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Compute device configs for cpal

This commit is contained in:
Robbert van der Helm 2022-08-19 19:23:51 +02:00
parent ff692ee084
commit 1fc437068a

View file

@ -1,16 +1,20 @@
use anyhow::{Context, Result};
use cpal::traits::*;
use cpal::{traits::*, Device, SampleFormat, StreamConfig};
use super::super::config::WrapperConfig;
use super::Backend;
use crate::buffer::Buffer;
use crate::context::Transport;
use crate::midi::NoteEvent;
use crate::plugin::Plugin;
use crate::plugin::{AuxiliaryIOConfig, BusConfig, Plugin};
/// Uses CPAL for audio and midir for MIDI.
pub struct Cpal {
// TODO:
bus_config: BusConfig,
input_device: Option<Device>,
input_config: Option<StreamConfig>,
output_device: Device,
output_config: StreamConfig,
// TODO: MIDI
}
@ -34,7 +38,7 @@ impl Cpal {
// No input device is connected unless requested by the user to avoid feedback loops
let input_device = config
.input_device
.map(|name| -> Result<cpal::Device> {
.map(|name| -> Result<Device> {
let device = host
.input_devices()
.context("No audio input devices available")?
@ -77,6 +81,92 @@ impl Cpal {
.context("No default audio output device available")?,
};
anyhow::bail!("Not yet implemented");
let bus_config = BusConfig {
num_input_channels: config.input_channels.unwrap_or(P::DEFAULT_INPUT_CHANNELS),
num_output_channels: config.output_channels.unwrap_or(P::DEFAULT_OUTPUT_CHANNELS),
// TODO: Support these in the standalone
aux_input_busses: AuxiliaryIOConfig::default(),
aux_output_busses: AuxiliaryIOConfig::default(),
};
let requested_sample_rate = cpal::SampleRate(config.sample_rate as u32);
let requested_buffer_size = cpal::BufferSize::Fixed(config.period_size);
let input_config = input_device
.as_ref()
.map(|device| -> Result<StreamConfig> {
let input_configs: Vec<_> = device
.supported_input_configs()
.context("Could not get supported audio input configurations")?
.filter(|c| match c.buffer_size() {
cpal::SupportedBufferSize::Range { min, max } => {
c.channels() as u32 == bus_config.num_input_channels
&& (c.min_sample_rate()..=c.max_sample_rate())
.contains(&requested_sample_rate)
&& (min..=max).contains(&&config.period_size)
}
cpal::SupportedBufferSize::Unknown => false,
})
.collect();
let input_config_range = input_configs
.iter()
// Prefer floating point samples to avoid conversions
.find(|c| c.sample_format() == SampleFormat::F32)
.or_else(|| input_configs.first())
.cloned()
.with_context(|| {
format!(
"The audio input device does not support {} audio channels at a \
sample rate of {} Hz and a period size of {} samples",
bus_config.num_input_channels, config.sample_rate, config.period_size,
)
})?;
// We already checked that these settings are valid
Ok(StreamConfig {
channels: input_config_range.channels(),
sample_rate: requested_sample_rate,
buffer_size: requested_buffer_size.clone(),
})
})
.transpose()?;
let output_configs: Vec<_> = output_device
.supported_output_configs()
.context("Could not get supported audio output configurations")?
.filter(|c| match c.buffer_size() {
cpal::SupportedBufferSize::Range { min, max } => {
c.channels() as u32 == bus_config.num_output_channels
&& (c.min_sample_rate()..=c.max_sample_rate())
.contains(&requested_sample_rate)
&& (min..=max).contains(&&config.period_size)
}
cpal::SupportedBufferSize::Unknown => false,
})
.collect();
let output_config_range = output_configs
.iter()
.find(|c| c.sample_format() == SampleFormat::F32)
.or_else(|| output_configs.first())
.cloned()
.with_context(|| {
format!(
"The audio output device does not support {} audio channels at a sample rate \
of {} Hz and a period size of {} samples",
bus_config.num_output_channels, config.sample_rate, config.period_size,
)
})?;
let output_config = StreamConfig {
channels: output_config_range.channels(),
sample_rate: requested_sample_rate,
buffer_size: requested_buffer_size,
};
Ok(Cpal {
bus_config,
input_device,
input_config,
output_device,
output_config,
})
}
}