Text-to-speech for iOS (#443)

ios-swiftui/SherpaOnnxTts/SherpaOnnxTts/ViewModel.swift

@@ -0,0 +1,68 @@
+//
+//  ViewModel.swift
+//  SherpaOnnxTts
+//
+//  Created by fangjun on 2023/11/23.
+//
+
+import Foundation
+
+func getResource(_ forResource: String, _ ofType: String) -> String {
+  let path = Bundle.main.path(forResource: forResource, ofType: ofType)
+  precondition(
+    path != nil,
+    "\(forResource).\(ofType) does not exist!\n" + "Remember to change \n"
+      + "  Build Phases -> Copy Bundle Resources\n" + "to add it!"
+  )
+  return path!
+}
+
+/// Please refer to
+/// https://k2-fsa.github.io/sherpa/onnx/tts/pretrained_models/index.html
+/// to download pre-trained models
+
+func getTtsForVCTK() -> SherpaOnnxOfflineTtsWrapper {
+  // See the following link
+  // https://k2-fsa.github.io/sherpa/onnx/tts/pretrained_models/vits.html#vctk-english-multi-speaker-109-speakers
+
+  // vits-vctk.onnx
+  let model = getResource("vits-vctk", "onnx")
+
+  // lexicon.txt
+  let lexicon = getResource("lexicon", "txt")
+
+  // tokens.txt
+  let tokens = getResource("tokens", "txt")
+
+  let vits = sherpaOnnxOfflineTtsVitsModelConfig(model: model, lexicon: lexicon, tokens: tokens)
+  let modelConfig = sherpaOnnxOfflineTtsModelConfig(vits: vits)
+  var config = sherpaOnnxOfflineTtsConfig(model: modelConfig)
+  return SherpaOnnxOfflineTtsWrapper(config: &config)
+}
+
+func getTtsForAishell3() -> SherpaOnnxOfflineTtsWrapper {
+  // See the following link
+  // https://k2-fsa.github.io/sherpa/onnx/tts/pretrained_models/vits.html#vits-model-aishell3
+
+  // vits-vctk.onnx
+  let model = getResource("vits-aishell3", "onnx")
+
+  // lexicon.txt
+  let lexicon = getResource("lexicon", "txt")
+
+  // tokens.txt
+  let tokens = getResource("tokens", "txt")
+
+  let vits = sherpaOnnxOfflineTtsVitsModelConfig(model: model, lexicon: lexicon, tokens: tokens)
+  let modelConfig = sherpaOnnxOfflineTtsModelConfig(vits: vits)
+  var config = sherpaOnnxOfflineTtsConfig(model: modelConfig)
+  return SherpaOnnxOfflineTtsWrapper(config: &config)
+}
+
+func createOfflineTts() -> SherpaOnnxOfflineTtsWrapper {
+  return getTtsForVCTK()
+
+  // return getTtsForAishell3()
+
+  // please add more models on need by following the above two examples
+}