1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
extern crate portaudio;
use portaudio as pa;
use std::sync::mpsc::*;
const SAMPLE_RATE: f64 = 44100.0;
const FRAMES: usize = 512;
pub fn init() -> Result<pa::PortAudio, pa::Error> {
pa::PortAudio::new()
}
pub fn get_device_list(pa: &pa::PortAudio) -> Result<Vec<(u32, String)>, pa::Error> {
// This pa.devices gives a Result of devices, each of which is
// also a Result. So a Result<Collection<Result<Device>>>. We
// mould it into devices: a Vec<(index, DeviceInfo)>.
let devices = try!(try!(pa.devices()).map(|device| {
device.map(|(pa::DeviceIndex(idx), info)| (idx, info))
}).collect::<Result<Vec<_>, _>>());
let list = devices.iter().filter(|&&(_, ref info)| info.max_input_channels > 0)
.map(|&(idx, ref info)| (idx, info.name.to_string()))
.collect();
Ok(list)
}
//#[test]
fn get_device_list_returns_devices() {
let pa = init().expect("Could not init portaudio");
let devices = get_device_list(&pa).expect("Getting devices had an error");
// all machines should have at least one input stream, even if
// that's just a virtual stream with a name like "default".
assert!(devices.len() > 0);
}
pub fn start_listening(pa: &pa::PortAudio, device_index: u32,
sender: Sender<Vec<f64>>) -> Result<pa::Stream<pa::NonBlocking, pa::Input<f32>>, pa::Error> {
let device_info = try!(pa.device_info(pa::DeviceIndex(device_index)));
let latency = device_info.default_low_input_latency;
// Construct the input stream parameters.
let input_params = pa::StreamParameters::<f32>::new(pa::DeviceIndex(device_index), 1, true, latency);
// Check that the stream format is supported.
try!(pa.is_input_format_supported(input_params, SAMPLE_RATE));
// Construct the settings with which we'll open our stream.
let stream_settings = pa::InputStreamSettings::new(input_params, SAMPLE_RATE, FRAMES as u32);
// This callback A callback to pass to the non-blocking stream.
let callback = move |pa::InputStreamCallbackArgs { buffer, .. }| {
sender.send(buffer.iter().map(|&s| s as f64).collect()).ok();
pa::Continue
};
let mut stream = try!(pa.open_non_blocking_stream(stream_settings, callback));
try!(stream.start());
Ok(stream)
}
//#[test]
fn start_listening_returns_successfully() {
let pa = init().expect("Could not init portaudio");
let devices = get_device_list(&pa).expect("Getting devices had an error");
let device = devices.first().expect("Should have at least one device");
let (sender, _) = channel();
start_listening(&pa, device.0, sender).expect("Error starting listening to first channel");
}
|
