Merge pull request #3 from mitchmindtree/remove-unknown-buffer-type-alt

An alternative approach to removing `UnknownBufferType`
This commit is contained in:
mitchmindtree 2020-01-20 18:21:25 +01:00 committed by GitHub
commit d7d82ac863
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GPG Key ID: 4AEE18F83AFDEB23
14 changed files with 329 additions and 371 deletions

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@ -19,27 +19,15 @@ fn main() -> Result<(), anyhow::Error> {
(sample_clock * 440.0 * 2.0 * 3.141592 / sample_rate).sin()
};
let err_fn = |err| {
eprintln!("an error occurred on stream: {}", err);
let err_fn = |err| eprintln!("an error occurred on stream: {}", err);
let data_fn = move |data: &mut cpal::Data| match data.sample_format() {
cpal::SampleFormat::F32 => write_data::<f32>(data, channels, &mut next_value),
cpal::SampleFormat::I16 => write_data::<i16>(data, channels, &mut next_value),
cpal::SampleFormat::U16 => write_data::<u16>(data, channels, &mut next_value),
};
let stream = match format.data_type {
cpal::SampleFormat::F32 => device.build_output_stream(
&format,
move |mut data| write_data::<f32>(&mut *data, channels, &mut next_value),
err_fn,
),
cpal::SampleFormat::I16 => device.build_output_stream(
&format,
move |mut data| write_data::<i16>(&mut *data, channels, &mut next_value),
err_fn,
),
cpal::SampleFormat::U16 => device.build_output_stream(
&format,
move |mut data| write_data::<u16>(&mut *data, channels, &mut next_value),
err_fn,
),
}?;
let stream = device.build_output_stream(&format, data_fn, err_fn)?;
stream.play()?;
@ -48,10 +36,11 @@ fn main() -> Result<(), anyhow::Error> {
Ok(())
}
fn write_data<T>(output: &mut [T], channels: usize, next_sample: &mut dyn FnMut() -> f32)
fn write_data<T>(output: &mut cpal::Data, channels: usize, next_sample: &mut dyn FnMut() -> f32)
where
T: cpal::Sample,
{
let output = output.as_slice_mut::<T>().expect("unexpected sample type");
for frame in output.chunks_mut(channels) {
let value: T = cpal::Sample::from::<f32>(&next_sample());
for sample in frame.iter_mut() {

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@ -47,46 +47,40 @@ fn main() -> Result<(), anyhow::Error> {
producer.push(0.0).unwrap();
}
let input_data_fn = move |data: &cpal::Data| {
let mut output_fell_behind = false;
let data = data.as_slice::<f32>().expect("unexpected sample type");
for &sample in data {
if producer.push(sample).is_err() {
output_fell_behind = true;
}
}
if output_fell_behind {
eprintln!("output stream fell behind: try increasing latency");
}
};
let output_data_fn = move |data: &mut cpal::Data| {
let mut input_fell_behind = None;
let data = data.as_slice_mut::<f32>().expect("unexpected sample type");
for sample in data {
*sample = match consumer.pop() {
Ok(s) => s,
Err(err) => {
input_fell_behind = Some(err);
0.0
},
};
}
if let Some(err) = input_fell_behind {
eprintln!("input stream fell behind: {:?}: try increasing latency", err);
}
};
// Build streams.
println!("Attempting to build both streams with `{:?}`.", format);
let input_stream = input_device.build_input_stream(
&format,
move |data| {
let mut output_fell_behind = false;
for &sample in data.iter() {
if producer.push(sample).is_err() {
output_fell_behind = true;
}
}
if output_fell_behind {
eprintln!("output stream fell behind: try increasing latency");
}
},
|err| {
eprintln!("an error occurred on stream: {}", err);
},
)?;
let output_stream = output_device.build_output_stream(
&format,
move |mut data| {
let mut input_fell_behind = None;
for sample in data.iter_mut() {
*sample = match consumer.pop() {
Ok(s) => s,
Err(err) => {
input_fell_behind = Some(err);
0.0
},
};
}
if let Some(err) = input_fell_behind {
eprintln!("input stream fell behind: {:?}: try increasing latency", err);
}
},
move |err| {
eprintln!("an error occurred on output stream: {}", err);
},
)?;
let input_stream = input_device.build_input_stream(&format, input_data_fn, err_fn)?;
let output_stream = output_device.build_output_stream(&format, output_data_fn, err_fn)?;
println!("Successfully built streams.");
// Play the streams.
@ -105,3 +99,7 @@ fn main() -> Result<(), anyhow::Error> {
println!("Done!");
Ok(())
}
fn err_fn(err: cpal::StreamError) {
eprintln!("an error occurred on stream: {}", err);
}

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@ -40,23 +40,15 @@ fn main() -> Result<(), anyhow::Error> {
eprintln!("an error occurred on stream: {}", err);
};
let stream = match format.data_type {
cpal::SampleFormat::F32 => device.build_input_stream(
&format,
move |data| write_input_data::<f32, f32>(&*data, &writer_2),
err_fn,
),
cpal::SampleFormat::I16 => device.build_input_stream(
&format,
move |data| write_input_data::<i16, i16>(&*data, &writer_2),
err_fn,
),
cpal::SampleFormat::U16 => device.build_input_stream(
&format,
move |data| write_input_data::<u16, i16>(&*data, &writer_2),
err_fn,
),
}?;
let data_fn = move |data: &cpal::Data| {
match data.sample_format() {
cpal::SampleFormat::F32 => write_input_data::<f32, f32>(data, &writer_2),
cpal::SampleFormat::I16 => write_input_data::<i16, i16>(data, &writer_2),
cpal::SampleFormat::U16 => write_input_data::<u16, i16>(data, &writer_2),
}
};
let stream = device.build_input_stream(&format, data_fn, err_fn)?;
stream.play()?;
@ -87,11 +79,12 @@ fn wav_spec_from_format(format: &cpal::Format) -> hound::WavSpec {
type WavWriterHandle = Arc<Mutex<Option<hound::WavWriter<BufWriter<File>>>>>;
fn write_input_data<T, U>(input: &[T], writer: &WavWriterHandle)
fn write_input_data<T, U>(input: &cpal::Data, writer: &WavWriterHandle)
where
T: cpal::Sample,
U: cpal::Sample + hound::Sample,
{
let input = input.as_slice::<T>().expect("unexpected sample format");
if let Ok(mut guard) = writer.try_lock() {
if let Some(writer) = guard.as_mut() {
for &sample in input.iter() {

View File

@ -5,15 +5,13 @@ use crate::{
BackendSpecificError,
BuildStreamError,
ChannelCount,
Data,
DefaultFormatError,
DeviceNameError,
DevicesError,
Format,
InputData,
OutputData,
PauseStreamError,
PlayStreamError,
Sample,
SampleFormat,
SampleRate,
StreamError,
@ -90,37 +88,31 @@ impl DeviceTrait for Device {
Device::default_output_format(self)
}
fn build_input_stream<T, D, E>(
fn build_input_stream<D, E>(
&self,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
// TODO: Consider removing `data_type` field from `Format` and removing this.
assert_eq!(format.data_type, T::FORMAT, "sample format mismatch");
let stream_inner = self.build_stream_inner(format, alsa::SND_PCM_STREAM_CAPTURE)?;
let stream = Stream::new_input(Arc::new(stream_inner), data_callback, error_callback);
Ok(stream)
}
fn build_output_stream<T, D, E>(
fn build_output_stream<D, E>(
&self,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
// TODO: Consider removing `data_type` field from `Format` and removing this.
assert_eq!(format.data_type, T::FORMAT, "sample format mismatch");
let stream_inner = self.build_stream_inner(format, alsa::SND_PCM_STREAM_PLAYBACK)?;
let stream = Stream::new_output(Arc::new(stream_inner), data_callback, error_callback);
Ok(stream)
@ -564,14 +556,12 @@ struct StreamWorkerContext {
buffer: Vec<u8>,
}
fn input_stream_worker<T>(
fn input_stream_worker(
rx: TriggerReceiver,
stream: &StreamInner,
data_callback: &mut (dyn FnMut(InputData<T>) + Send + 'static),
data_callback: &mut (dyn FnMut(&Data) + Send + 'static),
error_callback: &mut (dyn FnMut(StreamError) + Send + 'static),
) where
T: Sample,
{
) {
let mut ctxt = StreamWorkerContext::default();
loop {
match poll_descriptors_and_prepare_buffer(&rx, stream, &mut ctxt, error_callback) {
@ -583,7 +573,7 @@ fn input_stream_worker<T>(
StreamType::Input,
"expected input stream, but polling descriptors indicated output",
);
process_input::<T>(
process_input(
stream,
&mut ctxt.buffer,
available_frames,
@ -595,14 +585,12 @@ fn input_stream_worker<T>(
}
}
fn output_stream_worker<T>(
fn output_stream_worker(
rx: TriggerReceiver,
stream: &StreamInner,
data_callback: &mut (dyn FnMut(OutputData<T>) + Send + 'static),
data_callback: &mut (dyn FnMut(&mut Data) + Send + 'static),
error_callback: &mut (dyn FnMut(StreamError) + Send + 'static),
) where
T: Sample,
{
) {
let mut ctxt = StreamWorkerContext::default();
loop {
match poll_descriptors_and_prepare_buffer(&rx, stream, &mut ctxt, error_callback) {
@ -614,7 +602,7 @@ fn output_stream_worker<T>(
StreamType::Output,
"expected output stream, but polling descriptors indicated input",
);
process_output::<T>(
process_output(
stream,
&mut ctxt.buffer,
available_frames,
@ -729,15 +717,13 @@ fn poll_descriptors_and_prepare_buffer(
}
// Read input data from ALSA and deliver it to the user.
fn process_input<T>(
fn process_input(
stream: &StreamInner,
buffer: &mut [u8],
available_frames: usize,
data_callback: &mut (dyn FnMut(InputData<T>) + Send + 'static),
data_callback: &mut (dyn FnMut(&Data) + Send + 'static),
error_callback: &mut dyn FnMut(StreamError),
) where
T: Sample,
{
) {
let result = unsafe {
alsa::snd_pcm_readi(
stream.channel,
@ -750,28 +736,34 @@ fn process_input<T>(
error_callback(BackendSpecificError { description }.into());
return;
}
let buffer = unsafe { cast_input_buffer::<T>(buffer) };
let input_data = InputData { buffer };
data_callback(input_data);
let sample_format = stream.sample_format;
let data = buffer.as_mut_ptr() as *mut ();
let len = buffer.len() / sample_format.sample_size();
let data = unsafe {
Data::from_parts(data, len, sample_format)
};
data_callback(&data);
}
// Request data from the user's function and write it via ALSA.
//
// Returns `true`
fn process_output<T>(
fn process_output(
stream: &StreamInner,
buffer: &mut [u8],
available_frames: usize,
data_callback: &mut (dyn FnMut(OutputData<T>) + Send + 'static),
data_callback: &mut (dyn FnMut(&mut Data) + Send + 'static),
error_callback: &mut dyn FnMut(StreamError),
) where
T: Sample,
{
) {
{
// We're now sure that we're ready to write data.
let buffer = unsafe { cast_output_buffer::<T>(buffer) };
let output_data = OutputData { buffer };
data_callback(output_data);
let sample_format = stream.sample_format;
let data = buffer.as_mut_ptr() as *mut ();
let len = buffer.len() / sample_format.sample_size();
let mut data = unsafe {
Data::from_parts(data, len, sample_format)
};
data_callback(&mut data);
}
loop {
let result = unsafe {
@ -805,21 +797,20 @@ fn process_output<T>(
}
impl Stream {
fn new_input<T, D, E>(
fn new_input<D, E>(
inner: Arc<StreamInner>,
mut data_callback: D,
mut error_callback: E,
) -> Stream
where
T: Sample,
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
let (tx, rx) = trigger();
// Clone the handle for passing into worker thread.
let stream = inner.clone();
let thread = thread::spawn(move || {
input_stream_worker::<T>(rx, &*stream, &mut data_callback, &mut error_callback);
input_stream_worker(rx, &*stream, &mut data_callback, &mut error_callback);
});
Stream {
thread: Some(thread),
@ -828,21 +819,20 @@ impl Stream {
}
}
fn new_output<T, D, E>(
fn new_output<D, E>(
inner: Arc<StreamInner>,
mut data_callback: D,
mut error_callback: E,
) -> Stream
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
let (tx, rx) = trigger();
// Clone the handle for passing into worker thread.
let stream = inner.clone();
let thread = thread::spawn(move || {
output_stream_worker::<T>(rx, &*stream, &mut data_callback, &mut error_callback);
output_stream_worker(rx, &*stream, &mut data_callback, &mut error_callback);
});
Stream {
thread: Some(thread),
@ -1080,17 +1070,3 @@ fn check_errors(err: libc::c_int) -> Result<(), String> {
Ok(())
}
/// Cast a byte slice into a (immutable) slice of desired type.
/// Safety: it's up to the caller to ensure that the input slice has valid bit representations.
unsafe fn cast_input_buffer<T>(v: &[u8]) -> &[T] {
debug_assert!(v.len() % std::mem::size_of::<T>() == 0);
std::slice::from_raw_parts(v.as_ptr() as *const T, v.len() / std::mem::size_of::<T>())
}
/// 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_output_buffer<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>())
}

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@ -3,15 +3,13 @@ extern crate parking_lot;
use crate::{
BuildStreamError,
Data,
DefaultFormatError,
DeviceNameError,
DevicesError,
Format,
InputData,
OutputData,
PauseStreamError,
PlayStreamError,
Sample,
StreamError,
SupportedFormatsError,
};
@ -91,29 +89,27 @@ impl DeviceTrait for Device {
Device::default_output_format(self)
}
fn build_input_stream<T, D, E>(
fn build_input_stream<D, E>(
&self,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static
{
Device::build_input_stream(self, format, data_callback, error_callback)
}
fn build_output_stream<T, D, E>(
fn build_output_stream<D, E>(
&self,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static
{
Device::build_output_stream(self, format, data_callback, error_callback)

View File

@ -9,9 +9,8 @@ use std::sync::Arc;
use super::parking_lot::Mutex;
use BackendSpecificError;
use BuildStreamError;
use Data;
use Format;
use InputData;
use OutputData;
use PauseStreamError;
use PlayStreamError;
use Sample;
@ -58,18 +57,16 @@ impl Stream {
}
impl Device {
pub fn build_input_stream<T, D, E>(
pub fn build_input_stream<D, E>(
&self,
format: &Format,
mut data_callback: D,
_error_callback: E,
) -> Result<Stream, BuildStreamError>
where
T: Sample,
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
assert_eq!(format.data_type, T::FORMAT, "sample type does not match `format.data_type`");
let stream_type = self.driver.input_data_type().map_err(build_stream_err)?;
// Ensure that the desired sample type is supported.
@ -118,7 +115,7 @@ impl Device {
where
A: AsioSample,
B: Sample,
D: FnMut(InputData<B>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
F: Fn(A) -> A,
{
// 1. Write the ASIO channels to the CPAL buffer.
@ -132,13 +129,15 @@ impl Device {
}
// 2. Deliver the interleaved buffer to the callback.
let data = InputData { buffer: interleaved };
callback(data);
let data = interleaved.as_mut_ptr() as *mut ();
let len = interleaved.len();
let data = Data::from_parts(data, len, B::FORMAT);
callback(&data);
}
match (&stream_type, data_type) {
(&sys::AsioSampleType::ASIOSTInt16LSB, SampleFormat::I16) => {
process_input_callback::<i16, T, _, _>(
process_input_callback::<i16, i16, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
@ -147,7 +146,7 @@ impl Device {
);
}
(&sys::AsioSampleType::ASIOSTInt16MSB, SampleFormat::I16) => {
process_input_callback::<i16, T, _, _>(
process_input_callback::<i16, i16, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
@ -160,7 +159,7 @@ impl Device {
// trait for the `to_le` and `to_be` methods, but this does not support floats.
(&sys::AsioSampleType::ASIOSTFloat32LSB, SampleFormat::F32) |
(&sys::AsioSampleType::ASIOSTFloat32MSB, SampleFormat::F32) => {
process_input_callback::<f32, T, _, _>(
process_input_callback::<f32, f32, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
@ -173,7 +172,7 @@ impl Device {
// `process_output_callback` function above by removing the unnecessary sample
// conversion function.
(&sys::AsioSampleType::ASIOSTInt32LSB, SampleFormat::I16) => {
process_input_callback::<i32, T, _, _>(
process_input_callback::<i32, i16, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
@ -182,7 +181,7 @@ impl Device {
);
}
(&sys::AsioSampleType::ASIOSTInt32MSB, SampleFormat::I16) => {
process_input_callback::<i32, T, _, _>(
process_input_callback::<i32, i16, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
@ -194,7 +193,7 @@ impl Device {
// trait for the `to_le` and `to_be` methods, but this does not support floats.
(&sys::AsioSampleType::ASIOSTFloat64LSB, SampleFormat::F32) |
(&sys::AsioSampleType::ASIOSTFloat64MSB, SampleFormat::F32) => {
process_input_callback::<f64, T, _, _>(
process_input_callback::<f64, f32, _, _>(
&mut data_callback,
&mut interleaved,
asio_stream,
@ -224,18 +223,16 @@ impl Device {
})
}
pub fn build_output_stream<T, D, E>(
pub fn build_output_stream<D, E>(
&self,
format: &Format,
mut data_callback: D,
_error_callback: E,
) -> Result<Stream, BuildStreamError>
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
assert_eq!(format.data_type, T::FORMAT, "sample type does not match `format.data_type`");
let stream_type = self.driver.output_data_type().map_err(build_stream_err)?;
// Ensure that the desired sample type is supported.
@ -308,12 +305,15 @@ impl Device {
where
A: Sample,
B: AsioSample,
D: FnMut(OutputData<A>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
F: Fn(B) -> B,
{
// 1. Render interleaved buffer from callback.
let interleaved: &mut [A] = cast_slice_mut(interleaved);
callback(OutputData { buffer: interleaved });
let data = interleaved.as_mut_ptr() as *mut ();
let len = interleaved.len();
let mut data = Data::from_parts(data, len, A::FORMAT);
callback(&mut data);
// 2. Silence ASIO channels if necessary.
let n_channels = interleaved.len() / asio_stream.buffer_size as usize;
@ -337,7 +337,7 @@ impl Device {
match (data_type, &stream_type) {
(SampleFormat::I16, &sys::AsioSampleType::ASIOSTInt16LSB) => {
process_output_callback::<T, i16, _, _>(
process_output_callback::<i16, i16, _, _>(
&mut data_callback,
&mut interleaved,
silence,
@ -347,7 +347,7 @@ impl Device {
);
}
(SampleFormat::I16, &sys::AsioSampleType::ASIOSTInt16MSB) => {
process_output_callback::<T, i16, _, _>(
process_output_callback::<i16, i16, _, _>(
&mut data_callback,
&mut interleaved,
silence,
@ -361,7 +361,7 @@ impl Device {
// trait for the `to_le` and `to_be` methods, but this does not support floats.
(SampleFormat::F32, &sys::AsioSampleType::ASIOSTFloat32LSB) |
(SampleFormat::F32, &sys::AsioSampleType::ASIOSTFloat32MSB) => {
process_output_callback::<T, f32, _, _>(
process_output_callback::<f32, f32, _, _>(
&mut data_callback,
&mut interleaved,
silence,
@ -375,7 +375,7 @@ impl Device {
// `process_output_callback` function above by removing the unnecessary sample
// conversion function.
(SampleFormat::I16, &sys::AsioSampleType::ASIOSTInt32LSB) => {
process_output_callback::<T, i32, _, _>(
process_output_callback::<i16, i32, _, _>(
&mut data_callback,
&mut interleaved,
silence,
@ -385,7 +385,7 @@ impl Device {
);
}
(SampleFormat::I16, &sys::AsioSampleType::ASIOSTInt32MSB) => {
process_output_callback::<T, i32, _, _>(
process_output_callback::<i16, i32, _, _>(
&mut data_callback,
&mut interleaved,
silence,
@ -398,7 +398,7 @@ impl Device {
// trait for the `to_le` and `to_be` methods, but this does not support floats.
(SampleFormat::F32, &sys::AsioSampleType::ASIOSTFloat64LSB) |
(SampleFormat::F32, &sys::AsioSampleType::ASIOSTFloat64MSB) => {
process_output_callback::<T, f64, _, _>(
process_output_callback::<f32, f64, _, _>(
&mut data_callback,
&mut interleaved,
silence,

View File

@ -5,15 +5,13 @@ use crate::{
ChannelCount,
BackendSpecificError,
BuildStreamError,
Data,
DefaultFormatError,
DeviceNameError,
DevicesError,
Format,
InputData,
OutputData,
PauseStreamError,
PlayStreamError,
Sample,
SampleFormat,
SampleRate,
StreamError,
@ -131,33 +129,29 @@ impl DeviceTrait for Device {
Device::default_output_format(self)
}
fn build_input_stream<T, D, E>(
fn build_input_stream<D, E>(
&self,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
assert_eq!(T::FORMAT, format.data_type);
Device::build_input_stream(self, format, data_callback, error_callback)
}
fn build_output_stream<T, D, E>(
fn build_output_stream<D, E>(
&self,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
assert_eq!(T::FORMAT, format.data_type);
Device::build_output_stream(self, format, data_callback, error_callback)
}
}
@ -500,15 +494,14 @@ fn audio_unit_from_device(device: &Device, input: bool) -> Result<AudioUnit, cor
}
impl Device {
fn build_input_stream<T, D, E>(
fn build_input_stream<D, E>(
&self,
format: &Format,
mut data_callback: D,
_error_callback: E,
) -> Result<Stream, BuildStreamError>
where
T: Sample,
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
// The scope and element for working with a device's input stream.
@ -657,7 +650,8 @@ impl Device {
// Register the callback that is being called by coreaudio whenever it needs data to be
// fed to the audio buffer.
let bytes_per_channel = std::mem::size_of::<T>();
let sample_format = format.data_type;
let bytes_per_channel = sample_format.sample_size();
type Args = render_callback::Args<data::Raw>;
audio_unit.set_input_callback(move |args: Args| unsafe {
let ptr = (*args.data.data).mBuffers.as_ptr() as *const AudioBuffer;
@ -671,10 +665,10 @@ impl Device {
mData: data
} = buffers[0];
let data_len = (data_byte_size as usize / bytes_per_channel) as usize;
let data_slice = slice::from_raw_parts(data as *const T, data_len);
let input_data = InputData { buffer: data_slice };
data_callback(input_data);
let data = data as *mut ();
let len = (data_byte_size as usize / bytes_per_channel) as usize;
let data = Data::from_parts(data, len, sample_format);
data_callback(&data);
Ok(())
})?;
@ -687,15 +681,14 @@ impl Device {
}))
}
fn build_output_stream<T, D, E>(
fn build_output_stream<D, E>(
&self,
format: &Format,
mut data_callback: D,
_error_callback: E,
) -> Result<Stream, BuildStreamError>
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
let mut audio_unit = audio_unit_from_device(self, false)?;
@ -710,7 +703,8 @@ impl Device {
// Register the callback that is being called by coreaudio whenever it needs data to be
// fed to the audio buffer.
let bytes_per_channel = std::mem::size_of::<T>();
let sample_format = format.data_type;
let bytes_per_channel = sample_format.sample_size();
type Args = render_callback::Args<data::Raw>;
audio_unit.set_render_callback(move |args: Args| unsafe {
// If `run()` is currently running, then a callback will be available from this list.
@ -722,10 +716,10 @@ impl Device {
mData: data
} = (*args.data.data).mBuffers[0];
let data_len = (data_byte_size as usize / bytes_per_channel) as usize;
let data_slice = slice::from_raw_parts_mut(data as *mut T, data_len);
let output_data = OutputData { buffer: data_slice };
data_callback(output_data);
let data = data as *mut ();
let len = (data_byte_size as usize / bytes_per_channel) as usize;
let mut data = Data::from_parts(data, len, sample_format);
data_callback(&mut data);
Ok(())
})?;

View File

@ -9,15 +9,13 @@ use stdweb::web::set_timeout;
use crate::{
BuildStreamError,
Data,
DefaultFormatError,
DeviceNameError,
DevicesError,
Format,
InputData,
OutputData,
PauseStreamError,
PlayStreamError,
Sample,
SampleFormat,
StreamError,
SupportedFormat,
@ -160,32 +158,34 @@ impl DeviceTrait for Device {
Device::default_output_format(self)
}
fn build_input_stream<T, D, E>(
fn build_input_stream<D, E>(
&self,
_format: &Format,
_data_callback: D,
_error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
unimplemented!()
}
fn build_output_stream<T, D, E>(
fn build_output_stream<D, E>(
&self,
_format: &Format,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
assert_eq!(T::FORMAT, SampleFormat::F32, "emscripten backend only supports `f32` data");
assert_eq!(
format.data_type,
SampleFormat::F32,
"emscripten backend currently only supports `f32` data",
);
// Create the stream.
let audio_ctxt_ref = js!(return new AudioContext()).into_reference().unwrap();
@ -201,7 +201,7 @@ impl DeviceTrait for Device {
//
// See also: The call to `set_timeout` at the end of the `audio_callback_fn` which creates
// the loop.
set_timeout(|| audio_callback_fn::<T, D, E>(user_data_ptr as *mut c_void), 10);
set_timeout(|| audio_callback_fn::<D, E>(user_data_ptr as *mut c_void), 10);
Ok(stream)
}
@ -223,10 +223,9 @@ impl StreamTrait for Stream {
// The first argument of the callback function (a `void*`) is a casted pointer to `self`
// and to the `callback` parameter that was passed to `run`.
fn audio_callback_fn<T, D, E>(user_data_ptr: *mut c_void)
fn audio_callback_fn<D, E>(user_data_ptr: *mut c_void)
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
unsafe {
@ -236,12 +235,14 @@ where
let audio_ctxt = &stream.audio_ctxt_ref;
// TODO: We should be re-using a buffer.
let mut temporary_buffer: Vec<_> = (0..44100 * 2 / 3).map(|_| T::from(&0.0)).collect();
let mut temporary_buffer = vec![0.0; 44100 * 2 / 3];
{
let buffer = &mut temporary_buffer;
let data = OutputData { buffer };
data_cb(data);
let len = temporary_buffer.len();
let data = temporary_buffer.as_mut_ptr() as *mut ();
let sample_format = SampleFormat::F32;
let mut data = Data::from_parts(data, len, sample_format);
data_cb(&mut data);
}
// TODO: directly use a TypedArray<f32> once this is supported by stdweb
@ -281,7 +282,7 @@ where
// TODO: handle latency better ; right now we just use setInterval with the amount of sound
// data that is in each buffer ; this is obviously bad, and also the schedule is too tight
// and there may be underflows
set_timeout(|| audio_callback_fn::<T, D, E>(user_data_ptr), 330);
set_timeout(|| audio_callback_fn::<D, E>(user_data_ptr), 330);
}
}

View File

@ -1,11 +1,10 @@
use crate::{
BuildStreamError,
Data,
DefaultFormatError,
DevicesError,
DeviceNameError,
Format,
InputData,
OutputData,
PauseStreamError,
PlayStreamError,
StreamError,
@ -71,28 +70,28 @@ impl DeviceTrait for Device {
unimplemented!()
}
fn build_input_stream<T, D, E>(
fn build_input_stream<D, E>(
&self,
_format: &Format,
_data_callback: D,
_error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
unimplemented!()
}
/// Create an output stream.
fn build_output_stream<T, D, E>(
fn build_output_stream<D, E>(
&self,
_format: &Format,
_data_callback: D,
_error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
unimplemented!()

View File

@ -1,12 +1,10 @@
use crate::{
BackendSpecificError,
Data,
DefaultFormatError,
DeviceNameError,
DevicesError,
Format,
InputData,
OutputData,
Sample,
SampleFormat,
SampleRate,
SupportedFormat,
@ -106,30 +104,28 @@ impl DeviceTrait for Device {
Device::default_output_format(self)
}
fn build_input_stream<T, D, E>(
fn build_input_stream<D, E>(
&self,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
let stream_inner = self.build_input_stream_inner(format)?;
Ok(Stream::new_input(stream_inner, data_callback, error_callback))
}
fn build_output_stream<T, D, E>(
fn build_output_stream<D, E>(
&self,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
let stream_inner = self.build_output_stream_inner(format)?;

View File

@ -1,17 +1,14 @@
use crate::{
BackendSpecificError,
InputData,
OutputData,
Data,
PauseStreamError,
PlayStreamError,
Sample,
SampleFormat,
StreamError,
};
use crate::traits::StreamTrait;
use std::mem;
use std::ptr;
use std::slice;
use std::sync::mpsc::{channel, Receiver, Sender};
use std::thread::{self, JoinHandle};
use super::check_result;
@ -85,14 +82,13 @@ pub struct StreamInner {
}
impl Stream {
pub(crate) fn new_input<T, D, E>(
pub(crate) fn new_input<D, E>(
stream_inner: StreamInner,
mut data_callback: D,
mut error_callback: E,
) -> Stream
where
T: Sample,
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
let pending_scheduled_event =
@ -115,14 +111,13 @@ impl Stream {
}
}
pub(crate) fn new_output<T, D, E>(
pub(crate) fn new_output<D, E>(
stream_inner: StreamInner,
mut data_callback: D,
mut error_callback: E,
) -> Stream
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static,
{
let pending_scheduled_event =
@ -285,13 +280,11 @@ fn stream_error_from_hresult(hresult: winnt::HRESULT) -> Result<(), StreamError>
Ok(())
}
fn run_input<T>(
fn run_input(
mut run_ctxt: RunContext,
data_callback: &mut dyn FnMut(InputData<T>),
data_callback: &mut dyn FnMut(&Data),
error_callback: &mut dyn FnMut(StreamError),
) where
T: Sample,
{
) {
loop {
match process_commands_and_await_signal(&mut run_ctxt, error_callback) {
Some(ControlFlow::Break) => break,
@ -309,13 +302,11 @@ fn run_input<T>(
}
}
fn run_output<T>(
fn run_output(
mut run_ctxt: RunContext,
data_callback: &mut dyn FnMut(OutputData<T>),
data_callback: &mut dyn FnMut(&mut Data),
error_callback: &mut dyn FnMut(StreamError),
) where
T: Sample,
{
) {
loop {
match process_commands_and_await_signal(&mut run_ctxt, error_callback) {
Some(ControlFlow::Break) => break,
@ -371,15 +362,12 @@ fn process_commands_and_await_signal(
}
// The loop for processing pending input data.
fn process_input<T>(
fn process_input(
stream: &StreamInner,
capture_client: *mut audioclient::IAudioCaptureClient,
data_callback: &mut dyn FnMut(InputData<T>),
data_callback: &mut dyn FnMut(&Data),
error_callback: &mut dyn FnMut(StreamError),
) -> ControlFlow
where
T: Sample,
{
) -> ControlFlow {
let mut frames_available = 0;
unsafe {
// Get the available data in the shared buffer.
@ -412,15 +400,13 @@ where
debug_assert!(!buffer.is_null());
let buffer_len = frames_available as usize
let data = buffer as *mut ();
let len = frames_available as usize
* stream.bytes_per_frame as usize
/ mem::size_of::<T>();
/ stream.sample_format.sample_size();
let data = Data::from_parts(data, len, stream.sample_format);
data_callback(&data);
// Simplify the capture callback sample format branches.
let buffer_data = buffer as *mut _ as *const T;
let slice = slice::from_raw_parts(buffer_data, buffer_len);
let input_data = InputData { buffer: slice };
data_callback(input_data);
// Release the buffer.
let hresult = (*capture_client).ReleaseBuffer(frames_available);
if let Err(err) = stream_error_from_hresult(hresult) {
@ -432,15 +418,12 @@ where
}
// The loop for writing output data.
fn process_output<T>(
fn process_output(
stream: &StreamInner,
render_client: *mut audioclient::IAudioRenderClient,
data_callback: &mut dyn FnMut(OutputData<T>),
data_callback: &mut dyn FnMut(&mut Data),
error_callback: &mut dyn FnMut(StreamError),
) -> ControlFlow
where
T: Sample,
{
) -> ControlFlow {
// The number of frames available for writing.
let frames_available = match get_available_frames(&stream) {
Ok(0) => return ControlFlow::Continue, // TODO: Can this happen?
@ -462,13 +445,14 @@ where
}
debug_assert!(!buffer.is_null());
let buffer_len =
frames_available as usize * stream.bytes_per_frame as usize / mem::size_of::<T>();
let buffer_data = buffer as *mut T;
let slice = slice::from_raw_parts_mut(buffer_data, buffer_len);
let output_data = OutputData { buffer: slice };
data_callback(output_data);
let data = buffer as *mut ();
let len = frames_available as usize
* stream.bytes_per_frame as usize
/ stream.sample_format.sample_size();
let mut data = Data::from_parts(data, len, stream.sample_format);
data_callback(&mut data);
let hresult = (*render_client).ReleaseBuffer(frames_available as u32, 0);
if let Err(err) = stream_error_from_hresult(hresult) {
error_callback(err);

View File

@ -55,14 +55,14 @@
//! Now that we have everything for the stream, we are ready to create it from our selected device:
//!
//! ```no_run
//! use cpal::OutputData;
//! use cpal::Data;
//! use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
//! # let host = cpal::default_host();
//! # let device = host.default_output_device().unwrap();
//! # let format = device.default_output_format().unwrap();
//! let stream = device.build_output_stream(
//! &format,
//! move |data: OutputData<f32>| {
//! move |data: &mut Data| {
//! // react to stream events and read or write stream data here.
//! },
//! move |err| {
@ -72,9 +72,8 @@
//! ```
//!
//! While the stream is running, the selected audio device will periodically call the data callback
//! that was passed to the function. The callback is passed an instance of either `InputData<T>` or
//! `OutputData<T>` depending on whether the stream is an input stream or output stream
//! respectively. Type `T` represents the desired sample format type. Supported format types
//! that was passed to the function. The callback is passed an instance of either `&Data` or
//! `&mut Data` depending on whether the stream is an input stream or output stream respectively.
//!
//! > **Note**: Creating and running a stream will *not* block the thread. On modern platforms, the
//! > given callback is called by a dedicated, high-priority thread responsible for delivering
@ -85,22 +84,24 @@
//! > please share your issue and use-case with the CPAL team on the github issue tracker for
//! > consideration.*
//!
//! In this example, we simply fill the given output buffer with zeroes.
//! In this example, we simply fill the given output buffer with silence.
//!
//! ```no_run
//! use cpal::{OutputData, Sample, SampleFormat};
//! use cpal::{Data, Sample, SampleFormat};
//! use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
//! # let host = cpal::default_host();
//! # let device = host.default_output_device().unwrap();
//! # let format = device.default_output_format().unwrap();
//! let err_fn = move |err| eprintln!("an error occurred on the output audio stream: {}", err);
//! let stream = match format.data_type {
//! SampleFormat::F32 => device.build_output_stream(&format, write_silence::<f32>, err_fn),
//! SampleFormat::I16 => device.build_output_stream(&format, write_silence::<i16>, err_fn),
//! SampleFormat::U16 => device.build_output_stream(&format, write_silence::<u16>, err_fn),
//! let err_fn = |err| eprintln!("an error occurred on the output audio stream: {}", err);
//! let data_fn = move |data: &mut Data| match data.sample_format() {
//! SampleFormat::F32 => write_silence::<f32>(data),
//! SampleFormat::I16 => write_silence::<i16>(data),
//! SampleFormat::U16 => write_silence::<u16>(data),
//! };
//! let stream = device.build_output_stream(&format, data_fn, err_fn).unwrap();
//!
//! fn write_silence<T: Sample>(mut data: OutputData<T>) {
//! fn write_silence<T: Sample>(data: &mut Data) {
//! let data = data.as_slice_mut::<T>().unwrap();
//! for sample in data.iter_mut() {
//! *sample = Sample::from(&0.0);
//! }
@ -115,7 +116,7 @@
//! # let host = cpal::default_host();
//! # let device = host.default_output_device().unwrap();
//! # let format = device.default_output_format().unwrap();
//! # let data_fn = move |_data: cpal::OutputData<f32>| {};
//! # let data_fn = move |_data: &mut cpal::Data| {};
//! # let err_fn = move |_err| {};
//! # let stream = device.build_output_stream(&format, data_fn, err_fn).unwrap();
//! stream.play().unwrap();
@ -129,7 +130,7 @@
//! # let host = cpal::default_host();
//! # let device = host.default_output_device().unwrap();
//! # let format = device.default_output_format().unwrap();
//! # let data_fn = move |_data: cpal::OutputData<f32>| {};
//! # let data_fn = move |_data: &mut cpal::Data| {};
//! # let err_fn = move |_err| {};
//! # let stream = device.build_output_stream(&format, data_fn, err_fn).unwrap();
//! stream.pause().unwrap();
@ -152,7 +153,6 @@ pub use platform::{
HostId, Stream, SupportedInputFormats, SupportedOutputFormats,
};
pub use samples_formats::{Sample, SampleFormat};
use std::ops::{Deref, DerefMut};
mod error;
mod host;
@ -193,34 +193,106 @@ pub struct SupportedFormat {
pub data_type: SampleFormat,
}
/// Represents a buffer containing audio data that may be read.
/// Represents a buffer of audio data, delivered via a user's stream data callback function.
///
/// This struct implements the `Deref` trait targeting `[T]`. Therefore this buffer can be read the
/// same way as reading from a `Vec` or any other kind of Rust array.
// TODO: explain audio stuff in general
// TODO: Consider making this an `enum` with `Interleaved` and `NonInterleaved` variants.
/// Input stream callbacks receive `&Data`, while output stream callbacks expect `&mut Data`.
#[derive(Debug)]
pub struct InputData<'a, T: 'a>
where
T: Sample,
{
buffer: &'a [T],
pub struct Data {
data: *mut (),
len: usize,
sample_format: SampleFormat,
}
/// Represents a buffer that must be filled with audio data. The buffer in unfilled state may
/// contain garbage values.
///
/// This struct implements the `Deref` and `DerefMut` traits to `[T]`. Therefore writing to this
/// buffer is done in the same way as writing to a `Vec` or any other kind of Rust array.
// TODO: explain audio stuff in general
// TODO: Consider making this an `enum` with `Interleaved` and `NonInterleaved` variants.
#[must_use]
#[derive(Debug)]
pub struct OutputData<'a, T: 'a>
where
T: Sample,
{
buffer: &'a mut [T],
impl Data {
// Internal constructor for host implementations to use.
//
// The following requirements must be met in order for the safety of `Data`'s public API.
//
// - The `data` pointer must point to the first sample in the slice containing all samples.
// - The `len` must describe the length of the buffer as a number of samples in the expected
// format specified via the `sample_format` argument.
// - The `sample_format` must correctly represent the underlying sample data delivered/expected
// by the stream.
pub(crate) unsafe fn from_parts(
data: *mut (),
len: usize,
sample_format: SampleFormat,
) -> Self {
Data { data, len, sample_format }
}
/// The sample format of the internal audio data.
pub fn sample_format(&self) -> SampleFormat {
self.sample_format
}
/// The full length of the buffer in samples.
///
/// The returned length is the same length as the slice of type `T` that would be returned via
/// `as_slice` given a sample type that matches the inner sample format.
pub fn len(&self) -> usize {
self.len
}
/// The raw slice of memory representing the underlying audio data as a slice of bytes.
///
/// It is up to the user to interpret the slice of memory based on `Data::sample_format`.
pub fn bytes(&self) -> &[u8] {
let len = self.len * self.sample_format.sample_size();
// The safety of this block relies on correct construction of the `Data` instance. See
// the unsafe `from_parts` constructor for these requirements.
unsafe {
std::slice::from_raw_parts(self.data as *const u8, len)
}
}
/// The raw slice of memory representing the underlying audio data as a slice of bytes.
///
/// It is up to the user to interpret the slice of memory based on `Data::sample_format`.
pub fn bytes_mut(&mut self) -> &mut [u8] {
let len = self.len * self.sample_format.sample_size();
// The safety of this block relies on correct construction of the `Data` instance. See
// the unsafe `from_parts` constructor for these requirements.
unsafe {
std::slice::from_raw_parts_mut(self.data as *mut u8, len)
}
}
/// Access the data as a slice of sample type `T`.
///
/// Returns `None` if the sample type does not match the expected sample format.
pub fn as_slice<T>(&self) -> Option<&[T]>
where
T: Sample,
{
if T::FORMAT == self.sample_format {
// The safety of this block relies on correct construction of the `Data` instance. See
// the unsafe `from_parts` constructor for these requirements.
unsafe {
Some(std::slice::from_raw_parts(self.data as *const T, self.len))
}
} else {
None
}
}
/// Access the data as a slice of sample type `T`.
///
/// Returns `None` if the sample type does not match the expected sample format.
pub fn as_slice_mut<T>(&mut self) -> Option<&mut [T]>
where
T: Sample,
{
if T::FORMAT == self.sample_format {
// The safety of this block relies on correct construction of the `Data` instance. See
// the unsafe `from_parts` constructor for these requirements.
unsafe {
Some(std::slice::from_raw_parts_mut(self.data as *mut T, self.len))
}
} else {
None
}
}
}
impl SupportedFormat {
@ -306,40 +378,6 @@ impl SupportedFormat {
}
}
impl<'a, T> Deref for InputData<'a, T>
where
T: Sample,
{
type Target = [T];
#[inline]
fn deref(&self) -> &[T] {
self.buffer
}
}
impl<'a, T> Deref for OutputData<'a, T>
where
T: Sample,
{
type Target = [T];
#[inline]
fn deref(&self) -> &[T] {
self.buffer
}
}
impl<'a, T> DerefMut for OutputData<'a, T>
where
T: Sample,
{
#[inline]
fn deref_mut(&mut self) -> &mut [T] {
self.buffer
}
}
impl From<Format> for SupportedFormat {
#[inline]
fn from(format: Format) -> SupportedFormat {

View File

@ -255,15 +255,14 @@ macro_rules! impl_platform_host {
}
}
fn build_input_stream<T, D, E>(
fn build_input_stream<D, E>(
&self,
format: &crate::Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, crate::BuildStreamError>
where
T: crate::Sample,
D: FnMut(crate::InputData<T>) + Send + 'static,
D: FnMut(&crate::Data) + Send + 'static,
E: FnMut(crate::StreamError) + Send + 'static,
{
match self.0 {
@ -275,15 +274,14 @@ macro_rules! impl_platform_host {
}
}
fn build_output_stream<T, D, E>(
fn build_output_stream<D, E>(
&self,
format: &crate::Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, crate::BuildStreamError>
where
T: crate::Sample,
D: FnMut(crate::OutputData<T>) + Send + 'static,
D: FnMut(&mut crate::Data) + Send + 'static,
E: FnMut(crate::StreamError) + Send + 'static,
{
match self.0 {

View File

@ -2,17 +2,15 @@
use {
BuildStreamError,
Data,
DefaultFormatError,
DeviceNameError,
DevicesError,
Format,
InputData,
InputDevices,
OutputData,
OutputDevices,
PauseStreamError,
PlayStreamError,
Sample,
StreamError,
SupportedFormat,
SupportedFormatsError,
@ -120,27 +118,25 @@ pub trait DeviceTrait {
fn default_output_format(&self) -> Result<Format, DefaultFormatError>;
/// Create an input stream.
fn build_input_stream<T, D, E>(
fn build_input_stream<D, E>(
&self,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(InputData<T>) + Send + 'static,
D: FnMut(&Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static;
/// Create an output stream.
fn build_output_stream<T, D, E>(
fn build_output_stream<D, E>(
&self,
format: &Format,
data_callback: D,
error_callback: E,
) -> Result<Self::Stream, BuildStreamError>
where
T: Sample,
D: FnMut(OutputData<T>) + Send + 'static,
D: FnMut(&mut Data) + Send + 'static,
E: FnMut(StreamError) + Send + 'static;
}