1 /* 2 * Copyright (C) 2009 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 #include <media/AudioSystem.h> 17 18 // This header defines the interface used by the Android platform 19 // to access Text-To-Speech functionality in shared libraries that implement 20 // speech synthesis and the management of resources associated with the 21 // synthesis. 22 // An example of the implementation of this interface can be found in 23 // FIXME: add path+name to implementation of default TTS engine 24 // Libraries implementing this interface are used in: 25 // frameworks/base/tts/jni/android_tts_SpeechSynthesis.cpp 26 27 namespace android { 28 29 #define ANDROID_TTS_ENGINE_PROPERTY_CONFIG "engineConfig" 30 #define ANDROID_TTS_ENGINE_PROPERTY_PITCH "pitch" 31 #define ANDROID_TTS_ENGINE_PROPERTY_RATE "rate" 32 #define ANDROID_TTS_ENGINE_PROPERTY_VOLUME "volume" 33 34 35 enum tts_synth_status { 36 TTS_SYNTH_DONE = 0, 37 TTS_SYNTH_PENDING = 1 38 }; 39 40 enum tts_callback_status { 41 TTS_CALLBACK_HALT = 0, 42 TTS_CALLBACK_CONTINUE = 1 43 }; 44 45 // The callback is used by the implementation of this interface to notify its 46 // client, the Android TTS service, that the last requested synthesis has been 47 // completed. // TODO reword 48 // The callback for synthesis completed takes: 49 // @param [inout] void *& - The userdata pointer set in the original 50 // synth call 51 // @param [in] uint32_t - Track sampling rate in Hz 52 // @param [in] uint32_t - The audio format 53 // @param [in] int - The number of channels 54 // @param [inout] int8_t *& - A buffer of audio data only valid during the 55 // execution of the callback 56 // @param [inout] size_t & - The size of the buffer 57 // @param [in] tts_synth_status - indicate whether the synthesis is done, or 58 // if more data is to be synthesized. 59 // @return TTS_CALLBACK_HALT to indicate the synthesis must stop, 60 // TTS_CALLBACK_CONTINUE to indicate the synthesis must continue if 61 // there is more data to produce. 62 typedef tts_callback_status (synthDoneCB_t)(void *&, uint32_t, 63 uint32_t, int, int8_t *&, size_t&, tts_synth_status); 64 65 class TtsEngine; 66 extern "C" TtsEngine* getTtsEngine(); 67 68 enum tts_result { 69 TTS_SUCCESS = 0, 70 TTS_FAILURE = -1, 71 TTS_FEATURE_UNSUPPORTED = -2, 72 TTS_VALUE_INVALID = -3, 73 TTS_PROPERTY_UNSUPPORTED = -4, 74 TTS_PROPERTY_SIZE_TOO_SMALL = -5, 75 TTS_MISSING_RESOURCES = -6 76 }; 77 78 enum tts_support_result { 79 TTS_LANG_COUNTRY_VAR_AVAILABLE = 2, 80 TTS_LANG_COUNTRY_AVAILABLE = 1, 81 TTS_LANG_AVAILABLE = 0, 82 TTS_LANG_MISSING_DATA = -1, 83 TTS_LANG_NOT_SUPPORTED = -2 84 }; 85 86 class TtsEngine 87 { 88 public: ~TtsEngine()89 virtual ~TtsEngine() {} 90 91 // Initialize the TTS engine and returns whether initialization succeeded. 92 // @param synthDoneCBPtr synthesis callback function pointer 93 // @return TTS_SUCCESS, or TTS_FAILURE 94 virtual tts_result init(synthDoneCB_t synthDoneCBPtr, const char *engineConfig); 95 96 // Shut down the TTS engine and releases all associated resources. 97 // @return TTS_SUCCESS, or TTS_FAILURE 98 virtual tts_result shutdown(); 99 100 // Interrupt synthesis and flushes any synthesized data that hasn't been 101 // output yet. This will block until callbacks underway are completed. 102 // @return TTS_SUCCESS, or TTS_FAILURE 103 virtual tts_result stop(); 104 105 // Returns the level of support for the language, country and variant. 106 // @return TTS_LANG_COUNTRY_VAR_AVAILABLE if the language, country and variant are supported, 107 // and the corresponding resources are correctly installed 108 // TTS_LANG_COUNTRY_AVAILABLE if the language and country are supported and the 109 // corresponding resources are correctly installed, but there is no match for 110 // the specified variant 111 // TTS_LANG_AVAILABLE if the language is supported and the 112 // corresponding resources are correctly installed, but there is no match for 113 // the specified country and variant 114 // TTS_LANG_MISSING_DATA if the required resources to provide any level of support 115 // for the language are not correctly installed 116 // TTS_LANG_NOT_SUPPORTED if the language is not supported by the TTS engine. 117 virtual tts_support_result isLanguageAvailable(const char *lang, const char *country, 118 const char *variant); 119 120 // Load the resources associated with the specified language. The loaded 121 // language will only be used once a call to setLanguage() with the same 122 // language value is issued. Language and country values are coded according to the ISO three 123 // letter codes for languages and countries, as can be retrieved from a java.util.Locale 124 // instance. The variant value is encoded as the variant string retrieved from a 125 // java.util.Locale instance built with that variant data. 126 // @param lang pointer to the ISO three letter code for the language 127 // @param country pointer to the ISO three letter code for the country 128 // @param variant pointer to the variant code 129 // @return TTS_SUCCESS, or TTS_FAILURE 130 virtual tts_result loadLanguage(const char *lang, const char *country, const char *variant); 131 132 // Load the resources associated with the specified language, country and Locale variant. 133 // The loaded language will only be used once a call to setLanguageFromLocale() with the same 134 // language value is issued. Language and country values are coded according to the ISO three 135 // letter codes for languages and countries, as can be retrieved from a java.util.Locale 136 // instance. The variant value is encoded as the variant string retrieved from a 137 // java.util.Locale instance built with that variant data. 138 // @param lang pointer to the ISO three letter code for the language 139 // @param country pointer to the ISO three letter code for the country 140 // @param variant pointer to the variant code 141 // @return TTS_SUCCESS, or TTS_FAILURE 142 virtual tts_result setLanguage(const char *lang, const char *country, const char *variant); 143 144 // Retrieve the currently set language, country and variant, or empty strings if none of 145 // parameters have been set. Language and country are represented by their 3-letter ISO code 146 // @param[out] pointer to the retrieved 3-letter code language value 147 // @param[out] pointer to the retrieved 3-letter code country value 148 // @param[out] pointer to the retrieved variant value 149 // @return TTS_SUCCESS, or TTS_FAILURE 150 virtual tts_result getLanguage(char *language, char *country, char *variant); 151 152 // Notifies the engine what audio parameters should be used for the synthesis. 153 // This is meant to be used as a hint, the engine implementation will set the output values 154 // to those of the synthesis format, based on a given hint. 155 // @param[inout] encoding in: the desired audio sample format 156 // out: the format used by the TTS engine 157 // @param[inout] rate in: the desired audio sample rate 158 // out: the sample rate used by the TTS engine 159 // @param[inout] channels in: the desired number of audio channels 160 // out: the number of channels used by the TTS engine 161 // @return TTS_SUCCESS, or TTS_FAILURE 162 virtual tts_result setAudioFormat(AudioSystem::audio_format& encoding, uint32_t& rate, 163 int& channels); 164 165 // Set a property for the the TTS engine 166 // "size" is the maximum size of "value" for properties "property" 167 // @param property pointer to the property name 168 // @param value pointer to the property value 169 // @param size maximum size required to store this type of property 170 // @return TTS_PROPERTY_UNSUPPORTED, or TTS_SUCCESS, or TTS_FAILURE, 171 // or TTS_VALUE_INVALID 172 virtual tts_result setProperty(const char *property, const char *value, 173 const size_t size); 174 175 // Retrieve a property from the TTS engine 176 // @param property pointer to the property name 177 // @param[out] value pointer to the retrieved language value 178 // @param[inout] iosize in: stores the size available to store the 179 // property value. 180 // out: stores the size required to hold the language 181 // value if getLanguage() returned 182 // TTS_PROPERTY_SIZE_TOO_SMALL, unchanged otherwise 183 // @return TTS_PROPERTY_UNSUPPORTED, or TTS_SUCCESS, 184 // or TTS_PROPERTY_SIZE_TOO_SMALL 185 virtual tts_result getProperty(const char *property, char *value, 186 size_t *iosize); 187 188 // Synthesize the text. 189 // As the synthesis is performed, the engine invokes the callback to notify 190 // the TTS framework that it has filled the given buffer, and indicates how 191 // many bytes it wrote. The callback is called repeatedly until the engine 192 // has generated all the audio data corresponding to the text. 193 // Note about the format of the input: the text parameter may use the 194 // following elements 195 // and their respective attributes as defined in the SSML 1.0 specification: 196 // * lang 197 // * say-as: 198 // o interpret-as 199 // * phoneme 200 // * voice: 201 // o gender, 202 // o age, 203 // o variant, 204 // o name 205 // * emphasis 206 // * break: 207 // o strength, 208 // o time 209 // * prosody: 210 // o pitch, 211 // o contour, 212 // o range, 213 // o rate, 214 // o duration, 215 // o volume 216 // * mark 217 // Differences between this text format and SSML are: 218 // * full SSML documents are not supported 219 // * namespaces are not supported 220 // Text is coded in UTF-8. 221 // @param text the UTF-8 text to synthesize 222 // @param userdata pointer to be returned when the call is invoked 223 // @param buffer the location where the synthesized data must be written 224 // @param bufferSize the number of bytes that can be written in buffer 225 // @return TTS_SUCCESS or TTS_FAILURE 226 virtual tts_result synthesizeText(const char *text, int8_t *buffer, 227 size_t bufferSize, void *userdata); 228 229 }; 230 231 } // namespace android 232 233