Add C API for Kokoro TTS models (#1717)

c-api-examples/CMakeLists.txt

@@ -13,6 +13,9 @@ if(SHERPA_ONNX_ENABLE_TTS)
 
   add_executable(matcha-tts-en-c-api matcha-tts-en-c-api.c)
   target_link_libraries(matcha-tts-en-c-api sherpa-onnx-c-api)
+
+  add_executable(kokoro-tts-en-c-api kokoro-tts-en-c-api.c)
+  target_link_libraries(kokoro-tts-en-c-api sherpa-onnx-c-api)
 endif()
 
 if(SHERPA_ONNX_ENABLE_SPEAKER_DIARIZATION)

c-api-examples/kokoro-tts-en-c-api.c

@@ -0,0 +1,84 @@
+// c-api-examples/kokoro-tts-en-c-api.c
+//
+// Copyright (c)  2025  Xiaomi Corporation
+
+// This file shows how to use sherpa-onnx C API
+// for English TTS with Kokoro.
+//
+// clang-format off
+/*
+Usage
+
+
+wget https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/kokoro-en-v0_19.tar.bz2
+tar xf kokoro-en-v0_19.tar.bz2
+rm kokoro-en-v0_19.tar.bz2
+
+./kokoro-tts-en-c-api
+
+ */
+// clang-format on
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "sherpa-onnx/c-api/c-api.h"
+
+static int32_t ProgressCallback(const float *samples, int32_t num_samples,
+                                float progress) {
+  fprintf(stderr, "Progress: %.3f%%\n", progress * 100);
+  // return 1 to continue generating
+  // return 0 to stop generating
+  return 1;
+}
+
+int32_t main(int32_t argc, char *argv[]) {
+  SherpaOnnxOfflineTtsConfig config;
+  memset(&config, 0, sizeof(config));
+  config.model.kokoro.model = "./kokoro-en-v0_19/model.onnx";
+  config.model.kokoro.voices = "./kokoro-en-v0_19/voices.bin";
+  config.model.kokoro.tokens = "./kokoro-en-v0_19/tokens.txt";
+  config.model.kokoro.data_dir = "./kokoro-en-v0_19/espeak-ng-data";
+
+  config.model.num_threads = 2;
+
+  // If you don't want to see debug messages, please set it to 0
+  config.model.debug = 1;
+
+  const char *filename = "./generated-kokoro-en.wav";
+  const char *text =
+      "Today as always, men fall into two groups: slaves and free men. Whoever "
+      "does not have two-thirds of his day for himself, is a slave, whatever "
+      "he may be: a statesman, a businessman, an official, or a scholar. "
+      "Friends fell out often because life was changing so fast. The easiest "
+      "thing in the world was to lose touch with someone.";
+
+  const SherpaOnnxOfflineTts *tts = SherpaOnnxCreateOfflineTts(&config);
+  // mapping of sid to voice name
+  // 0->af, 1->af_bella, 2->af_nicole, 3->af_sarah, 4->af_sky, 5->am_adam
+  // 6->am_michael, 7->bf_emma, 8->bf_isabella, 9->bm_george, 10->bm_lewis
+  int32_t sid = 0;
+  float speed = 1.0;  // larger -> faster in speech speed
+
+#if 0
+  // If you don't want to use a callback, then please enable this branch
+  const SherpaOnnxGeneratedAudio *audio =
+      SherpaOnnxOfflineTtsGenerate(tts, text, sid, speed);
+#else
+  const SherpaOnnxGeneratedAudio *audio =
+      SherpaOnnxOfflineTtsGenerateWithProgressCallback(tts, text, sid, speed,
+                                                       ProgressCallback);
+#endif
+
+  SherpaOnnxWriteWave(audio->samples, audio->n, audio->sample_rate, filename);
+
+  SherpaOnnxDestroyOfflineTtsGeneratedAudio(audio);
+  SherpaOnnxDestroyOfflineTts(tts);
+
+  fprintf(stderr, "Input text is: %s\n", text);
+  fprintf(stderr, "Speaker ID is is: %d\n", sid);
+  fprintf(stderr, "Saved to: %s\n", filename);
+
+  return 0;
+}