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Uses ringbuffer in feedback example (#331) 

Uses ringbuffer in feedback example
This commit is contained in:
Tatsuyuki Ishi 2019-10-01 11:09:49 +09:00 committed by GitHub
parent fabf432a1a 1676bf20b6
commit 4863a00225
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 13 additions and 7 deletions
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1
Cargo.toml
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@ -18,6 +18,7 @@ num-traits = "0.2.6"
[dev-dependencies] [dev-dependencies]
hound = "3.4" hound = "3.4"
ringbuf = "0.1.6"
[target.'cfg(target_os = "windows")'.dependencies] [target.'cfg(target_os = "windows")'.dependencies]
winapi = { version = "0.3", features = ["audiosessiontypes", "audioclient", "coml2api", "combaseapi", "debug", "devpkey", "handleapi", "ksmedia", "mmdeviceapi", "objbase", "std", "synchapi", "winuser"] } winapi = { version = "0.3", features = ["audiosessiontypes", "audioclient", "coml2api", "combaseapi", "debug", "devpkey", "handleapi", "ksmedia", "mmdeviceapi", "objbase", "std", "synchapi", "winuser"] }

19
examples/feedback.rs
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@ -8,8 +8,10 @@
extern crate cpal; extern crate cpal;
extern crate failure; extern crate failure;
extern crate ringbuf;
use cpal::traits::{DeviceTrait, EventLoopTrait, HostTrait}; use cpal::traits::{DeviceTrait, EventLoopTrait, HostTrait};
use ringbuf::RingBuffer;
const LATENCY_MS: f32 = 150.0; const LATENCY_MS: f32 = 150.0;
@ -37,12 +39,15 @@ fn main() -> Result<(), failure::Error> {
let latency_frames = (LATENCY_MS / 1_000.0) * format.sample_rate.0 as f32; let latency_frames = (LATENCY_MS / 1_000.0) * format.sample_rate.0 as f32;
let latency_samples = latency_frames as usize * format.channels as usize; let latency_samples = latency_frames as usize * format.channels as usize;
// The channel to share samples. // The buffer to share samples
let (tx, rx) = std::sync::mpsc::sync_channel(latency_samples * 2); let ring = RingBuffer::new(latency_samples * 2);
let (mut producer, mut consumer) = ring.split();
// Fill the samples with 0.0 equal to the length of the delay. // Fill the samples with 0.0 equal to the length of the delay.
for _ in 0..latency_samples { for _ in 0..latency_samples {
tx.send(0.0)?; // The ring buffer has twice as much space as necessary to add latency here,
// so this should never fail
producer.push(0.0).unwrap();
} }
// Play the streams. // Play the streams.
@ -66,7 +71,7 @@ fn main() -> Result<(), failure::Error> {
assert_eq!(id, input_stream_id); assert_eq!(id, input_stream_id);
let mut output_fell_behind = false; let mut output_fell_behind = false;
for &sample in buffer.iter() { for &sample in buffer.iter() {
if tx.try_send(sample).is_err() { if producer.push(sample).is_err() {
output_fell_behind = true; output_fell_behind = true;
} }
} }
@ -78,7 +83,7 @@ fn main() -> Result<(), failure::Error> {
assert_eq!(id, output_stream_id); assert_eq!(id, output_stream_id);
let mut input_fell_behind = None; let mut input_fell_behind = None;
for sample in buffer.iter_mut() { for sample in buffer.iter_mut() {
*sample = match rx.try_recv() { *sample = match consumer.pop() {
Ok(s) => s, Ok(s) => s,
Err(err) => { Err(err) => {
input_fell_behind = Some(err); input_fell_behind = Some(err);
@ -86,8 +91,8 @@ fn main() -> Result<(), failure::Error> {
}, },
}; };
} }
if let Some(err) = input_fell_behind { if let Some(_) = input_fell_behind {
eprintln!("input stream fell behind: {}: try increasing latency", err); eprintln!("input stream fell behind: try increasing latency");
} }
}, },
_ => panic!("we're expecting f32 data"), _ => panic!("we're expecting f32 data"),