    let stream = builder.init(&ctx).expect("Failed to create cubeb stream");

    stream.start().unwrap();

    thread::sleep(Duration::from_millis(500));

    stream.stop().unwrap();