| Lift freeq's AV media plane out of sleek 90f8b89 nandi 19d ago | 1 | /* This example expose parameter to pass generator of sample. |
| 2 | Good starting point for integration of cpal into your application. |
| 3 | */ |
| 4 | |
| 5 | extern crate anyhow; |
| 6 | extern crate clap; |
| 7 | extern crate cpal; |
| 8 | |
| 9 | use cpal::{ |
| 10 | traits::{DeviceTrait, HostTrait, StreamTrait}, |
| 11 | SizedSample, I24, U24, |
| 12 | }; |
| 13 | use cpal::{FromSample, Sample}; |
| 14 | |
| 15 | fn main() -> anyhow::Result<()> { |
| 16 | let stream = stream_setup_for()?; |
| 17 | stream.play()?; |
| 18 | std::thread::sleep(std::time::Duration::from_millis(4000)); |
| 19 | Ok(()) |
| 20 | } |
| 21 | |
| 22 | pub enum Waveform { |
| 23 | Sine, |
| 24 | Square, |
| 25 | Saw, |
| 26 | Triangle, |
| 27 | } |
| 28 | |
| 29 | pub struct Oscillator { |
| 30 | pub sample_rate: f32, |
| 31 | pub waveform: Waveform, |
| 32 | pub current_sample_index: f32, |
| 33 | pub frequency_hz: f32, |
| 34 | } |
| 35 | |
| 36 | impl Oscillator { |
| 37 | fn advance_sample(&mut self) { |
| 38 | self.current_sample_index = (self.current_sample_index + 1.0) % self.sample_rate; |
| 39 | } |
| 40 | |
| 41 | fn set_waveform(&mut self, waveform: Waveform) { |
| 42 | self.waveform = waveform; |
| 43 | } |
| 44 | |
| 45 | fn calculate_sine_output_from_freq(&self, freq: f32) -> f32 { |
| 46 | let two_pi = 2.0 * std::f32::consts::PI; |
| 47 | (self.current_sample_index * freq * two_pi / self.sample_rate).sin() |
| 48 | } |
| 49 | |
| 50 | fn is_multiple_of_freq_above_nyquist(&self, multiple: f32) -> bool { |
| 51 | self.frequency_hz * multiple > self.sample_rate / 2.0 |
| 52 | } |
| 53 | |
| 54 | fn sine_wave(&mut self) -> f32 { |
| 55 | self.advance_sample(); |
| 56 | self.calculate_sine_output_from_freq(self.frequency_hz) |
| 57 | } |
| 58 | |
| 59 | fn generative_waveform(&mut self, harmonic_index_increment: i32, gain_exponent: f32) -> f32 { |
| 60 | self.advance_sample(); |
| 61 | let mut output = 0.0; |
| 62 | let mut i = 1; |
| 63 | while !self.is_multiple_of_freq_above_nyquist(i as f32) { |
| 64 | let gain = 1.0 / (i as f32).powf(gain_exponent); |
| 65 | output += gain * self.calculate_sine_output_from_freq(self.frequency_hz * i as f32); |
| 66 | i += harmonic_index_increment; |
| 67 | } |
| 68 | output |
| 69 | } |
| 70 | |
| 71 | fn square_wave(&mut self) -> f32 { |
| 72 | self.generative_waveform(2, 1.0) |
| 73 | } |
| 74 | |
| 75 | fn saw_wave(&mut self) -> f32 { |
| 76 | self.generative_waveform(1, 1.0) |
| 77 | } |
| 78 | |
| 79 | fn triangle_wave(&mut self) -> f32 { |
| 80 | self.generative_waveform(2, 2.0) |
| 81 | } |
| 82 | |
| 83 | fn tick(&mut self) -> f32 { |
| 84 | match self.waveform { |
| 85 | Waveform::Sine => self.sine_wave(), |
| 86 | Waveform::Square => self.square_wave(), |
| 87 | Waveform::Saw => self.saw_wave(), |
| 88 | Waveform::Triangle => self.triangle_wave(), |
| 89 | } |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | pub fn stream_setup_for() -> Result<cpal::Stream, anyhow::Error> |
| 94 | where |
| 95 | { |
| 96 | let (_host, device, config) = host_device_setup()?; |
| 97 | |
| 98 | match config.sample_format() { |
| 99 | cpal::SampleFormat::I8 => make_stream::<i8>(&device, config.into()), |
| 100 | cpal::SampleFormat::I16 => make_stream::<i16>(&device, config.into()), |
| 101 | cpal::SampleFormat::I24 => make_stream::<I24>(&device, config.into()), |
| 102 | cpal::SampleFormat::I32 => make_stream::<i32>(&device, config.into()), |
| 103 | cpal::SampleFormat::I64 => make_stream::<i64>(&device, config.into()), |
| 104 | cpal::SampleFormat::U8 => make_stream::<u8>(&device, config.into()), |
| 105 | cpal::SampleFormat::U16 => make_stream::<u16>(&device, config.into()), |
| 106 | cpal::SampleFormat::U24 => make_stream::<U24>(&device, config.into()), |
| 107 | cpal::SampleFormat::U32 => make_stream::<u32>(&device, config.into()), |
| 108 | cpal::SampleFormat::U64 => make_stream::<u64>(&device, config.into()), |
| 109 | cpal::SampleFormat::F32 => make_stream::<f32>(&device, config.into()), |
| 110 | cpal::SampleFormat::F64 => make_stream::<f64>(&device, config.into()), |
| 111 | sample_format => Err(anyhow::Error::msg(format!( |
| 112 | "Unsupported sample format '{sample_format}'" |
| 113 | ))), |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | pub fn host_device_setup( |
| 118 | ) -> Result<(cpal::Host, cpal::Device, cpal::SupportedStreamConfig), anyhow::Error> { |
| 119 | let host = cpal::default_host(); |
| 120 | |
| 121 | let device = host |
| 122 | .default_output_device() |
| 123 | .ok_or_else(|| anyhow::Error::msg("Default output device is not available"))?; |
| 124 | println!("Output device: {}", device.id()?); |
| 125 | |
| 126 | let config = device.default_output_config()?; |
| 127 | println!("Default output config: {config:?}"); |
| 128 | |
| 129 | Ok((host, device, config)) |
| 130 | } |
| 131 | |
| 132 | pub fn make_stream<T>( |
| 133 | device: &cpal::Device, |
| 134 | config: cpal::StreamConfig, |
| 135 | ) -> Result<cpal::Stream, anyhow::Error> |
| 136 | where |
| 137 | T: SizedSample + FromSample<f32>, |
| 138 | { |
| 139 | let num_channels = config.channels as usize; |
| 140 | let mut oscillator = Oscillator { |
| 141 | waveform: Waveform::Sine, |
| 142 | sample_rate: config.sample_rate as f32, |
| 143 | current_sample_index: 0.0, |
| 144 | frequency_hz: 440.0, |
| 145 | }; |
| 146 | let err_fn = |err| eprintln!("Error building output sound stream: {err}"); |
| 147 | |
| 148 | let time_at_start = std::time::Instant::now(); |
| 149 | println!("Time at start: {time_at_start:?}"); |
| 150 | |
| 151 | let stream = device.build_output_stream( |
| 152 | config, |
| 153 | move |output: &mut [T], _: &cpal::OutputCallbackInfo| { |
| 154 | // for 0-1s play sine, 1-2s play square, 2-3s play saw, 3-4s play triangle_wave |
| 155 | let time_since_start = std::time::Instant::now() |
| 156 | .duration_since(time_at_start) |
| 157 | .as_secs_f32(); |
| 158 | if time_since_start < 1.0 { |
| 159 | oscillator.set_waveform(Waveform::Sine); |
| 160 | } else if time_since_start < 2.0 { |
| 161 | oscillator.set_waveform(Waveform::Triangle); |
| 162 | } else if time_since_start < 3.0 { |
| 163 | oscillator.set_waveform(Waveform::Square); |
| 164 | } else if time_since_start < 4.0 { |
| 165 | oscillator.set_waveform(Waveform::Saw); |
| 166 | } else { |
| 167 | oscillator.set_waveform(Waveform::Sine); |
| 168 | } |
| 169 | process_frame(output, &mut oscillator, num_channels) |
| 170 | }, |
| 171 | err_fn, |
| 172 | None, |
| 173 | )?; |
| 174 | |
| 175 | Ok(stream) |
| 176 | } |
| 177 | |
| 178 | fn process_frame<SampleType>( |
| 179 | output: &mut [SampleType], |
| 180 | oscillator: &mut Oscillator, |
| 181 | num_channels: usize, |
| 182 | ) where |
| 183 | SampleType: Sample + FromSample<f32>, |
| 184 | { |
| 185 | for frame in output.chunks_mut(num_channels) { |
| 186 | let value: SampleType = SampleType::from_sample(oscillator.tick()); |
| 187 | |
| 188 | // copy the same value to all channels |
| 189 | for sample in frame.iter_mut() { |
| 190 | *sample = value; |
| 191 | } |
| 192 | } |
| 193 | } |