Support user provided data in tts callback. (#653)

@@ -636,6 +636,32 @@ const SherpaOnnxGeneratedAudio *SherpaOnnxOfflineTtsGenerateWithCallback(
   return ans;
 }
 
+const SherpaOnnxGeneratedAudio *SherpaOnnxOfflineTtsGenerateWithCallbackWithArg(
+    const SherpaOnnxOfflineTts *tts, const char *text, int32_t sid, float speed,
+    SherpaOnnxGeneratedAudioCallbackWithArg callback, void *arg) {
+  auto wrapper = [callback, arg](const float *samples, int32_t n) {
+    callback(samples, n, arg);
+  };
+
+  sherpa_onnx::GeneratedAudio audio =
+      tts->impl->Generate(text, sid, speed, wrapper);
+
+  if (audio.samples.empty()) {
+    return nullptr;
+  }
+
+  SherpaOnnxGeneratedAudio *ans = new SherpaOnnxGeneratedAudio;
+
+  float *samples = new float[audio.samples.size()];
+  std::copy(audio.samples.begin(), audio.samples.end(), samples);
+
+  ans->samples = samples;
+  ans->n = audio.samples.size();
+  ans->sample_rate = audio.sample_rate;
+
+  return ans;
+}
+
 void SherpaOnnxDestroyOfflineTtsGeneratedAudio(
     const SherpaOnnxGeneratedAudio *p) {
   if (p) {

@@ -644,6 +644,9 @@ SHERPA_ONNX_API typedef struct SherpaOnnxGeneratedAudio {
 typedef void (*SherpaOnnxGeneratedAudioCallback)(const float *samples,
                                                  int32_t n);
 
+typedef void (*SherpaOnnxGeneratedAudioCallbackWithArg)(const float *samples,
+                                                        int32_t n, void *arg);
+
 SHERPA_ONNX_API typedef struct SherpaOnnxOfflineTts SherpaOnnxOfflineTts;
 
 // Create an instance of offline TTS. The user has to use DestroyOfflineTts()
@@ -678,6 +681,13 @@ SherpaOnnxOfflineTtsGenerateWithCallback(
     const SherpaOnnxOfflineTts *tts, const char *text, int32_t sid, float speed,
     SherpaOnnxGeneratedAudioCallback callback);
 
+// Same as SherpaOnnxGeneratedAudioCallback but you can pass an additional
+// `void* arg` to the callback.
+SHERPA_ONNX_API const SherpaOnnxGeneratedAudio *
+SherpaOnnxOfflineTtsGenerateWithCallbackWithArg(
+    const SherpaOnnxOfflineTts *tts, const char *text, int32_t sid, float speed,
+    SherpaOnnxGeneratedAudioCallbackWithArg callback, void *arg);
+
 SHERPA_ONNX_API void SherpaOnnxDestroyOfflineTtsGeneratedAudio(
     const SherpaOnnxGeneratedAudio *p);
 

@@ -43,5 +43,3 @@ void PybindAlsa(py::module *m) {
 }
 
 }  // namespace sherpa_onnx
-
-#endif  // SHERPA_ONNX_PYTHON_CSRC_FAKED_ALSA_H_