95 lines
3.2 KiB
Rust
95 lines
3.2 KiB
Rust
//! Records a WAV file (roughly 3 seconds long) using the default input device and format.
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//!
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//! The input data is recorded to "$CARGO_MANIFEST_DIR/recorded.wav".
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extern crate anyhow;
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extern crate cpal;
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extern crate hound;
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use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
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use std::fs::File;
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use std::io::BufWriter;
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use std::sync::{Arc, Mutex};
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fn main() -> Result<(), anyhow::Error> {
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// Use the default host for working with audio devices.
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let host = cpal::default_host();
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// Setup the default input device and stream with the default input format.
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let device = host
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.default_input_device()
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.expect("Failed to get default input device");
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println!("Default input device: {}", device.name()?);
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let format = device
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.default_input_format()
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.expect("Failed to get default input format");
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println!("Default input format: {:?}", format);
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// The WAV file we're recording to.
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const PATH: &'static str = concat!(env!("CARGO_MANIFEST_DIR"), "/recorded.wav");
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let spec = wav_spec_from_format(&format);
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let writer = hound::WavWriter::create(PATH, spec)?;
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let writer = Arc::new(Mutex::new(Some(writer)));
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// A flag to indicate that recording is in progress.
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println!("Begin recording...");
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// Run the input stream on a separate thread.
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let writer_2 = writer.clone();
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let err_fn = move |err| {
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eprintln!("an error occurred on stream: {}", err);
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};
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let data_fn = move |data: &cpal::Data| match data.sample_format() {
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cpal::SampleFormat::F32 => write_input_data::<f32, f32>(data, &writer_2),
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cpal::SampleFormat::I16 => write_input_data::<i16, i16>(data, &writer_2),
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cpal::SampleFormat::U16 => write_input_data::<u16, i16>(data, &writer_2),
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};
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let stream = device.build_input_stream(&format, data_fn, err_fn)?;
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stream.play()?;
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// Let recording go for roughly three seconds.
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std::thread::sleep(std::time::Duration::from_secs(3));
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drop(stream);
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writer.lock().unwrap().take().unwrap().finalize()?;
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println!("Recording {} complete!", PATH);
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Ok(())
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}
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fn sample_format(format: cpal::SampleFormat) -> hound::SampleFormat {
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match format {
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cpal::SampleFormat::U16 => hound::SampleFormat::Int,
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cpal::SampleFormat::I16 => hound::SampleFormat::Int,
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cpal::SampleFormat::F32 => hound::SampleFormat::Float,
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}
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}
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fn wav_spec_from_format(format: &cpal::Format) -> hound::WavSpec {
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hound::WavSpec {
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channels: format.channels as _,
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sample_rate: format.sample_rate.0 as _,
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bits_per_sample: (format.data_type.sample_size() * 8) as _,
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sample_format: sample_format(format.data_type),
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}
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}
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type WavWriterHandle = Arc<Mutex<Option<hound::WavWriter<BufWriter<File>>>>>;
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fn write_input_data<T, U>(input: &cpal::Data, writer: &WavWriterHandle)
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where
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T: cpal::Sample,
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U: cpal::Sample + hound::Sample,
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{
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let input = input.as_slice::<T>().expect("unexpected sample format");
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if let Ok(mut guard) = writer.try_lock() {
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if let Some(writer) = guard.as_mut() {
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for &sample in input.iter() {
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let sample: U = cpal::Sample::from(&sample);
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writer.write_sample(sample).ok();
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}
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}
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}
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}
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