lemur/src/audio.rs

267 lines
8.9 KiB
Rust

use std::time::Duration;
use anyhow::{Context, Result, bail};
use audioadapter_buffers::direct::InterleavedSlice;
use cpal::{
Device, FromSample, Sample, SampleFormat, SizedSample, StreamConfig,
traits::{DeviceTrait, HostTrait, StreamTrait},
};
use itertools::Itertools;
use rubato::{Adjustable as _, Resampler};
use tracing::warn;
struct CpalAudio {
#[allow(unused)]
stream: cpal::Stream,
sampler: rubato::Async<f32>,
input_buffer: Vec<f32>,
output_buffer: Vec<f32>,
sample_sink: rtrb::Producer<f32>,
}
const VB_FREQUENCY: usize = 41700;
impl CpalAudio {
fn init() -> Result<Self> {
let host = cpal::default_host();
let device = host
.default_output_device()
.context("no output device available")?;
let default_rate = device.default_output_config()?.sample_rate();
let supported_config = device
.supported_output_configs()?
.filter(|c| {
c.contains_rate(default_rate)
&& matches!(
c.sample_format(),
SampleFormat::F32
| SampleFormat::F64
| SampleFormat::I32
| SampleFormat::I16
)
})
.max_by(|a, b| a.cmp_default_heuristics(b))
.context("no suitable output config available")?
.with_sample_rate(default_rate);
let mut config = supported_config.config();
let resample_ratio = config.sample_rate as f64 / VB_FREQUENCY as f64;
let chunk_size = (834.0 * resample_ratio) as usize;
let sampler = rubato::Async::new_poly(
resample_ratio,
64.0,
rubato::PolynomialDegree::Cubic,
chunk_size,
2,
rubato::FixedAsync::Output,
)?;
config.buffer_size = cpal::BufferSize::Fixed(sampler.output_frames_max() as u32);
match supported_config.sample_format() {
SampleFormat::F32 if config.channels == 2 => {
Self::new_f32_stereo(device, config, sampler)
}
SampleFormat::F32 => Self::new::<f32>(device, config, sampler),
SampleFormat::F64 => Self::new::<f64>(device, config, sampler),
SampleFormat::I32 => Self::new::<i32>(device, config, sampler),
SampleFormat::I16 => Self::new::<i16>(device, config, sampler),
_ => bail!("unsupported sample format"),
}
}
fn new_f32_stereo(
device: Device,
config: StreamConfig,
sampler: rubato::Async<f32>,
) -> Result<Self> {
let input_buffer = Vec::with_capacity(sampler.nbr_channels() * sampler.input_frames_max());
let output_buffer = vec![0.0; sampler.nbr_channels() * sampler.output_frames_max()];
let (sample_sink, mut sample_source) =
rtrb::RingBuffer::new(sampler.output_frames_max() * 4);
let stream = device.build_output_stream(
config,
move |data: &mut [f32], _| {
let requested = data.len();
let chunk = match sample_source.read_chunk(data.len()) {
Ok(c) => c,
Err(rtrb::chunks::ChunkError::TooFewSlots(n)) => {
sample_source.read_chunk(n).unwrap()
}
};
let len = chunk.len();
let (first, second) = chunk.as_slices();
data[0..first.len()].copy_from_slice(first);
data[first.len()..len].copy_from_slice(second);
for rest in &mut data[len..requested] {
*rest = 0.0;
}
chunk.commit_all();
},
move |error| warn!(%error, "stream error"),
None,
)?;
stream.play()?;
Ok(Self {
stream,
sampler,
input_buffer,
output_buffer,
sample_sink,
})
}
fn new<S: SizedSample + FromSample<f32>>(
device: Device,
config: StreamConfig,
sampler: rubato::Async<f32>,
) -> Result<Self> {
let input_buffer = Vec::with_capacity(sampler.nbr_channels() * sampler.input_frames_max());
let output_buffer = vec![0.0; sampler.nbr_channels() * sampler.output_frames_max()];
let (sample_sink, mut sample_source) =
rtrb::RingBuffer::new(sampler.output_frames_max() * 4);
let channels = config.channels as usize;
let stream = device.build_output_stream(
config,
move |data: &mut [S], _| {
let requested = data.len() * 2 / channels;
let chunk = match sample_source.read_chunk(requested) {
Ok(c) => c,
Err(rtrb::chunks::ChunkError::TooFewSlots(n)) => {
sample_source.read_chunk(n).unwrap()
}
};
let (first, second) = chunk.as_slices();
let new_samples = first
.iter()
.chain(second)
.map(|s: &f32| (*s).to_sample())
.chunks(2);
let buffer = data.iter_mut().chunks(channels);
for (dst, samples) in buffer.into_iter().zip(&new_samples) {
// channels beyond the first two are zeroed
let src = samples.chain(std::iter::repeat(S::EQUILIBRIUM));
for (d, s) in dst.zip(src) {
*d = s;
}
}
chunk.commit_all();
},
move |error| warn!(%error, "stream error"),
None,
)?;
stream.play()?;
Ok(Self {
stream,
sampler,
input_buffer,
output_buffer,
sample_sink,
})
}
fn update(&mut self, mut samples: &[f32]) {
while self.input_buffer.len() + samples.len() >= self.sampler.input_frames_next() * 2 {
let samples_needed =
(self.sampler.input_frames_next() * 2).saturating_sub(self.input_buffer.len());
let (current_samples, future_samples) = samples.split_at(samples_needed);
self.input_buffer.extend_from_slice(current_samples);
samples = future_samples;
let buffer_in =
InterleavedSlice::new(&self.input_buffer, 2, self.sampler.input_frames_next())
.unwrap();
let mut buffer_out = InterleavedSlice::new_mut(
&mut self.output_buffer,
2,
self.sampler.output_frames_next(),
)
.unwrap();
let (_, output_samples) = self
.sampler
.process_into_buffer(&buffer_in, &mut buffer_out, None)
.unwrap();
let chunk = match self.sample_sink.write_chunk_uninit(output_samples * 2) {
Ok(c) => c,
Err(rtrb::chunks::ChunkError::TooFewSlots(n)) => {
self.sample_sink.write_chunk_uninit(n).unwrap()
}
};
chunk.fill_from_iter(self.output_buffer[..output_samples * 2].iter().copied());
self.input_buffer.clear();
}
self.input_buffer.extend_from_slice(samples);
while self.sample_sink.slots() < self.sampler.output_frames_max() * 2 {
std::thread::sleep(Duration::from_micros(500));
}
}
fn set_speed(&mut self, speed: f64) -> Result<()> {
self.sampler
.set_resample_ratio_relative(1.0 / speed, false)?;
Ok(())
}
}
struct NoAudio {
speed: f64,
}
impl NoAudio {
fn new() -> Self {
Self { speed: 1.0 }
}
fn update(&mut self, samples: &[f32]) {
let samples = (samples.len() / 2) as f64;
let elapsed = Duration::from_secs_f64(samples / (VB_FREQUENCY as f64 * self.speed));
std::thread::sleep(elapsed);
}
fn set_speed(&mut self, speed: f64) -> Result<()> {
self.speed = speed;
Ok(())
}
}
#[allow(clippy::large_enum_variant)]
enum AudioInner {
Cpal(CpalAudio),
None(NoAudio),
}
pub struct Audio(AudioInner);
impl Audio {
pub fn init() -> Self {
match CpalAudio::init() {
Ok(a) => Self(AudioInner::Cpal(a)),
Err(e) => {
warn!("could not play audio: {e}");
Self(AudioInner::None(NoAudio::new()))
}
}
}
pub fn update(&mut self, samples: &[f32]) {
match &mut self.0 {
AudioInner::Cpal(a) => a.update(samples),
AudioInner::None(a) => a.update(samples),
}
}
pub fn set_speed(&mut self, speed: f64) -> Result<()> {
match &mut self.0 {
AudioInner::Cpal(a) => a.set_speed(speed),
AudioInner::None(a) => a.set_speed(speed),
}
}
}