114 lines
3.1 KiB
Rust
114 lines
3.1 KiB
Rust
const SYNC_LENGHT: usize = 40;
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const SYNCA_SEQ: [bool; 40] = [
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false, false, false, false, true, true, false, false, // Pulse 1
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true, true, false, false, // Pulse 2
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true, true, false, false, // Pulse 3
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true, true, false, false, // Pulse 4
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true, true, false, false, // Pulse 5
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true, true, false, false, // Pulse 6
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true, true, false, false, // Pulse 7
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false, false, false, false, false, false, false, false,
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];
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const SYNCB_SEQ: [bool; 40] = [
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false, false, false, false, true, true, true, false, false, true, true, true, false, false,
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true, true, true, false, false, true, true, true, false, false, true, true, true, false, false,
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true, true, true, false, false, true, true, true, false, false, false,
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];
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pub enum SyncedSample {
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Sample(f32),
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SyncA(f32),
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SyncB(f32),
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}
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pub struct APTSyncer<'a> {
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state: [f32; SYNC_LENGHT],
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pos: usize,
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nones_read: usize,
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avg_level: f32,
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iterator: Box<dyn Iterator<Item = f32> + 'a>,
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}
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impl<'a> APTSyncer<'a> {
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pub fn from<I>(mut iterator: I) -> APTSyncer<'a>
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where
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I: Iterator<Item = f32> + 'a,
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{
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let mut state = [0.0; SYNC_LENGHT];
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let mut avg_level = 0.5;
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for i in 0..SYNC_LENGHT {
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match iterator.next() {
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Some(x) => {
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state[i] = x;
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avg_level = 0.25 * x + avg_level * 0.75;
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}
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None => panic!("Could not retrieve enough samples to prime syncer"),
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}
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}
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APTSyncer {
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state,
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pos: 0,
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nones_read: 0,
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avg_level,
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iterator: Box::new(iterator),
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}
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}
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fn is_marker(&mut self) -> (bool, bool) {
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let mut count_a = 0;
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let mut count_b = 0;
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for i in 0..SYNC_LENGHT {
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let sync_pos = (self.pos + i) % SYNC_LENGHT;
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let sample = self.state[sync_pos] / (self.avg_level * 2.0);
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if (sample > 0.5 && SYNCA_SEQ[i]) || (sample <= 0.5 && !SYNCA_SEQ[i]) {
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count_a += 1;
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}
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if (sample > 0.5 && SYNCB_SEQ[i]) || (sample <= 0.5 && !SYNCB_SEQ[i]) {
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count_b += 1;
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}
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/*
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if !count_a && !count_b {
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break;
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}
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*/
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}
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return (count_a > 35, count_b > 35);
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}
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}
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impl<'a> Iterator for APTSyncer<'a> {
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type Item = SyncedSample;
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fn next(&mut self) -> Option<Self::Item> {
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let (is_a, is_b) = self.is_marker();
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let sample = self.state[self.pos];
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match self.iterator.next() {
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Some(x) => {
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self.state[self.pos] = x;
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self.avg_level = 0.25 * x + self.avg_level * 0.75;
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}
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None => self.nones_read += 1,
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};
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if self.nones_read >= SYNC_LENGHT {
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return None;
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}
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self.pos = (self.pos + 1) % SYNC_LENGHT;
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if is_a {
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return Some(SyncedSample::SyncA(sample));
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} else if is_b {
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return Some(SyncedSample::SyncB(sample));
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} else {
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return Some(SyncedSample::Sample(sample));
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}
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}
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}
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