Jake
0ea230fef4
CRITICAL from the 2026-04-22 code review: RmsVadChunker::flush() was calling consume_frame() on a zero-padded final frame via `let _ = ...`, discarding any VadChunk the call emitted. If the padded frame triggered end-of-utterance (silent tail + padding zeros push past silence_close_samples) or max_chunk_samples (buffered speech + padding push past the cap), the emitted chunk was lost; the outer state check then either returned None or an empty closing chunk. Changes the VadChunker trait flush signature from Option<VadChunk> to Vec<VadChunk> so both the mid-flush emission (from consume_frame) and the closing emission (from emit_active_chunk_and_close) can be surfaced. Updates RmsVadChunker::flush to collect from both sites and skip a zero-length closing emit when the hit_max continue variant already cleared active_chunk. Two regression tests land alongside: - flush_preserves_hit_max_chunk_from_padded_final_frame: tight max_chunk, sub-frame speech tail; pre-fix dropped the chunk, post-fix emitted samples cover the full active-speech region. - flush_preserves_end_of_utterance_chunk_from_padded_final_frame: silent tail near silence_close; padded zero frame closes the utterance inside consume_frame; pre-fix returned None. No production callers yet — the VadChunker wiring in live.rs is a deferred item from A.3. API change is clean within the repo.
84 lines
3.3 KiB
Rust
84 lines
3.3 KiB
Rust
//! Streaming primitives for live capture: VAD-gated chunking,
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//! agreement-based commit policy, and bounded buffer management.
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//!
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//! These types are tested at the unit level. Integration into
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//! `src-tauri/src/commands/live.rs` lands in follow-up commits so
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//! threshold tuning can be validated against real microphone captures
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//! rather than synthetic fixtures (brief items #21, #24, #25).
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pub mod buffer_trim;
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pub mod commit_policy;
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pub mod rms_vad;
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pub use buffer_trim::{sample_index_for_seconds, trim_buffer_to_commit_point};
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pub use commit_policy::{CommitDecision, CommitPolicy, LocalAgreement, Token};
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pub use rms_vad::RmsVadChunker;
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/// A span of audio the VAD considers worth transcribing. `start_sample`
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/// is an absolute index into the stream the `VadChunker` has been fed
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/// since its last `reset`; `samples` is f32 PCM at the chunker's
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/// configured sample rate.
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#[derive(Debug, Clone)]
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pub struct VadChunk {
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pub start_sample: u64,
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pub samples: Vec<f32>,
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}
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/// A streaming VAD-gated chunker.
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///
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/// Implementations accumulate incoming samples, decide whether the
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/// current segment is speech using a score + hysteresis (brief item
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/// #21), and emit `VadChunk`s when a speech region ends — or when an
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/// in-progress speech region exceeds the configured max length so
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/// Whisper is not fed a 30-second monolith.
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///
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/// `push` returns any chunks ready to dispatch; typical usage is
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/// `for chunk in chunker.push(&samples) { dispatch(chunk); }` inside
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/// the capture loop.
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///
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/// `flush` is called at end-of-session to emit any in-flight speech as
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/// a final chunk (even if silence hasn't closed it).
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///
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/// `Send` because a chunker is owned by the live-session worker thread
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/// and moved into `spawn_blocking`.
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pub trait VadChunker: Send {
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/// Feed new samples. Returns any chunks the chunker has decided to
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/// emit as a result. An empty Vec means "still gathering".
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fn push(&mut self, samples: &[f32]) -> Vec<VadChunk>;
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/// End-of-session: emit any in-progress speech as chunks even
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/// though silence has not closed them. Returns an empty Vec if
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/// there is nothing buffered (or only sub-threshold samples).
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///
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/// Returns `Vec<VadChunk>` rather than `Option<VadChunk>` because
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/// the zero-padded final frame can legitimately trigger both a
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/// mid-flush emission (end-of-utterance or `max_chunk_samples`)
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/// AND a closing emission if the backend stays in-speech after
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/// the mid-flush cut. The previous `Option` signature silently
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/// dropped the mid-flush chunk.
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fn flush(&mut self) -> Vec<VadChunk>;
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/// Drop accumulated state. Used between sessions on the same
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/// chunker instance (or after a context-window reset from the
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/// repetition detector — brief item #26).
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fn reset(&mut self);
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/// Absolute sample index of the next sample that will be fed via
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/// `push`. Exposed so the commit policy (#24) can compute sample
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/// offsets for its agreement window.
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fn next_sample_index(&self) -> u64;
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn vad_chunker_trait_is_object_safe() {
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// Compile-time witness: keep the trait dyn-compatible so the
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// live-session worker can hold `Box<dyn VadChunker>` and swap
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// between RMS and Silero backends at runtime.
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let _: Option<Box<dyn VadChunker>> = None;
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}
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}
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