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Correctly enumerate audio devices (core + wasapi)

This commit is contained in:
Pierre Krieger 2015-09-01 11:23:41 +02:00
parent 659aeba42d
commit 47f966bf75
7 changed files with 457 additions and 241 deletions
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1
Cargo.toml
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@ -11,6 +11,7 @@ keywords = ["audio", "sound"]
[dependencies]
libc = "*"
lazy_static = "0.1"
[target.i686-pc-windows-gnu.dependencies]
winapi = "0.2.1"

2
examples/beep.rs
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@ -1,7 +1,7 @@
extern crate cpal;
fn main() {
let mut channel = cpal::Voice::new();
let mut channel = cpal::Voice::new(&cpal::get_default_endpoint().unwrap()).unwrap();
// Produce a sinusoid of maximum amplitude.
let mut data_source = (0u64..).map(|t| t as f32 * 0.03)

47
src/lib.rs
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@ -28,8 +28,12 @@ reaches the end of the data, it will stop playing. You must continuously fill th
calling `append_data` repeatedly if you don't want the audio to stop playing.
*/
#[macro_use]
extern crate lazy_static;
pub use samples_formats::{SampleFormat, Sample};
use std::error::Error;
use std::ops::{Deref, DerefMut};
mod samples_formats;
@ -57,6 +61,43 @@ pub type ChannelsCount = u16;
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub struct SamplesRate(pub u32);
/// Describes a format.
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub struct Format {
pub channels: ChannelsCount,
pub samples_rate: SamplesRate,
pub data_type: SampleFormat,
}
/// An iterator for the list of formats that are supported by the backend.
pub struct EndpointsIterator(cpal_impl::EndpointsIterator);
impl Iterator for EndpointsIterator {
type Item = Endpoint;
fn next(&mut self) -> Option<Endpoint> {
self.0.next().map(Endpoint)
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.0.size_hint()
}
}
/// Return an iterator to the list of formats that are supported by the system.
pub fn get_endpoints_list() -> EndpointsIterator {
EndpointsIterator(Default::default())
}
/// Return the default endpoint, or `None` if no device is available.
pub fn get_default_endpoint() -> Option<Endpoint> {
cpal_impl::get_default_endpoint().map(Endpoint)
}
/// An opaque type that identifies an end point.
#[derive(Clone, PartialEq, Eq)]
pub struct Endpoint(cpal_impl::Endpoint);
/// Represents a buffer that must be filled with audio data.
///
/// You should destroy this object as soon as possible. Data is only committed when it
@ -95,9 +136,9 @@ pub struct Voice(cpal_impl::Voice);
impl Voice {
/// Builds a new channel.
pub fn new() -> Voice {
let channel = cpal_impl::Voice::new();
Voice(channel)
pub fn new(endpoint: &Endpoint) -> Result<Voice, Box<Error>> {
let channel = try!(cpal_impl::Voice::new(&endpoint.0));
Ok(Voice(channel))
}
/// Returns the number of channels.

32
src/wasapi/com.rs Normal file
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@ -0,0 +1,32 @@
//! Handles COM initialization and cleanup.
use std::ptr;
use super::winapi;
use super::ole32;
use super::check_result;
thread_local!(static COM_INITIALIZED: ComInitialized = {
unsafe {
// this call can fail if another library initialized COM in single-threaded mode
// handling this situation properly would make the API more annoying, so we just don't care
check_result(ole32::CoInitializeEx(ptr::null_mut(), winapi::COINIT_MULTITHREADED)).unwrap();
ComInitialized(ptr::null_mut())
}
});
/// RAII object that guards the fact that COM is initialized.
///
// We store a raw pointer because it's the only way at the moment to remove `Send`/`Sync` from the
// object.
struct ComInitialized(*mut ());
impl Drop for ComInitialized {
fn drop(&mut self) {
unsafe { ole32::CoUninitialize() };
}
}
/// Ensures that COM is initialized in this thread.
pub fn com_initialized() {
COM_INITIALIZED.with(|_| {});
}

126
src/wasapi/enumerate.rs Normal file
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@ -0,0 +1,126 @@
use super::winapi;
use super::ole32;
use super::com;
use super::Endpoint;
use super::check_result;
use std::mem;
use std::ptr;
lazy_static! {
static ref ENUMERATOR: Enumerator = {
// COM initialization is thread local, but we only need to have COM initialized in the
// thread we create the objects in
com::com_initialized();
// building the devices enumerator object
unsafe {
let mut enumerator: *mut winapi::IMMDeviceEnumerator = mem::uninitialized();
let hresult = ole32::CoCreateInstance(&winapi::CLSID_MMDeviceEnumerator,
ptr::null_mut(), winapi::CLSCTX_ALL,
&winapi::IID_IMMDeviceEnumerator,
&mut enumerator
as *mut *mut winapi::IMMDeviceEnumerator
as *mut _);
check_result(hresult).unwrap();
Enumerator(enumerator)
}
};
}
/// RAII object around `winapi::IMMDeviceEnumerator`.
struct Enumerator(*mut winapi::IMMDeviceEnumerator);
unsafe impl Send for Enumerator {}
unsafe impl Sync for Enumerator {}
impl Drop for Enumerator {
fn drop(&mut self) {
unsafe {
(*self.0).Release();
}
}
}
/// WASAPI implementation for `EndpointsIterator`.
pub struct EndpointsIterator {
collection: *mut winapi::IMMDeviceCollection,
total_count: u32,
next_item: u32,
}
unsafe impl Send for EndpointsIterator {}
unsafe impl Sync for EndpointsIterator {}
impl Drop for EndpointsIterator {
fn drop(&mut self) {
unsafe {
(*self.collection).Release();
}
}
}
impl Default for EndpointsIterator {
fn default() -> EndpointsIterator {
unsafe {
let mut collection: *mut winapi::IMMDeviceCollection = mem::uninitialized();
// can fail because of wrong parameters (should never happen) or out of memory
check_result((*ENUMERATOR.0).EnumAudioEndpoints(winapi::EDataFlow::eRender,
winapi::DEVICE_STATE_ACTIVE,
&mut collection))
.unwrap();
let mut count = mem::uninitialized();
// can fail if the parameter is null, which should never happen
check_result((*collection).GetCount(&mut count)).unwrap();
EndpointsIterator {
collection: collection,
total_count: count,
next_item: 0,
}
}
}
}
impl Iterator for EndpointsIterator {
type Item = Endpoint;
fn next(&mut self) -> Option<Endpoint> {
if self.next_item >= self.total_count {
return None;
}
unsafe {
let mut device = mem::uninitialized();
// can fail if out of range, which we just checked above
check_result((*self.collection).Item(self.next_item, &mut device)).unwrap();
self.next_item += 1;
Some(Endpoint(device))
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let num = self.total_count - self.next_item;
let num = num as usize;
(num, Some(num))
}
}
pub fn get_default_endpoint() -> Option<Endpoint> {
unsafe {
let mut device = mem::uninitialized();
let hres = (*ENUMERATOR.0).GetDefaultAudioEndpoint(winapi::EDataFlow::eRender,
winapi::ERole::eConsole, &mut device);
if let Err(_err) = check_result(hres) {
return None; // TODO: check specifically for `E_NOTFOUND`, and panic otherwise
}
Some(Endpoint(device))
}
}

259
src/wasapi/mod.rs
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@ -2,255 +2,40 @@ extern crate libc;
extern crate winapi;
extern crate ole32;
use std::{cmp, slice, mem, ptr};
use std::marker::PhantomData;
use std::io::Error as IoError;
// TODO: determine if should be NoSend or not
pub struct Voice {
audio_client: *mut winapi::IAudioClient,
render_client: *mut winapi::IAudioRenderClient,
max_frames_in_buffer: winapi::UINT32,
num_channels: winapi::WORD,
bytes_per_frame: winapi::WORD,
samples_per_second: winapi::DWORD,
bits_per_sample: winapi::WORD,
playing: bool,
}
pub use self::enumerate::{EndpointsIterator, get_default_endpoint};
pub use self::voice::{Voice, Buffer};
pub struct Buffer<'a, T: 'a> {
render_client: *mut winapi::IAudioRenderClient,
buffer_data: *mut T,
buffer_len: usize,
frames: winapi::UINT32,
marker: PhantomData<&'a mut T>,
}
mod com;
mod enumerate;
mod voice;
impl Voice {
pub fn new() -> Voice {
init().unwrap()
}
/// An opaque type that identifies an end point.
#[derive(PartialEq, Eq)]
#[allow(raw_pointer_derive)]
pub struct Endpoint(*mut winapi::IMMDevice);
pub fn get_channels(&self) -> ::ChannelsCount {
self.num_channels as ::ChannelsCount
}
unsafe impl Send for Endpoint {}
unsafe impl Sync for Endpoint {}
pub fn get_samples_rate(&self) -> ::SamplesRate {
::SamplesRate(self.samples_per_second as u32)
}
pub fn get_samples_format(&self) -> ::SampleFormat {
match self.bits_per_sample {
16 => ::SampleFormat::I16,
_ => panic!("{}-bit format not yet supported", self.bits_per_sample),
impl Clone for Endpoint {
fn clone(&self) -> Endpoint {
unsafe { (*self.0).AddRef(); }
Endpoint(self.0)
}
}
pub fn append_data<'a, T>(&'a mut self, max_elements: usize) -> Buffer<'a, T> {
unsafe {
loop {
//
let frames_available = {
let mut padding = mem::uninitialized();
let hresult = (*self.audio_client).GetCurrentPadding(&mut padding);
check_result(hresult).unwrap();
self.max_frames_in_buffer - padding
};
if frames_available == 0 {
// TODO:
::std::thread::sleep_ms(1);
continue;
}
let frames_available = cmp::min(frames_available,
max_elements as u32 * mem::size_of::<T>() as u32 /
self.bytes_per_frame as u32);
assert!(frames_available != 0);
// loading buffer
let (buffer_data, buffer_len) = {
let mut buffer: *mut winapi::BYTE = mem::uninitialized();
let hresult = (*self.render_client).GetBuffer(frames_available,
&mut buffer as *mut *mut libc::c_uchar);
check_result(hresult).unwrap();
assert!(!buffer.is_null());
(buffer as *mut T,
frames_available as usize * self.bytes_per_frame as usize
/ mem::size_of::<T>())
};
let buffer = Buffer {
render_client: self.render_client,
buffer_data: buffer_data,
buffer_len: buffer_len,
frames: frames_available,
marker: PhantomData,
};
return buffer;
}
}
}
pub fn play(&mut self) {
if !self.playing {
unsafe {
let hresult = (*self.audio_client).Start();
check_result(hresult).unwrap();
}
}
self.playing = true;
}
pub fn pause(&mut self) {
if self.playing {
unsafe {
let hresult = (*self.audio_client).Stop();
check_result(hresult).unwrap();
}
}
self.playing = false;
}
}
unsafe impl Send for Voice {}
unsafe impl Sync for Voice {}
impl Drop for Voice {
impl Drop for Endpoint {
fn drop(&mut self) {
unsafe {
(*self.render_client).Release();
(*self.audio_client).Release();
}
}
}
impl<'a, T> Buffer<'a, T> {
pub fn get_buffer<'b>(&'b mut self) -> &'b mut [T] {
unsafe {
slice::from_raw_parts_mut(self.buffer_data, self.buffer_len)
unsafe { (*self.0).Release(); }
}
}
pub fn finish(self) {
// releasing buffer
unsafe {
let hresult = (*self.render_client).ReleaseBuffer(self.frames as u32, 0);
check_result(hresult).unwrap();
};
}
}
fn init() -> Result<Voice, String> {
// FIXME: release everything
unsafe {
try!(check_result(ole32::CoInitializeEx(ptr::null_mut(), 0)));
// building the devices enumerator object
let enumerator = {
let mut enumerator: *mut winapi::IMMDeviceEnumerator = mem::uninitialized();
let hresult = ole32::CoCreateInstance(&winapi::CLSID_MMDeviceEnumerator,
ptr::null_mut(), winapi::CLSCTX_ALL,
&winapi::IID_IMMDeviceEnumerator,
mem::transmute(&mut enumerator));
try!(check_result(hresult));
&mut *enumerator
};
// getting the default end-point
let device = {
let mut device: *mut winapi::IMMDevice = mem::uninitialized();
let hresult = enumerator.GetDefaultAudioEndpoint(winapi::EDataFlow::eRender, winapi::ERole::eConsole,
mem::transmute(&mut device));
try!(check_result(hresult));
&mut *device
};
// activating in order to get a `IAudioClient`
let audio_client: &mut winapi::IAudioClient = {
let mut audio_client: *mut winapi::IAudioClient = mem::uninitialized();
let hresult = device.Activate(&winapi::IID_IAudioClient, winapi::CLSCTX_ALL,
ptr::null_mut(), mem::transmute(&mut audio_client));
try!(check_result(hresult));
&mut *audio_client
};
// computing the format and initializing the device
let format = {
let format_attempt = winapi::WAVEFORMATEX {
wFormatTag: 1, // WAVE_FORMAT_PCM ; TODO: replace by constant
nChannels: 2,
nSamplesPerSec: 44100,
nAvgBytesPerSec: 2 * 44100 * 2,
nBlockAlign: (2 * 16) / 8,
wBitsPerSample: 16,
cbSize: 0,
};
let mut format_ptr: *mut winapi::WAVEFORMATEX = mem::uninitialized();
let hresult = audio_client.IsFormatSupported(winapi::AUDCLNT_SHAREMODE::AUDCLNT_SHAREMODE_SHARED,
&format_attempt, &mut format_ptr);
try!(check_result(hresult));
let format = if format_ptr.is_null() {
&format_attempt
} else {
&*format_ptr
};
let format_copy = ptr::read(format);
let hresult = audio_client.Initialize(winapi::AUDCLNT_SHAREMODE::AUDCLNT_SHAREMODE_SHARED,
0, 10000000, 0, format, ptr::null());
if !format_ptr.is_null() {
ole32::CoTaskMemFree(format_ptr as *mut _);
}
try!(check_result(hresult));
format_copy
};
//
let max_frames_in_buffer = {
let mut max_frames_in_buffer = mem::uninitialized();
let hresult = audio_client.GetBufferSize(&mut max_frames_in_buffer);
try!(check_result(hresult));
max_frames_in_buffer
};
//
let render_client = {
let mut render_client: *mut winapi::IAudioRenderClient = mem::uninitialized();
let hresult = audio_client.GetService(&winapi::IID_IAudioRenderClient,
mem::transmute(&mut render_client));
try!(check_result(hresult));
&mut *render_client
};
Ok(Voice {
audio_client: audio_client,
render_client: render_client,
max_frames_in_buffer: max_frames_in_buffer,
num_channels: format.nChannels,
bytes_per_frame: format.nBlockAlign,
samples_per_second: format.nSamplesPerSec,
bits_per_sample: format.wBitsPerSample,
playing: false,
})
}
}
fn check_result(result: winapi::HRESULT) -> Result<(), String> {
fn check_result(result: winapi::HRESULT) -> Result<(), IoError> {
if result < 0 {
return Err(format!("Error in winapi call")); // TODO:
}
Err(IoError::from_raw_os_error(result))
} else {
Ok(())
}
}

231
src/wasapi/voice.rs Normal file
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@ -0,0 +1,231 @@
use super::com;
use super::ole32;
use super::winapi;
use super::Endpoint;
use super::check_result;
use std::io::Error as IoError;
use std::cmp;
use std::slice;
use std::mem;
use std::ptr;
use std::marker::PhantomData;
pub struct Voice {
audio_client: *mut winapi::IAudioClient,
render_client: *mut winapi::IAudioRenderClient,
max_frames_in_buffer: winapi::UINT32,
num_channels: winapi::WORD,
bytes_per_frame: winapi::WORD,
samples_per_second: winapi::DWORD,
bits_per_sample: winapi::WORD,
playing: bool,
}
unsafe impl Send for Voice {}
unsafe impl Sync for Voice {}
impl Voice {
pub fn new(end_point: &Endpoint) -> Result<Voice, IoError> {
// FIXME: release everything
unsafe {
// making sure that COM is initialized
// it's not actually sure that this is required, but when in doubt do it
com::com_initialized();
// activating the end point in order to get a `IAudioClient`
let audio_client: *mut winapi::IAudioClient = {
let mut audio_client = mem::uninitialized();
let hresult = (*end_point.0).Activate(&winapi::IID_IAudioClient, winapi::CLSCTX_ALL,
ptr::null_mut(), &mut audio_client);
// can fail if the device has been disconnected since we enumerated it, or if
// the device doesn't support playback for some reason
try!(check_result(hresult));
audio_client as *mut _
};
// computing the format and initializing the device
let format = {
let format_attempt = winapi::WAVEFORMATEX {
wFormatTag: 1, // WAVE_FORMAT_PCM ; TODO: replace by constant
nChannels: 2,
nSamplesPerSec: 44100,
nAvgBytesPerSec: 2 * 44100 * 2,
nBlockAlign: (2 * 16) / 8,
wBitsPerSample: 16,
cbSize: 0,
};
let mut format_ptr: *mut winapi::WAVEFORMATEX = mem::uninitialized();
let hresult = (*audio_client).IsFormatSupported(winapi::AUDCLNT_SHAREMODE::AUDCLNT_SHAREMODE_SHARED,
&format_attempt, &mut format_ptr);
try!(check_result(hresult));
let format = if format_ptr.is_null() {
&format_attempt
} else {
&*format_ptr
};
let format_copy = ptr::read(format);
let hresult = (*audio_client).Initialize(winapi::AUDCLNT_SHAREMODE::AUDCLNT_SHAREMODE_SHARED,
0, 10000000, 0, format, ptr::null());
if !format_ptr.is_null() {
ole32::CoTaskMemFree(format_ptr as *mut _);
}
try!(check_result(hresult));
format_copy
};
//
let max_frames_in_buffer = {
let mut max_frames_in_buffer = mem::uninitialized();
let hresult = (*audio_client).GetBufferSize(&mut max_frames_in_buffer);
try!(check_result(hresult));
max_frames_in_buffer
};
//
let render_client = {
let mut render_client: *mut winapi::IAudioRenderClient = mem::uninitialized();
let hresult = (*audio_client).GetService(&winapi::IID_IAudioRenderClient,
mem::transmute(&mut render_client));
try!(check_result(hresult));
&mut *render_client
};
Ok(Voice {
audio_client: audio_client,
render_client: render_client,
max_frames_in_buffer: max_frames_in_buffer,
num_channels: format.nChannels,
bytes_per_frame: format.nBlockAlign,
samples_per_second: format.nSamplesPerSec,
bits_per_sample: format.wBitsPerSample,
playing: false,
})
}
}
pub fn get_channels(&self) -> ::ChannelsCount {
self.num_channels as ::ChannelsCount
}
pub fn get_samples_rate(&self) -> ::SamplesRate {
::SamplesRate(self.samples_per_second as u32)
}
pub fn get_samples_format(&self) -> ::SampleFormat {
match self.bits_per_sample {
16 => ::SampleFormat::I16,
_ => panic!("{}-bit format not yet supported", self.bits_per_sample),
}
}
pub fn append_data<'a, T>(&'a mut self, max_elements: usize) -> Buffer<'a, T> {
unsafe {
loop {
//
let frames_available = {
let mut padding = mem::uninitialized();
let hresult = (*self.audio_client).GetCurrentPadding(&mut padding);
check_result(hresult).unwrap();
self.max_frames_in_buffer - padding
};
if frames_available == 0 {
// TODO:
::std::thread::sleep_ms(1);
continue;
}
let frames_available = cmp::min(frames_available,
max_elements as u32 * mem::size_of::<T>() as u32 /
self.bytes_per_frame as u32);
assert!(frames_available != 0);
// loading buffer
let (buffer_data, buffer_len) = {
let mut buffer: *mut winapi::BYTE = mem::uninitialized();
let hresult = (*self.render_client).GetBuffer(frames_available,
&mut buffer as *mut *mut _);
check_result(hresult).unwrap();
assert!(!buffer.is_null());
(buffer as *mut T,
frames_available as usize * self.bytes_per_frame as usize
/ mem::size_of::<T>())
};
let buffer = Buffer {
render_client: self.render_client,
buffer_data: buffer_data,
buffer_len: buffer_len,
frames: frames_available,
marker: PhantomData,
};
return buffer;
}
}
}
pub fn play(&mut self) {
if !self.playing {
unsafe {
let hresult = (*self.audio_client).Start();
check_result(hresult).unwrap();
}
}
self.playing = true;
}
pub fn pause(&mut self) {
if self.playing {
unsafe {
let hresult = (*self.audio_client).Stop();
check_result(hresult).unwrap();
}
}
self.playing = false;
}
}
impl Drop for Voice {
fn drop(&mut self) {
unsafe {
(*self.render_client).Release();
(*self.audio_client).Release();
}
}
}
pub struct Buffer<'a, T: 'a> {
render_client: *mut winapi::IAudioRenderClient,
buffer_data: *mut T,
buffer_len: usize,
frames: winapi::UINT32,
marker: PhantomData<&'a mut T>,
}
impl<'a, T> Buffer<'a, T> {
pub fn get_buffer<'b>(&'b mut self) -> &'b mut [T] {
unsafe {
slice::from_raw_parts_mut(self.buffer_data, self.buffer_len)
}
}
pub fn finish(self) {
// releasing buffer
unsafe {
let hresult = (*self.render_client).ReleaseBuffer(self.frames as u32, 0);
check_result(hresult).unwrap();
};
}
}