Merge pull request #309 from ely-uf/feature/source_skip_duration

Add SkipDuration source.
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est31 2020-10-02 22:34:49 +02:00 committed by GitHub
commit 20a8f69e6b
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@ -21,6 +21,7 @@ pub use self::periodic::PeriodicAccess;
pub use self::repeat::Repeat; pub use self::repeat::Repeat;
pub use self::samples_converter::SamplesConverter; pub use self::samples_converter::SamplesConverter;
pub use self::sine::SineWave; pub use self::sine::SineWave;
pub use self::skip::SkipDuration;
pub use self::spatial::Spatial; pub use self::spatial::Spatial;
pub use self::speed::Speed; pub use self::speed::Speed;
pub use self::stoppable::Stoppable; pub use self::stoppable::Stoppable;
@ -45,6 +46,7 @@ mod periodic;
mod repeat; mod repeat;
mod samples_converter; mod samples_converter;
mod sine; mod sine;
mod skip;
mod spatial; mod spatial;
mod speed; mod speed;
mod stoppable; mod stoppable;
@ -195,6 +197,17 @@ where
delay::delay(self, duration) delay::delay(self, duration)
} }
/// Immediately skips a certain duration of this source.
///
/// If the specified duration is longer than the source itself, `skip_duration` will skip to the end of the source.
#[inline]
fn skip_duration(self, duration: Duration) -> SkipDuration<Self>
where
Self: Sized,
{
skip::skip_duration(self, duration)
}
/// Amplifies the sound by the given value. /// Amplifies the sound by the given value.
#[inline] #[inline]
fn amplify(self, value: f32) -> Amplify<Self> fn amplify(self, value: f32) -> Amplify<Self>

244
src/source/skip.rs Normal file
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@ -0,0 +1,244 @@
use crate::{Sample, Source};
use std::time::Duration;
const NS_PER_SECOND: u128 = 1_000_000_000;
/// Internal function that builds a `SkipDuration` object.
pub fn skip_duration<I>(mut input: I, duration: Duration) -> SkipDuration<I>
where
I: Source,
I::Item: Sample,
{
do_skip_duration(&mut input, duration);
SkipDuration {
input,
skipped_duration: duration,
}
}
/// Skips specified `duration` of the given `input` source from it's current position.
fn do_skip_duration<I>(input: &mut I, mut duration: Duration)
where
I: Source,
I::Item: Sample,
{
while duration > Duration::new(0, 0) {
if input.current_frame_len().is_none() {
// Sample rate and the amount of channels will be the same till the end.
do_skip_duration_unchecked(input, duration);
return;
}
// .unwrap() safety: if `current_frame_len()` is None, the body of the `if` statement
// above returns before we get here.
let frame_len: usize = input.current_frame_len().unwrap();
let ns_per_sample: u128 =
NS_PER_SECOND / input.sample_rate() as u128 / input.channels() as u128;
// Check if we need to skip only part of the current frame.
if frame_len as u128 * ns_per_sample > duration.as_nanos() {
skip_samples(input, (duration.as_nanos() / ns_per_sample) as usize);
return;
}
skip_samples(input, frame_len as usize);
duration -= Duration::from_nanos((frame_len * ns_per_sample as usize) as u64);
}
}
/// Skips specified `duration` from the `input` source assuming that sample rate
/// and amount of channels are not changing.
fn do_skip_duration_unchecked<I>(input: &mut I, duration: Duration)
where
I: Source,
I::Item: Sample,
{
let samples_per_channel: u128 =
duration.as_nanos() * input.sample_rate() as u128 / NS_PER_SECOND;
let samples_to_skip: u128 = samples_per_channel * input.channels() as u128;
skip_samples(input, samples_to_skip as usize);
}
/// Skips `n` samples from the given `input` source.
fn skip_samples<I>(input: &mut I, n: usize)
where
I: Source,
I::Item: Sample,
{
for _ in 0..n {
if input.next().is_none() {
break;
}
}
}
/// A source that skips specified duration of the given source from it's current position.
#[derive(Clone, Debug)]
pub struct SkipDuration<I> {
input: I,
skipped_duration: Duration,
}
impl<I> SkipDuration<I>
where
I: Source,
I::Item: Sample,
{
/// Returns a reference to the inner source.
#[inline]
pub fn inner(&self) -> &I {
&self.input
}
/// Returns a mutable reference to the inner source.
#[inline]
pub fn inner_mut(&mut self) -> &mut I {
&mut self.input
}
/// Returns the inner source.
#[inline]
pub fn into_inner(self) -> I {
self.input
}
}
impl<I> Iterator for SkipDuration<I>
where
I: Source,
I::Item: Sample,
{
type Item = <I as Iterator>::Item;
#[inline]
fn next(&mut self) -> Option<Self::Item> {
self.input.next()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.input.size_hint()
}
}
impl<I> Source for SkipDuration<I>
where
I: Source,
I::Item: Sample,
{
#[inline]
fn current_frame_len(&self) -> Option<usize> {
self.input.current_frame_len()
}
#[inline]
fn channels(&self) -> u16 {
self.input.channels()
}
#[inline]
fn sample_rate(&self) -> u32 {
self.input.sample_rate()
}
#[inline]
fn total_duration(&self) -> Option<Duration> {
self.input.total_duration().map(|val| {
val.checked_sub(self.skipped_duration)
.unwrap_or(Duration::from_secs(0))
})
}
}
#[cfg(test)]
mod tests {
use crate::buffer::SamplesBuffer;
use crate::source::Source;
use std::time::Duration;
fn test_skip_duration_samples_left(
channels: u16,
sample_rate: u32,
seconds: u32,
seconds_to_skip: u32,
) {
let data: Vec<f32> = (1..=(sample_rate * channels as u32 * seconds))
.map(|_| 0f32)
.collect();
let test_buffer = SamplesBuffer::new(channels, sample_rate, data);
let seconds_left = seconds.checked_sub(seconds_to_skip).unwrap_or(0);
let samples_left_expected = (sample_rate * channels as u32 * seconds_left) as usize;
let samples_left = test_buffer
.skip_duration(Duration::from_secs(seconds_to_skip as u64))
.count();
assert_eq!(samples_left, samples_left_expected);
}
macro_rules! skip_duration_test_block {
($(channels: $ch:expr, sample rate: $sr:expr, seconds: $sec:expr, seconds to skip: $sec_to_skip:expr;)+) => {
$(
test_skip_duration_samples_left($ch, $sr, $sec, $sec_to_skip);
)+
}
}
#[test]
fn skip_duration_shorter_than_source() {
skip_duration_test_block! {
channels: 1, sample rate: 44100, seconds: 5, seconds to skip: 3;
channels: 1, sample rate: 96000, seconds: 5, seconds to skip: 3;
channels: 2, sample rate: 44100, seconds: 5, seconds to skip: 3;
channels: 2, sample rate: 96000, seconds: 5, seconds to skip: 3;
channels: 4, sample rate: 44100, seconds: 5, seconds to skip: 3;
channels: 4, sample rate: 96000, seconds: 5, seconds to skip: 3;
}
}
#[test]
fn skip_duration_zero_duration() {
skip_duration_test_block! {
channels: 1, sample rate: 44100, seconds: 5, seconds to skip: 0;
channels: 1, sample rate: 96000, seconds: 5, seconds to skip: 0;
channels: 2, sample rate: 44100, seconds: 5, seconds to skip: 0;
channels: 2, sample rate: 96000, seconds: 5, seconds to skip: 0;
channels: 4, sample rate: 44100, seconds: 5, seconds to skip: 0;
channels: 4, sample rate: 96000, seconds: 5, seconds to skip: 0;
}
}
#[test]
fn skip_duration_longer_than_source() {
skip_duration_test_block! {
channels: 1, sample rate: 44100, seconds: 1, seconds to skip: 5;
channels: 1, sample rate: 96000, seconds: 10, seconds to skip: 11;
channels: 2, sample rate: 44100, seconds: 1, seconds to skip: 5;
channels: 2, sample rate: 96000, seconds: 10, seconds to skip: 11;
channels: 4, sample rate: 44100, seconds: 1, seconds to skip: 5;
channels: 4, sample rate: 96000, seconds: 10, seconds to skip: 11;
}
}
#[test]
fn skip_duration_equal_to_source_length() {
skip_duration_test_block! {
channels: 1, sample rate: 44100, seconds: 1, seconds to skip: 1;
channels: 1, sample rate: 96000, seconds: 10, seconds to skip: 10;
channels: 2, sample rate: 44100, seconds: 1, seconds to skip: 1;
channels: 2, sample rate: 96000, seconds: 10, seconds to skip: 10;
channels: 4, sample rate: 44100, seconds: 1, seconds to skip: 1;
channels: 4, sample rate: 96000, seconds: 10, seconds to skip: 10;
}
}
}