feat: add WhisperKit transcriber and transcribe probe

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
2026-10-01 09:48:17 +02:00
parent 28515d9c87
commit ee8d56c2fb
5 changed files with 149 additions and 2 deletions
@@ -0,0 +1,40 @@
+import Foundation
+import SstCore
+import WhisperKit
+
+public final class WhisperKitTranscriber: Transcriber {
+    public enum TranscriberError: Error, LocalizedError {
+        case notLoaded
+
+        public var errorDescription: String? { "Spraakmodel is nog niet geladen." }
+    }
+
+    private let modelName: String
+    private var pipeline: WhisperKit?
+
+    public init(model: String = "large-v3-v20240930_turbo") {
+        self.modelName = model
+    }
+
+    /// Downloads the model on first run (≈1.5 GB) and loads it into memory.
+    public func load() async throws {
+        pipeline = try await WhisperKit(WhisperKitConfig(model: modelName))
+    }
+
+    public func transcribe(_ samples: [Float]) async throws -> String {
+        guard let pipeline else { throw TranscriberError.notLoaded }
+        // language nil + detectLanguage: Whisper picks NL or EN per utterance.
+        let options = DecodingOptions(
+            task: .transcribe,
+            language: nil,
+            detectLanguage: true,
+            skipSpecialTokens: true,
+            withoutTimestamps: true
+        )
+        let results = try await pipeline.transcribe(audioArray: samples, decodeOptions: options)
+        return results
+            .map(\.text)
+            .joined(separator: " ")
+            .trimmingCharacters(in: .whitespacesAndNewlines)
+    }
+}