feat: upgrade silero backend to v6.2.1

README.md

@@ -198,14 +198,22 @@ let cleaned = preprocessor.process(&raw_audio);
 
 ### ONNX Model Downloads
 
-Silero, TEN-VAD, and FireRedVAD models are downloaded automatically at build time. For offline or CI builds, point to a local model file:
+Silero, TEN-VAD, and FireRedVAD models are downloaded automatically at build time. The Silero backend is pinned to **v6.2.1** by default.
+
+For offline or CI builds, point to a local model file:
 
 ```sh
 SILERO_MODEL_PATH=/path/to/silero_vad.onnx cargo build --features silero
 TEN_VAD_MODEL_PATH=/path/to/ten-vad.onnx cargo build --features ten-vad
 FIRERED_MODEL_PATH=/path/to/fireredvad.onnx FIRERED_CMVN_PATH=/path/to/cmvn.ark cargo build --features firered
 ```
 
+To use a different Silero model version, override the download URL:
+
+```sh
+SILERO_MODEL_URL=https://github.com/snakers4/silero-vad/raw/v6.0/src/silero_vad/data/silero_vad.onnx cargo build --features silero
+```
+
 ## Error Handling
 
 All backends return `Result<f32, VadError>`. The error type covers:

crates/wavekat-vad/build.rs

@@ -63,15 +63,18 @@ fn main() {
 #[cfg(feature = "silero")]
 fn setup_silero_model() {
     const DEFAULT_MODEL_URL: &str =
-        "https://github.com/snakers4/silero-vad/raw/master/src/silero_vad/data/silero_vad.onnx";
+        "https://github.com/snakers4/silero-vad/raw/v6.2.1/src/silero_vad/data/silero_vad.onnx";
     const SILERO_MODEL_NAME: &str = "silero_vad.onnx";
+    // Bump this when updating the default model URL to invalidate cached downloads.
+    const SILERO_MODEL_VERSION: &str = "v6.2.1";
 
     // Re-run if these env vars change
     println!("cargo:rerun-if-env-changed=SILERO_MODEL_PATH");
     println!("cargo:rerun-if-env-changed=SILERO_MODEL_URL");
 
     let out_dir = env::var("OUT_DIR").expect("OUT_DIR not set");
     let model_path = Path::new(&out_dir).join(SILERO_MODEL_NAME);
+    let version_path = Path::new(&out_dir).join("silero_vad.version");
 
     // Option 1: Use local file if SILERO_MODEL_PATH is set
     if let Ok(local_path) = env::var("SILERO_MODEL_PATH") {
@@ -91,8 +94,9 @@ fn setup_silero_model() {
         return;
     }
 
-    // Skip download if already exists
-    if model_path.exists() {
+    // Skip download if model exists and version matches
+    let cached_version = fs::read_to_string(&version_path).unwrap_or_default();
+    if model_path.exists() && cached_version.trim() == SILERO_MODEL_VERSION {
         return;
     }
 
@@ -111,9 +115,10 @@ fn setup_silero_model() {
         .expect("failed to read model bytes");
 
     fs::write(&model_path, &bytes).expect("failed to write model file");
+    fs::write(&version_path, SILERO_MODEL_VERSION).expect("failed to write version marker");
 
     println!(
-        "cargo:warning=Silero VAD model downloaded to {}",
+        "cargo:warning=Silero VAD model ({SILERO_MODEL_VERSION}) downloaded to {}",
         model_path.display()
     );
 }

crates/wavekat-vad/src/backends/silero.rs

@@ -1,7 +1,7 @@
 //! Silero VAD backend using ONNX Runtime.
 //!
 //! This backend wraps the [Silero VAD](https://github.com/snakers4/silero-vad)
-//! v5 model, a pre-trained LSTM neural network for voice activity detection.
+//! v6 model, a pre-trained LSTM neural network for voice activity detection.
 //! It runs inference via ONNX Runtime (through the [`ort`](https://crates.io/crates/ort)
 //! crate) and returns continuous speech probability scores between 0.0 and 1.0.
 //!
@@ -24,7 +24,7 @@
 //!
 //! # Model Loading
 //!
-//! The default ONNX model (Silero VAD v5) is embedded in the binary at
+//! The default ONNX model (Silero VAD v6) is embedded in the binary at
 //! compile time — no external files are needed at runtime. For custom
 //! models, use [`SileroVad::from_file`] or [`SileroVad::from_memory`].
 //!
@@ -47,7 +47,7 @@ use ndarray::{Array1, Array2, Array3};
 use ort::{inputs, session::Session, value::Tensor};
 use std::time::{Duration, Instant};
 
-/// Embedded Silero VAD ONNX model (v5).
+/// Embedded Silero VAD ONNX model (v6).
 /// Downloaded automatically at build time by build.rs.
 const MODEL_BYTES: &[u8] = include_bytes!(concat!(env!("OUT_DIR"), "/silero_vad.onnx"));
 
@@ -57,7 +57,7 @@ const CONTEXT_SIZE: usize = 64;
 /// LSTM hidden state shape: [2, 1, 128] (h and c states).
 const STATE_DIM: usize = 128;
 
-/// Voice activity detector backed by the Silero VAD v5 ONNX model.
+/// Voice activity detector backed by the Silero VAD v6 ONNX model.
 ///
 /// Uses an LSTM neural network to produce continuous speech probability
 /// scores (0.0–1.0). Internal hidden state and a context buffer persist

crates/wavekat-vad/src/lib.rs

@@ -110,15 +110,24 @@
 //! ## ONNX model downloads
 //!
 //! The Silero, TEN-VAD, and FireRedVAD backends download their ONNX models
-//! automatically at build time. For offline or CI builds, set environment
-//! variables to point to local model files:
+//! automatically at build time. The Silero backend is pinned to **v6.2.1** by
+//! default.
+//!
+//! For offline or CI builds, set environment variables to point to local model
+//! files:
 //!
 //! ```sh
 //! SILERO_MODEL_PATH=/path/to/silero_vad.onnx cargo build --features silero
 //! TEN_VAD_MODEL_PATH=/path/to/ten-vad.onnx cargo build --features ten-vad
 //! FIRERED_MODEL_PATH=/path/to/model.onnx FIRERED_CMVN_PATH=/path/to/cmvn.ark cargo build --features firered
 //! ```
 //!
+//! To use a different Silero model version, override the download URL:
+//!
+//! ```sh
+//! SILERO_MODEL_URL=https://github.com/snakers4/silero-vad/raw/v6.0/src/silero_vad/data/silero_vad.onnx cargo build --features silero
+//! ```
+//!
 //! # Error handling
 //!
 //! All backends return [`Result<f32, VadError>`]. Check a backend's