cjpais/Handy · critical

Failed to create resampler

Error message

Failed to create resampler

What it means

A panic (expect) inside FrameResampler::new when rubato's FftFixedIn::new returns Err for the given in_hz/out_hz/chunk_in combination. FftFixedIn validates its arguments — zero sample rates or a fixed chunk size that cannot map to a valid FFT length for the in-to-out ratio produce an Err, which this code converts into a process abort. Because it is an expect, there is no Result to handle.

Source

Thrown at src-tauri/src/audio_toolkit/audio/resampler.rs:31

    in_hz: usize,
    out_hz: usize,
    /// Samples in/out of the inner resampler; `finish()` uses the pair to
    /// know how much real audio (~10-30ms) its delay line still holds.
    in_count: usize,
    out_count: usize,
}

impl FrameResampler {
    pub fn new(in_hz: usize, out_hz: usize, frame_dur: Duration) -> Self {
        let frame_samples = ((out_hz as f64 * frame_dur.as_secs_f64()).round()) as usize;
        assert!(frame_samples > 0, "frame duration too short");

        // Use fixed chunk size instead of GCD-based
        let chunk_in = RESAMPLER_CHUNK_SIZE;

        let resampler = (in_hz != out_hz).then(|| {
            FftFixedIn::<f32>::new(in_hz, out_hz, chunk_in, 1, 1)
                .expect("Failed to create resampler")
        });

        Self {
            resampler,
            chunk_in,
            in_buf: Vec::with_capacity(chunk_in),
            frame_samples,
            pending: Vec::with_capacity(frame_samples),
            in_hz,
            out_hz,
            in_count: 0,
            out_count: 0,
        }
    }

    pub fn push(&mut self, mut src: &[f32], mut emit: impl FnMut(&[f32])) {
        if self.resampler.is_none() {
            self.emit_frames(src, &mut emit);

View on GitHub (pinned to c6fa60da2f)

Solutions

1. Log in_hz/out_hz at construction and treat 0 or absurd rates from the device config as a config-fetch failure (the code already drops a stale cache on open failure, so retry re-queries)
2. Pick a chunk_in compatible with the actual ratios; add a unit test constructing the resampler for every device rate you support at the target rate
3. Keep the in_hz == out_hz passthrough path so only genuine resamples reach FftFixedIn
4. Replace .expect with fallible construction (map_err into an io::Error) so callers can fail gracefully instead of aborting

Example fix

// before
let resampler = (in_hz != out_hz).then(|| {
    FftFixedIn::<f32>::new(in_hz, out_hz, chunk_in, 1, 1)
        .expect("Failed to create resampler")
});

// after — construction becomes fallible instead of aborting the process
let resampler = (in_hz != out_hz)
    .then(|| FftFixedIn::<f32>::new(in_hz, out_hz, chunk_in, 1, 1))
    .transpose()
    .map_err(|e| {
        std::io::Error::new(
            std::io::ErrorKind::InvalidInput,
            format!("resampler {in_hz}->{out_hz} chunk {chunk_in}: {e}"),
        )
    })?;

// Validate rates and chunk compatibility before constructing the resampler
if in_hz == 0 || out_hz == 0 {
    return Err(std::io::Error::new(
        std::io::ErrorKind::InvalidInput,
        format!("invalid sample rate {in_hz}->{out_hz}"),
    ));
}
if in_hz != out_hz {
    rubato::FftFixedIn::<f32>::new(in_hz, out_hz, RESAMPLER_CHUNK_SIZE, 1, 1)
        .map_err(|e| format!("chunk {RESAMPLER_CHUNK_SIZE} invalid for {in_hz}->{out_hz}: {e}"))?;
}

When it happens

Trigger: Constructing FrameResampler with in_hz != out_hz while RESAMPLER_CHUNK_SIZE is not a usable chunk for that ratio, or with a garbage/zero sample rate coming from the device config (e.g. a cached config or device query that returned 0 Hz).

Common situations: A device reporting an unusual native rate (8000/11025 Hz) that the fixed chunk cannot express for the 16000 Hz target; corrupted or zero sample_rate from the config cache after a device changed state; changing RESAMPLER_CHUNK_SIZE or the output rate without validating FFT compatibility for all real devices.

Related errors

• Failed to initialize recording manager
• English translations must exist
• No input device found
• {error_message}
• Failed to create AudioRecorder: {}

AI-assisted analysis of cjpais/Handy@c6fa60da2f (2026-08-17). Data as JSON: /api/errors/3f116ad91a94d89d. Report an issue: GitHub.