extern crate libc;
extern crate winapi;
extern crate ole32;
use std::{slice, mem, 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,
}
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 Voice {
pub fn new() -> Voice {
init().unwrap()
}
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::U16,
_ => unimplemented!(),
}
}
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 {
::std::thread::sleep_ms(1);
continue;
}
let frames_available = ::std::cmp::min(frames_available,
max_elements as u32 * mem::size_of::<T>() as u32 /
self.bytes_per_frame as u32);
assert!(frames_available != 0);
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 {
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)
}
}
pub fn finish(self) {
unsafe {
let hresult = (*self.render_client).ReleaseBuffer(self.frames as u32, 0);
check_result(hresult).unwrap();
};
}
}
fn init() -> Result<Voice, String> {
unsafe {
try!(check_result(ole32::CoInitializeEx(::std::ptr::null_mut(), 0)));
let enumerator = {
let mut enumerator: *mut winapi::IMMDeviceEnumerator = ::std::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
};
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
};
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
};
let format = {
let format_attempt = winapi::WAVEFORMATEX {
wFormatTag: 1, 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 libc::c_void);
}
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> {
if result < 0 {
return Err(format!("Error in winapi call")); }
Ok(())
}