51 lines
1.6 KiB
Rust
51 lines
1.6 KiB
Rust
extern crate anyhow;
|
|
extern crate cpal;
|
|
|
|
use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
|
|
|
|
fn main() -> Result<(), anyhow::Error> {
|
|
let host = cpal::default_host();
|
|
let device = host
|
|
.default_output_device()
|
|
.expect("failed to find a default output device");
|
|
let format = device.default_output_format()?;
|
|
let sample_rate = format.sample_rate.0 as f32;
|
|
let channels = format.channels as usize;
|
|
|
|
// Produce a sinusoid of maximum amplitude.
|
|
let mut sample_clock = 0f32;
|
|
let mut next_value = move || {
|
|
sample_clock = (sample_clock + 1.0) % sample_rate;
|
|
(sample_clock * 440.0 * 2.0 * 3.141592 / sample_rate).sin()
|
|
};
|
|
|
|
let err_fn = |err| eprintln!("an error occurred on stream: {}", err);
|
|
|
|
let data_fn = move |data: &mut cpal::Data| match data.sample_format() {
|
|
cpal::SampleFormat::F32 => write_data::<f32>(data, channels, &mut next_value),
|
|
cpal::SampleFormat::I16 => write_data::<i16>(data, channels, &mut next_value),
|
|
cpal::SampleFormat::U16 => write_data::<u16>(data, channels, &mut next_value),
|
|
};
|
|
|
|
let stream = device.build_output_stream(&format, data_fn, err_fn)?;
|
|
|
|
stream.play()?;
|
|
|
|
std::thread::sleep(std::time::Duration::from_millis(1000));
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn write_data<T>(output: &mut cpal::Data, channels: usize, next_sample: &mut dyn FnMut() -> f32)
|
|
where
|
|
T: cpal::Sample,
|
|
{
|
|
let output = output.as_slice_mut::<T>().expect("unexpected sample type");
|
|
for frame in output.chunks_mut(channels) {
|
|
let value: T = cpal::Sample::from::<f32>(&next_sample());
|
|
for sample in frame.iter_mut() {
|
|
*sample = value;
|
|
}
|
|
}
|
|
}
|