Added progress for callback of tts generator (#712)

Co-authored-by: leohwang <leohwang@360converter.com>

sherpa-onnx/python/csrc/offline-tts.cc

@@ -55,14 +55,14 @@ void PybindOfflineTts(py::module *m) {
       .def(
           "generate",
           [](const PyClass &self, const std::string &text, int64_t sid,
-             float speed, std::function<void(py::array_t<float>)> callback)
+             float speed, std::function<void(py::array_t<float>, float)> callback)
               -> GeneratedAudio {
             if (!callback) {
               return self.Generate(text, sid, speed);
             }
 
-            std::function<void(const float *, int32_t)> callback_wrapper =
-                [callback](const float *samples, int32_t n) {
+            std::function<void(const float *, int32_t, float)> callback_wrapper =
+                [callback](const float *samples, int32_t n, float progress) {
                   // CAUTION(fangjun): we have to copy samples since it is
                   // freed once the call back returns.
 
@@ -72,7 +72,7 @@ void PybindOfflineTts(py::module *m) {
                   py::buffer_info buf = array.request();
                   auto p = static_cast<float *>(buf.ptr);
                   std::copy(samples, samples + n, p);
-                  callback(array);
+                  callback(array, progress);
                 };
 
             return self.Generate(text, sid, speed, callback_wrapper);