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fix(audio): support i8 sample format #21

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fix(audio): support i8 sample format #21

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2 changes: 2 additions & 0 deletions keyless-audio/src/input/api.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -176,6 +176,8 @@ pub fn can_record() -> bool {

let sc: cpal::StreamConfig = cfg.config().clone();
let result = match cfg.sample_format() {
cpal::SampleFormat::I8 => try_build::<i8>(&device, sc),
cpal::SampleFormat::U8 => try_build::<u8>(&device, sc),
cpal::SampleFormat::I16 => try_build::<i16>(&device, sc),
cpal::SampleFormat::U16 => try_build::<u16>(&device, sc),
cpal::SampleFormat::F32 => try_build::<f32>(&device, sc),
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43 changes: 43 additions & 0 deletions keyless-audio/src/input/cpal.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -231,6 +231,49 @@ impl CpalAudioInput {
err_fn,
None,
),
cpal::SampleFormat::I8 => device.build_input_stream(
&chosen.config(),
move |data: &[i8], _| {
// Convert i8 [-128, 127] to f32 [-1.0, 1.0] via division by MAX.
// Cast to f32 before division to avoid integer overflow.
if let Ok(mut state) = shared_clone.lock() {
let frame_samples = state.1;
let buf = &mut state.0;
for &s in data.iter() {
buf.push(s as f32 / i8::MAX as f32);
}
// Drain complete frames; may emit multiple frames if buffer accumulated enough.
while buf.len() >= frame_samples {
let frame: Vec<f32> = buf.drain(0..frame_samples).collect();
let _ = tx.try_send(frame);
}
}
},
err_fn,
None,
),
cpal::SampleFormat::U8 => device.build_input_stream(
&chosen.config(),
move |data: &[u8], _| {
// Convert u8 [0, 255] to f32 [-1.0, 1.0]: normalize to [0, 1], then shift.
// Formula: (s / MAX) * 2.0 - 1.0 maps 0→-1.0, 127→0.0, 255.0.
if let Ok(mut state) = shared_clone.lock() {
let frame_samples = state.1;
let buf = &mut state.0;
for &s in data.iter() {
let f = (s as f32 / u8::MAX as f32) * 2.0 - 1.0;
buf.push(f);
}
// Drain complete frames; may emit multiple frames if buffer accumulated enough.
while buf.len() >= frame_samples {
let frame: Vec<f32> = buf.drain(0..frame_samples).collect();
let _ = tx.try_send(frame);
}
}
},
err_fn,
None,
),
_ => {
// Reject unsupported formats (I24, I32, F64, etc.) upfront.
return Err(keyless_core::error::KeylessError::Audio(
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