Add VAD example

examples/vad.rs

@@ -0,0 +1,59 @@
+use hound::SampleFormat;
+use std::io::Read;
+use whisper_rs::{WhisperVadContext, WhisperVadContextParams, WhisperVadParams, WhisperVadSegment};
+
+fn main() {
+    let model_path = std::env::args()
+        .nth(1)
+        .expect("Please specify path to VAD model as argument 1");
+    let wav_path = std::env::args()
+        .nth(2)
+        .expect("Please specify path to WAV file as argument 2");
+
+    let wav_reader = hound::WavReader::open(wav_path).expect("failed to open wav file");
+    assert_eq!(
+        wav_reader.spec().sample_rate,
+        16000,
+        "expected 16kHz sample rate"
+    );
+    assert_eq!(wav_reader.spec().channels, 1, "expected mono audio");
+
+    let samples = decode_to_float(wav_reader);
+
+    let mut vad_ctx_params = WhisperVadContextParams::default();
+    vad_ctx_params.set_n_threads(1);
+    vad_ctx_params.set_use_gpu(false);
+
+    // Note this context could be held in a global Mutex or similar
+    // There's no restrictions on where the output can be sent after it's used,
+    // as it just holds a C-style array internally with no references to the model.
+    let mut vad_ctx =
+        WhisperVadContext::new(&model_path, vad_ctx_params).expect("failed to load model");
+
+    let vad_params = WhisperVadParams::new();
+    let result = vad_ctx
+        .segments_from_samples(vad_params, &samples)
+        .expect("failed to run VAD");
+
+    for WhisperVadSegment { start, end } in result {
+        println!(
+            "detected speech between {}s and {}s",
+            // each segment is in centiseconds so must be modified
+            start / 100.0,
+            end / 100.0
+        );
+    }
+}
+
+fn decode_to_float<T: Read>(rdr: hound::WavReader<T>) -> Vec<f32> {
+    match rdr.spec().sample_format {
+        SampleFormat::Float => rdr
+            .into_samples::<f32>()
+            .map(|x| x.expect("expected fp32 WAV file"))
+            .collect(),
+        SampleFormat::Int => rdr
+            .into_samples::<i16>()
+            .map(|x| x.expect("expected i16 WAV file") as f32 / 32768.0)
+            .collect(),
+    }
+}