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|
extern crate asio_sys as sys;
extern crate num_traits;
use crate::host::com;
use crate::I24;
use self::num_traits::{FromPrimitive, PrimInt};
use super::Device;
use crate::{
BackendSpecificError, BufferSize, BuildStreamError, Data, InputCallbackInfo,
OutputCallbackInfo, PauseStreamError, PlayStreamError, SampleFormat, StreamConfig, StreamError,
};
use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
use std::sync::{Arc, Mutex};
use std::time::Duration;
pub struct Stream {
playing: Arc<AtomicBool>,
// Ensure the `Driver` does not terminate until the last stream is dropped.
driver: Arc<sys::Driver>,
#[allow(dead_code)]
asio_streams: Arc<Mutex<sys::AsioStreams>>,
callback_id: sys::BufferCallbackId,
driver_event_callback_id: sys::DriverEventCallbackId,
}
// Compile-time assertion that Stream is Send and Sync
crate::assert_stream_send!(Stream);
crate::assert_stream_sync!(Stream);
impl Stream {
pub fn play(&self) -> Result<(), PlayStreamError> {
self.playing.store(true, Ordering::Release);
Ok(())
}
pub fn pause(&self) -> Result<(), PauseStreamError> {
self.playing.store(false, Ordering::Release);
Ok(())
}
pub fn buffer_size(&self) -> Option<crate::FrameCount> {
let streams = self.asio_streams.lock().ok()?;
streams
.output
.as_ref()
.or(streams.input.as_ref())
.map(|s| s.buffer_size as crate::FrameCount)
}
}
impl Device {
pub fn build_input_stream_raw<D, E>(
&self,
config: StreamConfig,
sample_format: SampleFormat,
mut data_callback: D,
error_callback: E,
_timeout: Option<Duration>,
) -> Result<Stream, BuildStreamError>
where
D: FnMut(&Data, &InputCallbackInfo) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
com::com_initialized();
let description = self
.description()
.map_err(|_| BuildStreamError::DeviceNotAvailable)?;
let driver = super::GLOBAL_ASIO
.get()
.ok_or(BuildStreamError::DeviceNotAvailable)?
.load_driver(description.name())
.map_err(load_driver_err)?;
let stream_type = driver.input_data_type().map_err(build_stream_err)?;
// Ensure that the desired sample type is supported.
let expected_sample_format = super::device::convert_data_type(&stream_type)
.ok_or(BuildStreamError::StreamConfigNotSupported)?;
if sample_format != expected_sample_format {
return Err(BuildStreamError::StreamConfigNotSupported);
}
let num_channels = config.channels;
let buffer_size = self.get_or_create_input_stream(&driver, config, sample_format)?;
let cpal_num_samples = buffer_size * num_channels as usize;
// Create the buffer depending on the size of the data type.
let len_bytes = cpal_num_samples * sample_format.sample_size();
let mut interleaved = vec![0u8; len_bytes];
// Query hardware input latency (order matters: needs buffers created above).
// Wrapped in Arc<AtomicUsize> so the message callback can update it on
// kAsioLatenciesChanged without touching the buffer callback.
let hardware_input_latency = Arc::new(AtomicUsize::new(
driver
.latencies()
.map(|latencies| latencies.input.max(0) as usize)
.unwrap_or(0),
));
let driver_event_callback_id = self.add_event_callback(
&driver,
error_callback,
Arc::clone(&hardware_input_latency),
true,
);
let stream_playing = Arc::new(AtomicBool::new(false));
let playing = Arc::clone(&stream_playing);
let asio_streams = self.asio_streams.clone();
let mut current_buffer_size = buffer_size as i32;
let mut last_buffer_index: i32 = -1;
// Set the input callback.
// This is most performance critical part of the ASIO bindings.
let callback_id = driver.add_callback(move |callback_info| unsafe {
// If not playing return early.
if !playing.load(Ordering::Acquire) {
return;
}
// Guard against non-conformant drivers (e.g. Focusrite USB ASIO, ReaRoute) that
// fire the buffer callback multiple times per buffer cycle with the same buffer
// index.
if callback_info.buffer_index == last_buffer_index {
return;
}
last_buffer_index = callback_info.buffer_index;
// There is 0% chance of lock contention the host only locks when recreating streams.
let stream_lock = asio_streams.lock().unwrap();
let asio_stream = match stream_lock.input {
Some(ref asio_stream) => asio_stream,
None => return,
};
// Resize the buffer only when the driver issues a buffer size change request.
// In normal operation this branch is never taken.
if asio_stream.buffer_size != current_buffer_size {
current_buffer_size = asio_stream.buffer_size;
interleaved.resize(
current_buffer_size as usize
* num_channels as usize
* sample_format.sample_size(),
0,
);
}
let hardware_input_latency = hardware_input_latency.load(Ordering::Relaxed);
/// 1. Write from the ASIO buffer to the interleaved CPAL buffer.
/// 2. Deliver the CPAL buffer to the user callback.
#[allow(clippy::too_many_arguments)]
unsafe fn process_input_callback<A, D, F>(
data_callback: &mut D,
interleaved: &mut [u8],
asio_stream: &sys::AsioStream,
asio_info: &sys::CallbackInfo,
sample_rate: crate::SampleRate,
format: SampleFormat,
from_endianness: F,
hardware_latency_frames: usize,
) where
A: Copy,
D: FnMut(&Data, &InputCallbackInfo) + Send + 'static,
F: Fn(A) -> A,
{
// 1. Write the ASIO channels to the CPAL buffer.
let interleaved: &mut [A] = cast_slice_mut(interleaved);
let n_frames = asio_stream.buffer_size as usize;
let n_channels = interleaved.len() / n_frames;
let buffer_index = asio_info.buffer_index as usize;
for ch_ix in 0..n_channels {
let asio_channel =
asio_channel_slice::<A>(asio_stream, buffer_index, ch_ix, None);
for (frame, s_asio) in interleaved.chunks_mut(n_channels).zip(asio_channel) {
frame[ch_ix] = from_endianness(*s_asio);
}
}
// 2. Deliver the interleaved buffer to the callback.
apply_input_callback_to_data::<A, _>(
data_callback,
interleaved,
asio_info,
sample_rate,
format,
hardware_latency_frames,
);
}
match (&stream_type, sample_format) {
(&sys::AsioSampleType::ASIOSTInt16LSB, SampleFormat::I16) => {
process_input_callback::<i16, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::I16,
from_le,
hardware_input_latency,
);
}
(&sys::AsioSampleType::ASIOSTInt16MSB, SampleFormat::I16) => {
process_input_callback::<i16, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::I16,
from_be,
hardware_input_latency,
);
}
(&sys::AsioSampleType::ASIOSTFloat32LSB, SampleFormat::F32) => {
process_input_callback::<u32, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::F32,
from_le,
hardware_input_latency,
);
}
(&sys::AsioSampleType::ASIOSTFloat32MSB, SampleFormat::F32) => {
process_input_callback::<u32, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::F32,
from_be,
hardware_input_latency,
);
}
(&sys::AsioSampleType::ASIOSTInt32LSB, SampleFormat::I32) => {
process_input_callback::<i32, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::I32,
from_le,
hardware_input_latency,
);
}
(&sys::AsioSampleType::ASIOSTInt32MSB, SampleFormat::I32) => {
process_input_callback::<i32, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::I32,
from_be,
hardware_input_latency,
);
}
(&sys::AsioSampleType::ASIOSTFloat64LSB, SampleFormat::F64) => {
process_input_callback::<u64, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::F64,
from_le,
hardware_input_latency,
);
}
(&sys::AsioSampleType::ASIOSTFloat64MSB, SampleFormat::F64) => {
process_input_callback::<u64, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::F64,
from_be,
hardware_input_latency,
);
}
(&sys::AsioSampleType::ASIOSTInt24LSB, SampleFormat::I24) => {
process_input_callback_i24(
&mut data_callback,
&mut interleaved,
asio_stream,
callback_info,
config.sample_rate,
true,
hardware_input_latency,
);
}
(&sys::AsioSampleType::ASIOSTInt24MSB, SampleFormat::I24) => {
process_input_callback_i24(
&mut data_callback,
&mut interleaved,
asio_stream,
callback_info,
config.sample_rate,
false,
hardware_input_latency,
);
}
unsupported_format_pair => unreachable!(
"`build_input_stream_raw` should have returned with unsupported \
format {:?}",
unsupported_format_pair
),
}
});
let driver = Arc::new(driver);
let asio_streams = self.asio_streams.clone();
driver.start().map_err(build_stream_err)?;
Ok(Stream {
playing: stream_playing,
driver,
asio_streams,
callback_id,
driver_event_callback_id,
})
}
pub fn build_output_stream_raw<D, E>(
&self,
config: StreamConfig,
sample_format: SampleFormat,
mut data_callback: D,
error_callback: E,
_timeout: Option<Duration>,
) -> Result<Stream, BuildStreamError>
where
D: FnMut(&mut Data, &OutputCallbackInfo) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
com::com_initialized();
let description = self
.description()
.map_err(|_| BuildStreamError::DeviceNotAvailable)?;
let driver = super::GLOBAL_ASIO
.get()
.ok_or(BuildStreamError::DeviceNotAvailable)?
.load_driver(description.name())
.map_err(load_driver_err)?;
let stream_type = driver.output_data_type().map_err(build_stream_err)?;
// Ensure that the desired sample type is supported.
let expected_sample_format = super::device::convert_data_type(&stream_type)
.ok_or(BuildStreamError::StreamConfigNotSupported)?;
if sample_format != expected_sample_format {
return Err(BuildStreamError::StreamConfigNotSupported);
}
let num_channels = config.channels;
let buffer_size = self.get_or_create_output_stream(&driver, config, sample_format)?;
let cpal_num_samples = buffer_size * num_channels as usize;
// Create the buffer depending on data type.
let len_bytes = cpal_num_samples * sample_format.sample_size();
let mut interleaved = vec![0u8; len_bytes];
let current_callback_flag = self.current_callback_flag.clone();
// Query hardware output latency (order matters: needs buffers created above).
// Wrapped in Arc<AtomicUsize> so the message callback can update it on
// kAsioLatenciesChanged without touching the buffer callback.
let hardware_output_latency = Arc::new(AtomicUsize::new(
driver
.latencies()
.map(|latencies| latencies.output.max(0) as usize)
.unwrap_or(0),
));
let driver_event_callback_id = self.add_event_callback(
&driver,
error_callback,
Arc::clone(&hardware_output_latency),
false,
);
let stream_playing = Arc::new(AtomicBool::new(false));
let playing = Arc::clone(&stream_playing);
let asio_streams = self.asio_streams.clone();
let mut current_buffer_size = buffer_size as i32;
let mut last_buffer_index: i32 = -1;
let callback_id = driver.add_callback(move |callback_info| unsafe {
// If not playing, return early.
if !playing.load(Ordering::Acquire) {
return;
}
// Guard against non-conformant drivers (e.g. Focusrite USB ASIO, ReaRoute) that
// fire the buffer callback multiple times per buffer cycle with the same buffer
// index.
if callback_info.buffer_index == last_buffer_index {
return;
}
last_buffer_index = callback_info.buffer_index;
// There is 0% chance of lock contention the host only locks when recreating streams.
let mut stream_lock = asio_streams.lock().unwrap();
let asio_stream = match stream_lock.output {
Some(ref mut asio_stream) => asio_stream,
None => return,
};
// Resize the buffer only when the driver issues a buffer size change request.
// In normal operation this branch is never taken.
if asio_stream.buffer_size != current_buffer_size {
current_buffer_size = asio_stream.buffer_size;
interleaved.resize(
current_buffer_size as usize
* num_channels as usize
* sample_format.sample_size(),
0,
);
}
let hardware_output_latency = hardware_output_latency.load(Ordering::Relaxed);
// Silence the ASIO buffer that is about to be used.
//
// Check if any other callbacks have already silenced the buffer associated with
// the current callback. The flag is updated once per buffer switch.
let silence =
current_callback_flag.load(Ordering::Acquire) != callback_info.callback_flag;
if silence {
current_callback_flag.store(callback_info.callback_flag, Ordering::Release);
}
/// 1. Render the given callback to the given buffer of interleaved samples.
/// 2. If required, silence the ASIO buffer.
/// 3. Finally, write the interleaved data to the non-interleaved ASIO buffer,
/// performing endianness conversions as necessary.
#[allow(clippy::too_many_arguments)]
unsafe fn process_output_callback<A, D, F>(
data_callback: &mut D,
interleaved: &mut [u8],
silence_asio_buffer: bool,
asio_stream: &mut sys::AsioStream,
asio_info: &sys::CallbackInfo,
sample_rate: crate::SampleRate,
format: SampleFormat,
mix_samples: F,
hardware_latency_frames: usize,
) where
A: Copy,
D: FnMut(&mut Data, &OutputCallbackInfo) + Send + 'static,
F: Fn(A, A) -> A,
{
let interleaved: &mut [A] = cast_slice_mut(interleaved);
apply_output_callback_to_data::<A, _>(
data_callback,
interleaved,
asio_info,
sample_rate,
format,
hardware_latency_frames,
);
let n_channels = interleaved.len() / asio_stream.buffer_size as usize;
let buffer_index = asio_info.buffer_index as usize;
// Write interleaved samples to ASIO channels, one channel at a time.
for ch_ix in 0..n_channels {
let asio_channel =
asio_channel_slice_mut::<A>(asio_stream, buffer_index, ch_ix, None);
if silence_asio_buffer {
asio_channel.align_to_mut::<u8>().1.fill(0);
}
for (frame, s_asio) in interleaved.chunks(n_channels).zip(asio_channel) {
*s_asio = mix_samples(*s_asio, frame[ch_ix]);
}
}
}
match (sample_format, &stream_type) {
(SampleFormat::I16, &sys::AsioSampleType::ASIOSTInt16LSB) => {
process_output_callback::<i16, _, _>(
&mut data_callback,
&mut interleaved,
silence,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::I16,
|old_sample, new_sample| {
from_le(old_sample).saturating_add(new_sample).to_le()
},
hardware_output_latency,
);
}
(SampleFormat::I16, &sys::AsioSampleType::ASIOSTInt16MSB) => {
process_output_callback::<i16, _, _>(
&mut data_callback,
&mut interleaved,
silence,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::I16,
|old_sample, new_sample| {
from_be(old_sample).saturating_add(new_sample).to_be()
},
hardware_output_latency,
);
}
(SampleFormat::F32, &sys::AsioSampleType::ASIOSTFloat32LSB) => {
process_output_callback::<u32, _, _>(
&mut data_callback,
&mut interleaved,
silence,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::F32,
|old_sample, new_sample| {
(f32::from_bits(from_le(old_sample)) + f32::from_bits(new_sample))
.to_bits()
.to_le()
},
hardware_output_latency,
);
}
(SampleFormat::F32, &sys::AsioSampleType::ASIOSTFloat32MSB) => {
process_output_callback::<u32, _, _>(
&mut data_callback,
&mut interleaved,
silence,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::F32,
|old_sample, new_sample| {
(f32::from_bits(from_be(old_sample)) + f32::from_bits(new_sample))
.to_bits()
.to_be()
},
hardware_output_latency,
);
}
(SampleFormat::I32, &sys::AsioSampleType::ASIOSTInt32LSB) => {
process_output_callback::<i32, _, _>(
&mut data_callback,
&mut interleaved,
silence,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::I32,
|old_sample, new_sample| {
from_le(old_sample).saturating_add(new_sample).to_le()
},
hardware_output_latency,
);
}
(SampleFormat::I32, &sys::AsioSampleType::ASIOSTInt32MSB) => {
process_output_callback::<i32, _, _>(
&mut data_callback,
&mut interleaved,
silence,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::I32,
|old_sample, new_sample| {
from_be(old_sample).saturating_add(new_sample).to_be()
},
hardware_output_latency,
);
}
(SampleFormat::F64, &sys::AsioSampleType::ASIOSTFloat64LSB) => {
process_output_callback::<u64, _, _>(
&mut data_callback,
&mut interleaved,
silence,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::F64,
|old_sample, new_sample| {
(f64::from_bits(from_le(old_sample)) + f64::from_bits(new_sample))
.to_bits()
.to_le()
},
hardware_output_latency,
);
}
(SampleFormat::F64, &sys::AsioSampleType::ASIOSTFloat64MSB) => {
process_output_callback::<u64, _, _>(
&mut data_callback,
&mut interleaved,
silence,
asio_stream,
callback_info,
config.sample_rate,
SampleFormat::F64,
|old_sample, new_sample| {
(f64::from_bits(from_be(old_sample)) + f64::from_bits(new_sample))
.to_bits()
.to_be()
},
hardware_output_latency,
);
}
(SampleFormat::I24, &sys::AsioSampleType::ASIOSTInt24LSB) => {
process_output_callback_i24::<_>(
&mut data_callback,
&mut interleaved,
silence,
true,
asio_stream,
callback_info,
config.sample_rate,
hardware_output_latency,
);
}
(SampleFormat::I24, &sys::AsioSampleType::ASIOSTInt24MSB) => {
process_output_callback_i24::<_>(
&mut data_callback,
&mut interleaved,
silence,
false,
asio_stream,
callback_info,
config.sample_rate,
hardware_output_latency,
);
}
unsupported_format_pair => unreachable!(
"`build_output_stream_raw` should have returned with unsupported \
format {:?}",
unsupported_format_pair
),
}
});
let driver = Arc::new(driver);
let asio_streams = self.asio_streams.clone();
driver.start().map_err(build_stream_err)?;
Ok(Stream {
playing: stream_playing,
driver,
asio_streams,
callback_id,
driver_event_callback_id,
})
}
/// Create a new CPAL Input Stream.
///
/// If there is no existing ASIO Input Stream it will be created.
///
/// On success, the buffer size of the stream is returned.
fn get_or_create_input_stream(
&self,
driver: &sys::Driver,
config: StreamConfig,
sample_format: SampleFormat,
) -> Result<usize, BuildStreamError> {
let num_asio_channels = self
.default_input_config()
.map_err(|_| BuildStreamError::StreamConfigNotSupported)?
.channels;
check_config(driver, config, sample_format, num_asio_channels)?;
let num_channels = config.channels as usize;
let mut streams = self.asio_streams.lock().unwrap();
let buffer_size = match config.buffer_size {
BufferSize::Fixed(v) => Some(v as i32),
BufferSize::Default => None,
};
// Either create a stream if thers none or had back the
// size of the current one.
match streams.input {
Some(ref input) => Ok(input.buffer_size as usize),
None => {
let output = streams.output.take();
driver
.prepare_input_stream(output, num_channels, buffer_size)
.map(|new_streams| {
let bs = match new_streams.input {
Some(ref inp) => inp.buffer_size as usize,
None => unreachable!(),
};
*streams = new_streams;
bs
})
.map_err(|_| BuildStreamError::DeviceNotAvailable)
}
}
}
/// Create a new CPAL Output Stream.
///
/// If there is no existing ASIO Output Stream it will be created.
fn get_or_create_output_stream(
&self,
driver: &sys::Driver,
config: StreamConfig,
sample_format: SampleFormat,
) -> Result<usize, BuildStreamError> {
let num_asio_channels = self
.default_output_config()
.map_err(|_| BuildStreamError::StreamConfigNotSupported)?
.channels;
check_config(driver, config, sample_format, num_asio_channels)?;
let num_channels = config.channels as usize;
let mut streams = self.asio_streams.lock().unwrap();
let buffer_size = match config.buffer_size {
BufferSize::Fixed(v) => Some(v as i32),
BufferSize::Default => None,
};
// Either create a stream if thers none or had back the
// size of the current one.
match streams.output {
Some(ref output) => Ok(output.buffer_size as usize),
None => {
let input = streams.input.take();
driver
.prepare_output_stream(input, num_channels, buffer_size)
.map(|new_streams| {
let bs = match new_streams.output {
Some(ref out) => out.buffer_size as usize,
None => unreachable!(),
};
*streams = new_streams;
bs
})
.map_err(|_| BuildStreamError::DeviceNotAvailable)
}
}
}
fn add_event_callback<E>(
&self,
driver: &sys::Driver,
error_callback: E,
hardware_latency: Arc<AtomicUsize>,
is_input: bool,
) -> sys::DriverEventCallbackId
where
E: FnMut(StreamError) + Send + 'static,
{
let error_callback_shared = Arc::new(Mutex::new(error_callback));
let configured_sample_rate = driver.sample_rate().ok().filter(|&r| r > 0.0);
let driver_for_latency = driver.clone();
let asio_streams_for_event = self.asio_streams.clone();
driver.add_event_callback(move |event| {
match event {
sys::AsioDriverEvent::Message {
selector: msg,
value,
} => match msg {
sys::AsioMessageSelectors::kAsioSelectorSupported => {
// Signal which selectors this stream opts into.
matches!(
sys::AsioMessageSelectors::from_i64(value as i64),
Some(sys::AsioMessageSelectors::kAsioBufferSizeChange)
)
}
sys::AsioMessageSelectors::kAsioResetRequest => {
if let Ok(mut cb) = error_callback_shared.lock() {
cb(StreamError::StreamInvalidated);
}
false
}
sys::AsioMessageSelectors::kAsioResyncRequest => {
if let Ok(mut cb) = error_callback_shared.lock() {
cb(StreamError::BufferUnderrun);
}
false
}
sys::AsioMessageSelectors::kAsioLatenciesChanged => {
if let Ok(latencies) = driver_for_latency.latencies() {
let latency = if is_input {
latencies.input
} else {
latencies.output
};
hardware_latency.store(latency.max(0) as usize, Ordering::Relaxed);
}
false
}
sys::AsioMessageSelectors::kAsioBufferSizeChange => {
if value > 0 {
if let Ok(mut streams) = asio_streams_for_event.lock() {
let stream = if is_input {
streams.input.as_mut()
} else {
streams.output.as_mut()
};
if let Some(s) = stream {
s.buffer_size = value;
}
}
}
true
}
_ => false,
},
sys::AsioDriverEvent::SampleRateChanged(new_rate) => {
if let Some(rate) = configured_sample_rate {
if (new_rate - rate).abs() >= 1.0 {
if let Ok(mut cb) = error_callback_shared.lock() {
cb(StreamError::StreamInvalidated);
}
}
}
false
}
}
})
}
}
impl Drop for Stream {
fn drop(&mut self) {
self.driver.remove_callback(self.callback_id);
self.driver
.remove_event_callback(self.driver_event_callback_id);
}
}
// Convert the given duration in frames at the given sample rate to a `std::time::Duration`.
#[inline]
fn frames_to_duration(frames: usize, rate: crate::SampleRate) -> std::time::Duration {
let secsf = frames as f64 / rate as f64;
let secs = secsf as u64;
let nanos = ((secsf - secs as f64) * 1_000_000_000.0) as u32;
std::time::Duration::new(secs, nanos)
}
/// Check whether or not the desired config is supported by the stream.
///
/// Checks sample rate, data type, number of channels, and buffer size.
fn check_config(
driver: &sys::Driver,
config: StreamConfig,
sample_format: SampleFormat,
num_asio_channels: u16,
) -> Result<(), BuildStreamError> {
let StreamConfig {
channels,
sample_rate,
buffer_size,
} = config;
// Validate buffer size if `Fixed` is specified. This is necessary because ASIO's
// `create_buffers` only validates the upper bound (returns `InvalidBufferSize` if > max) but
// does NOT validate the lower bound. Passing a buffer size below min would be accepted but
// behavior is unspecified.
if let BufferSize::Fixed(requested_size) = buffer_size {
let range = driver.buffersize_range().map_err(build_stream_err)?;
let requested_size_i32 = requested_size as i32;
if !(range.min..=range.max).contains(&requested_size_i32) {
return Err(BuildStreamError::StreamConfigNotSupported);
}
}
// Try and set the sample rate to what the user selected.
let sample_rate = sample_rate.into();
if sample_rate != driver.sample_rate().map_err(build_stream_err)? {
if driver
.can_sample_rate(sample_rate)
.map_err(build_stream_err)?
{
driver
.set_sample_rate(sample_rate)
.map_err(build_stream_err)?;
} else {
return Err(BuildStreamError::StreamConfigNotSupported);
}
}
// unsigned formats are not supported by asio
match sample_format {
SampleFormat::I16 | SampleFormat::I24 | SampleFormat::I32 | SampleFormat::F32 => (),
_ => return Err(BuildStreamError::StreamConfigNotSupported),
}
if channels > num_asio_channels {
return Err(BuildStreamError::StreamConfigNotSupported);
}
Ok(())
}
/// Cast a byte slice into a mutable slice of desired type.
///
/// Safety: it's up to the caller to ensure that the input slice has valid bit representations.
unsafe fn cast_slice_mut<T>(v: &mut [u8]) -> &mut [T] {
debug_assert!(v.len() % std::mem::size_of::<T>() == 0);
std::slice::from_raw_parts_mut(v.as_mut_ptr() as *mut T, v.len() / std::mem::size_of::<T>())
}
/// Helper function to convert from little endianness.
fn from_le<T: PrimInt>(t: T) -> T {
T::from_le(t)
}
/// Helper function to convert from little endianness.
fn from_be<T: PrimInt>(t: T) -> T {
T::from_be(t)
}
/// Shorthand for retrieving the asio buffer slice associated with a channel.
///
/// The channel length is automatically inferred from the buffer size or some
/// value can be passed to enforce a certain length (for odd sized sample formats)
unsafe fn asio_channel_slice<T>(
asio_stream: &sys::AsioStream,
buffer_index: usize,
channel_index: usize,
requested_channel_length: Option<usize>,
) -> &[T] {
let channel_length = requested_channel_length.unwrap_or(asio_stream.buffer_size as usize);
let buff_ptr: *const T =
asio_stream.buffer_infos[channel_index].buffers[buffer_index] as *const _;
std::slice::from_raw_parts(buff_ptr, channel_length)
}
/// Shorthand for retrieving the asio buffer slice associated with a channel.
///
/// The channel length is automatically inferred from the buffer size or some
/// value can be passed to enforce a certain length (for odd sized sample formats)
unsafe fn asio_channel_slice_mut<T>(
asio_stream: &mut sys::AsioStream,
buffer_index: usize,
channel_index: usize,
requested_channel_length: Option<usize>,
) -> &mut [T] {
let channel_length = requested_channel_length.unwrap_or(asio_stream.buffer_size as usize);
let buff_ptr: *mut T = asio_stream.buffer_infos[channel_index].buffers[buffer_index] as *mut _;
std::slice::from_raw_parts_mut(buff_ptr, channel_length)
}
fn load_driver_err(e: sys::LoadDriverError) -> BuildStreamError {
match e {
sys::LoadDriverError::LoadDriverFailed | sys::LoadDriverError::DriverAlreadyExists => {
BuildStreamError::DeviceNotAvailable
}
sys::LoadDriverError::InitializationFailed(asio_err) => build_stream_err(asio_err),
}
}
fn build_stream_err(e: sys::AsioError) -> BuildStreamError {
match e {
sys::AsioError::NoDrivers | sys::AsioError::HardwareMalfunction => {
BuildStreamError::DeviceNotAvailable
}
sys::AsioError::InvalidInput | sys::AsioError::BadMode => BuildStreamError::InvalidArgument,
err => {
let description = format!("{}", err);
BackendSpecificError { description }.into()
}
}
}
/// Convert i24 bytes to i32
fn i24_bytes_to_i32(i24_bytes: &[u8; 3], little_endian: bool) -> i32 {
let sample = if little_endian {
i32::from_le_bytes([i24_bytes[0], i24_bytes[1], i24_bytes[2], 0u8])
} else {
i32::from_le_bytes([i24_bytes[2], i24_bytes[1], i24_bytes[0], 0u8])
};
if sample & 0x800000 != 0 {
sample | -0x1000000
} else {
sample
}
}
#[allow(clippy::too_many_arguments)]
unsafe fn process_output_callback_i24<D>(
data_callback: &mut D,
interleaved: &mut [u8],
silence_asio_buffer: bool,
little_endian: bool,
asio_stream: &mut sys::AsioStream,
asio_info: &sys::CallbackInfo,
sample_rate: crate::SampleRate,
hardware_latency_frames: usize,
) where
D: FnMut(&mut Data, &OutputCallbackInfo) + Send + 'static,
{
let format = SampleFormat::I24;
let interleaved: &mut [I24] = cast_slice_mut(interleaved);
apply_output_callback_to_data::<I24, _>(
data_callback,
interleaved,
asio_info,
sample_rate,
format,
hardware_latency_frames,
);
// Size of samples in the ASIO buffer (has to be 3 in this case)
let asio_sample_size_bytes = 3;
let n_channels = interleaved.len() / asio_stream.buffer_size as usize;
let buffer_index = asio_info.buffer_index as usize;
// Write interleaved samples to ASIO channels, one channel at a time.
for ch_ix in 0..n_channels {
// Take channel as u8 array ([u8; 3] packets to represent i24)
let asio_channel = asio_channel_slice_mut(
asio_stream,
buffer_index,
ch_ix,
Some(asio_stream.buffer_size as usize * asio_sample_size_bytes),
);
if silence_asio_buffer {
asio_channel.align_to_mut::<u8>().1.fill(0);
}
// Fill in every channel from the interleaved vector
for (channel_sample, sample_in_buffer) in asio_channel
.chunks_mut(asio_sample_size_bytes)
.zip(interleaved.iter().skip(ch_ix).step_by(n_channels))
{
// Add samples from buffer if no silence was applied, otherwise just overwrite
let result = if silence_asio_buffer {
sample_in_buffer.inner()
} else {
let sample = i24_bytes_to_i32(
&[channel_sample[0], channel_sample[1], channel_sample[2]],
little_endian,
);
(sample_in_buffer.inner() + sample).clamp(-8388608, 8388607)
};
let bytes = result.to_le_bytes();
if little_endian {
channel_sample[0] = bytes[0];
channel_sample[1] = bytes[1];
channel_sample[2] = bytes[2];
} else {
channel_sample[2] = bytes[0];
channel_sample[1] = bytes[1];
channel_sample[0] = bytes[2];
}
}
}
}
unsafe fn process_input_callback_i24<D>(
data_callback: &mut D,
interleaved: &mut [u8],
asio_stream: &sys::AsioStream,
asio_info: &sys::CallbackInfo,
sample_rate: crate::SampleRate,
little_endian: bool,
hardware_latency_frames: usize,
) where
D: FnMut(&Data, &InputCallbackInfo) + Send + 'static,
{
let format = SampleFormat::I24;
// 1. Write the ASIO channels to the CPAL buffer.
let interleaved: &mut [I24] = cast_slice_mut(interleaved);
let n_frames = asio_stream.buffer_size as usize;
let n_channels = interleaved.len() / n_frames;
let buffer_index = asio_info.buffer_index as usize;
let asio_sample_size_bytes = 3;
for ch_ix in 0..n_channels {
let asio_channel = asio_channel_slice::<u8>(
asio_stream,
buffer_index,
ch_ix,
Some(n_frames * asio_sample_size_bytes),
);
for (channel_sample, sample_in_buffer) in asio_channel
.chunks(asio_sample_size_bytes)
.zip(interleaved.iter_mut().skip(ch_ix).step_by(n_channels))
{
let sample = i24_bytes_to_i32(
&[channel_sample[0], channel_sample[1], channel_sample[2]],
little_endian,
);
*sample_in_buffer = I24::new(sample).unwrap();
}
}
// 2. Deliver the interleaved buffer to the callback.
apply_input_callback_to_data::<I24, _>(
data_callback,
interleaved,
asio_info,
sample_rate,
format,
hardware_latency_frames,
);
}
/// Apply the output callback to the interleaved buffer.
unsafe fn apply_output_callback_to_data<A, D>(
data_callback: &mut D,
interleaved: &mut [A],
asio_info: &sys::CallbackInfo,
sample_rate: crate::SampleRate,
sample_format: SampleFormat,
hardware_latency_frames: usize,
) where
A: Copy,
D: FnMut(&mut Data, &OutputCallbackInfo) + Send + 'static,
{
let mut data = Data::from_parts(
interleaved.as_mut_ptr() as *mut (),
interleaved.len(),
sample_format,
);
let callback = crate::StreamInstant::from_nanos_i128(asio_info.system_time as i128)
.expect("`system_time` out of range of `StreamInstant` representation");
let delay = frames_to_duration(hardware_latency_frames, sample_rate);
let playback = callback
.add(delay)
.expect("`playback` occurs beyond representation supported by `StreamInstant`");
let timestamp = crate::OutputStreamTimestamp { callback, playback };
let info = OutputCallbackInfo { timestamp };
data_callback(&mut data, &info);
}
/// Apply the input callback to the interleaved buffer.
unsafe fn apply_input_callback_to_data<A, D>(
data_callback: &mut D,
interleaved: &mut [A],
asio_info: &sys::CallbackInfo,
sample_rate: crate::SampleRate,
format: SampleFormat,
hardware_latency_frames: usize,
) where
A: Copy,
D: FnMut(&Data, &InputCallbackInfo) + Send + 'static,
{
let data = Data::from_parts(
interleaved.as_mut_ptr() as *mut (),
interleaved.len(),
format,
);
let callback = crate::StreamInstant::from_nanos_i128(asio_info.system_time as i128)
.expect("`system_time` out of range of `StreamInstant` representation");
let delay = frames_to_duration(hardware_latency_frames, sample_rate);
let capture = callback
.sub(delay)
.expect("`capture` occurs before origin of alsa `StreamInstant`");
let timestamp = crate::InputStreamTimestamp { callback, capture };
let info = InputCallbackInfo { timestamp };
data_callback(&data, &info);
}
|