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updates from testing

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sigil-03 2025-11-06 19:11:29 -07:00
parent ba25b7c89f
commit 99ce71e8d0
1 changed files with 42 additions and 29 deletions
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51
src/dac.rs
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@ -5,7 +5,6 @@ pub enum Direction {
Down,
}
pub struct DpcmSample {
direction: Direction,
// only 3 bits
@ -84,8 +83,8 @@ impl<'a, T: DacInterface> DpcmDac<'a, T> {
index: 0,
prev_amplitude: 0x80,
step_size: 0x3,
min: 0x19,
max: 0xe6,
min: 0x25,
max: 0xc8,
}
}
pub fn load_data(&mut self, data: &'a [u8]) {
@ -102,8 +101,13 @@ impl<'a, T: DacInterface> DpcmDac<'a, T> {
let sample = DpcmSample::new(data[self.index / 2], sub_index);
let new_amplitude = match sample.direction {
Direction::Down => self.prev_amplitude.saturating_sub(sample.step_count as usize * self.step_size).max(self.min),
Direction ::Up => (self.prev_amplitude + (sample.step_count as usize * self.step_size)).min(self.max),
Direction::Down => self
.prev_amplitude
.saturating_sub(sample.step_count as usize * self.step_size)
.max(self.min),
Direction::Up => (self.prev_amplitude
+ (sample.step_count as usize * self.step_size))
.min(self.max),
};
// calculate normalized amplitude and write out
@ -111,13 +115,12 @@ impl<'a, T: DacInterface> DpcmDac<'a, T> {
self.output.write_amplitude(normalized_amplitude as u8);
self.prev_amplitude = new_amplitude;
// increment the sample index
let mut samples_remaining = true;
self.index = self.index + 1;
// reset the index to 0 if we roll over
if (self.index >= data.len() * 2) {
if (self.index >= data.len() * 2) {
self.index = 0;
self.prev_amplitude = 0x74;
samples_remaining = false;
@ -125,8 +128,7 @@ impl<'a, T: DacInterface> DpcmDac<'a, T> {
// return whether or not we have samples remaining
samples_remaining
}
else {
} else {
// if the sample failed to load, we (duh) have no more samples remaining
false
}
@ -137,8 +139,6 @@ impl<'a, T: DacInterface> DpcmDac<'a, T> {
}
}
pub struct DpcmDecoder<'a> {
data: Option<&'a [u8]>,
index: usize,
@ -153,10 +153,10 @@ impl<'a> DpcmDecoder<'a> {
Self {
data: None,
index: 0,
prev_amplitude: 0x80,
prev_amplitude: 0x0,
step_size: 0x3,
min: 0x19,
max: 0xe6,
min: 0x50,
max: 0xaa,
}
}
pub fn load_data(&mut self, data: &'a [u8]) {
@ -166,10 +166,18 @@ impl<'a> DpcmDecoder<'a> {
self.index = index;
}
pub fn is_done(&self) -> bool {
if let Some(data) = self.data {
self.index >= (data.len() * 2) - 1
} else {
false
}
}
// output the next sample's amplitude
pub fn output_next(&mut self) -> usize {
if let Some(data) = self.data {
if (self.index >= data.len() * 2) {
if self.index >= (data.len() * 2) - 10 {
return 0;
}
@ -177,16 +185,21 @@ impl<'a> DpcmDecoder<'a> {
let sample = DpcmSample::new(data[self.index / 2], sub_index);
let new_amplitude = match sample.direction {
Direction::Down => self.prev_amplitude.saturating_sub(sample.step_count as usize * self.step_size).max(self.min),
Direction ::Up => (self.prev_amplitude + (sample.step_count as usize * self.step_size)).min(self.max),
Direction::Down => self
.prev_amplitude
.saturating_sub(sample.step_count as usize * self.step_size)
.max(self.min),
Direction::Up => (self.prev_amplitude
+ (sample.step_count as usize * self.step_size))
.min(self.max),
};
// calculate normalized amplitude
// TODO: e4c811653781e69e40b63fd27a8c1e20
let normalized_amplitude = (new_amplitude - self.min) * 100 / (self.max - self.min);
let normalized_amplitude =
(new_amplitude.saturating_sub(self.min)) * 100 / (self.max - self.min);
self.prev_amplitude = new_amplitude;
// increment the sample index
let mut samples_remaining = true;
self.index = self.index + 1;