+/*
+ * Copyright (c) 2011-2016 Samsung Electronics Co., Ltd All Rights Reserved
+ *
+ * Licensed under the Apache License, Version 2.0 (the License);
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __STT_INTERNAL_H__
+#define __STT_INTERNAL_H__
+
+#include <tizen.h>
+
+/**
+ * @file stt_internal.h
+ */
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#define STT_SPEECH_STATUS_BEGINNING_POINT_DETECTED 0
+
+/**
+ * @brief Called when user speaking is detected.
+ *
+ * @param[in] stt The STT handle
+ * @param[in] status The speech status
+ * @param[in] user_data The user data passed from the callback registration function
+ *
+ * @pre An application registers callback function using stt_set_speech_status_cb().
+ *
+ * @see stt_set_speech_status_cb()
+ * @see stt_unset_speech_status_cb()
+ */
+typedef void (*stt_speech_status_cb)(stt_h stt, int status, void *user_data);
+
+
+/**
+ * @brief Registers a callback function to detect the speech status is changed.
+ * @since_tizen 3.0
+ * @privilege %http://tizen.org/privilege/recorder
+ *
+ * @param[in] stt The STT handle
+ * @param[in] callback The callback function to register
+ * @param[in] user_data The user data to be passed to the callback function
+ *
+ * @return 0 on success, otherwise a negative error value
+ * @retval #STT_ERROR_NONE Successful
+ * @retval #STT_ERROR_INVALID_PARAMETER Invalid parameter
+ * @retval #STT_ERROR_INVALID_STATE Invalid state
+ * @retval #STT_ERROR_NOT_SUPPORTED STT NOT supported
+ * @retval #STT_ERROR_PERMISSION_DENIED Permission denied
+ *
+ * @pre The state should be #STT_STATE_CREATED.
+ *
+ * @see stt_speech_status_cb()
+ * @see stt_unset_speech_status_cb()
+*/
+int stt_set_speech_status_cb(stt_h stt, stt_speech_status_cb callback, void* user_data);
+
+/**
+ * @brief Unregisters the callback function.
+ * @since_tizen 3.0
+ * @privilege %http://tizen.org/privilege/recorder
+ *
+ * @param[in] stt The STT handle
+ *
+ * @return 0 on success, otherwise a negative error value
+ * @retval #STT_ERROR_NONE Successful
+ * @retval #STT_ERROR_INVALID_PARAMETER Invalid parameter
+ * @retval #STT_ERROR_INVALID_STATE Invalid state
+ * @retval #STT_ERROR_NOT_SUPPORTED STT NOT supported
+ * @retval #STT_ERROR_PERMISSION_DENIED Permission denied
+ *
+ * @pre The state should be #STT_STATE_CREATED.
+ *
+ * @see stt_set_speech_status_cb()
+*/
+int stt_unset_speech_status_cb(stt_h stt);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**
+ * @}@}
+ */
+
+#endif /* __STT_INTERNAL_H__ */
+