Add OpenVINO support

src/whisper_ctx.rs

@@ -56,6 +56,44 @@ impl WhisperContext {
 
     // we don't implement `whisper_init()` here since i have zero clue what `whisper_model_loader` does
 
+    /// Using this context, enable use of OpenVINO for encoder inference.
+    ///
+    /// # Arguments
+    /// * `model_path`: An optional path to the OpenVINO encoder IR model.
+    /// If set to `None`,
+    /// the path will be generated from the ggml model path
+    /// that was passed in to whisper_init_from_file.
+    /// For example, if the model path was "/path/to/ggml-base.en.bin",
+    /// then the OpenVINO IR model path will be assumed as "/path/to/ggml-base.en-encoder-openvino.xml".
+    ///
+    /// * `device`: The OpenVINO device to use for inference (e.g. "CPU", "GPU")
+    ///
+    /// * `cache_dir`: Optional cache directory that can speed up init time,
+    /// especially for GPU, by caching compiled 'blobs' there.
+    /// Set to nullptr if not used.
+    ///
+    /// # Returns
+    /// `true` on success, `false` if OpenVINO was not enabled at compile time
+    /// (enable the `openvino` feature flag in your Cargo.toml).
+    ///
+    /// # C++ equivalent
+    /// `int whisper_ctx_init_openvino_encoder(struct whisper_context * ctx, const char * model_path, const char * device, const char * cache_dir);`
+    #[cfg(feature = "openvino")]
+    pub fn init_openvino_encoder(&mut self, model_path: Option<&str>, device: &str, cache_dir: Option<&str>) -> bool {
+        let model_path = model_path.map(|s| CString::new(s).unwrap());
+        let device = CString::new(device).unwrap();
+        let cache_dir = cache_dir.map(|s| CString::new(s).unwrap());
+        let ret = unsafe {
+            whisper_rs_sys::whisper_ctx_init_openvino_encoder(
+                self.ctx,
+                model_path.map(|s| s.as_ptr()).unwrap_or(std::ptr::null()),
+                device.as_ptr(),
+                cache_dir.map(|s| s.as_ptr()).unwrap_or(std::ptr::null()),
+            )
+        };
+        ret != 0
+    }
+
     /// Create a new state object, ready for use.
     ///
     /// # Returns